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Fibrous Dysplasia Involving the Skull Base and Temporal Bone
Lawrence R. Lustig, MD;
Michael J. Holliday, MD;
Edward F. McCarthy;
George T. Nager, MD
Arch Otolaryngol Head Neck Surg. 2001;127:1239-1247.
ABSTRACT
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Objective To gain a broader appreciation of the clinical presentation, operative
treatment, and outcome of patients with fibrous dysplasia involving the skull
base.
Design Retrospective review of a clinical case series.
Setting A single tertiary academic medical center.
Patients Twenty-one patients with histopathologically confirmed fibrous dysplasia
involving the skull base cared for over a 15-year-period (1983-1998).
Main Outcome Measures Clinical and radiographic location of the fibrous dysplasia lesions
within the skull base, clinical presentation, surgical intervention, and clinical
outcome were tabulated for each patient.
Results The ethmoids were most commonly involved (71%), followed by the sphenoid
(43%), frontal (33%), maxilla (29%), temporal (24%), parietal (14%), and occipital
(5%) bones. The most common presenting features included atypical facial pain
and headache, complaints referable to the sinuses, proptosis and diplopia,
hearing loss, and facial numbness. Surgical treatment, guided by clinical
presentation, ranged from simple biopsy with conservative follow-up to craniofacial
resection.
Conclusions Fibrous dysplasia can present in myriad ways within the skull base.
Modern imaging modalities and histopathologic analysis have made diagnosis
relatively straightforward. Surgery, particularly in such a challenging region
as the skull base, should be reserved for patients with functional impairment
or a cosmetic deformity. Because of the benign nature of the condition, the
surgery itself should be relatively conservative, with the primary goal being
preservation of existing function.
INTRODUCTION
FIBROUS DYSPLASIA is a localized disorder of bone characterized by abnormal
proliferation of fibrous tissue interspersed with normal or immature bone,
endocrine dysfunction, abnormal pigmentation, and precocious puberty in girls.
The entity is not a new one. Although von Recklinghausen,1
a student of Virchow, is credited with the first accurate pathologic description
of the disorder in 1891, characteristic lesions have been identified in prehistoric
specimens and in a seventh-century Anglo-Saxon.2-3
McCune and Bruch4 and Albright and coworkers5 recognized in separate publications in 1937 the entity
of osteodystrophia fibrosa disseminata, characterized
by endocrinopathies, cutaneous hyperpigmentation, and precocious puberty in
females. This severe form of fibrous dysplasia subsequently became known as
the Albright triad or McCune-Albright
syndrome.6 The terms fibrous dysplasia and polyostotic fibrous dysplasia were first suggested by Lichtenstein in 1938.7
Currently, 3 general subtypes of disease are recognized: monostotic,
polyostotic, and McCune-Albright syndrome. The monostotic form is the mildest
and most common form (approximately 70% of cases), is noted for lesions involving
the ribs and craniofacial bones, and is typically diagnosed between ages 20
and 30 years. The incidence of the monostotic form may be even higher than
the quoted figure of 70% because these lesions often remain asymptomatic.6 The polyostotic form (30% of cases) has an earlier
onset, typically in childhood, and affected patients tend to have more severe
skeletal and craniofacial involvement. The most severe form of the disorder,
McCune-Albright syndrome (3% of cases), is more commonly found (although not
exclusively) in females, is associated with short stature due to premature
closure of the epiphyses, and is associated with endocrine abnormalities and
pigmented cutaneous lesions.8 Although this
classification scheme implies a related gradation of severity, the monostotic
form is not believed to be a precursor to the polyostotic form; there are
no reports of transition from one to the other, and the two manifest different
frequencies and severity toward spontaneous fractures, deformities, and long-term
clinical behavior, leading to speculation that the 2 types are not as closely
related as their histologic similarity suggests.6, 9-10
This dispute of whether the 2 forms are gradations of the same process or
distinct diseases with similar pathologic manifestations should in all likelihood
be resolved once the genetics of the disorder are elucidated.
The precise etiology of fibrous dysplasia is currently unknown. In 1942,
Lichtenstein and Jaffe11 proposed abnormal
differentiation of mesenchyme as a cause of the bony abnormalities. In 1957,
Changus12 proposed osteoblastic hyperplasia
as the underlying pathologic process in fibrous dysplasia. Theories put forward
in the 1960s regarding etiology also included arrest of bone at an immature
woven stage and a disturbance of postnatal cancellous bone maintenance.13-14
More recent attempts to define the disorder have focused on its underlying
genetics and molecular biology. Lee and coworkers15
proposed that abnormal intracellular regulation of cyclic adenosine monophosphate
or protein kinase A is a possible etiologic factor in the development of fibrous
dysplasia. Several other researchers16-18
have identified mutations in the Gs- gene, resulting in
altered activity of intrinsic GTPase activity or the Gs protein
signal transduction pathway as a cause of fibrous dysplasia. It has thus been
postulated that the pattern and distribution of fibrous dysplasia depends
on which tissues contain the mutated Gs- (GNAS1) gene and is in turn affected by such factors as genomic imprinting.19 During the next several years, as the underlying
molecular biology of the disorder becomes elucidated, the true etiology of
fibrous dysplasia will also be resolved.
Although fibrous dysplasia specifically involving the temporal bone
has been described in several case reports and series, its impact on the broader
skull base is not as well documented in the literature. In an effort to gain
an improved appreciation for the clinical spectrum of this disorder, we performed
a retrospective review of all patients with fibrous dysplasia involving the
temporal bone and skull base evaluated at The Johns Hopkins University, Baltimore,
Md, over a 15-year period (1983-1998). The clinical presentation, evaluation,
and recommended treatment of the disorder in light of its benign nature are
reviewed.
MATERIALS AND METHODS
All patients with a diagnosis of fibrous dysplasia involving at least
a portion of the cranial base in the past 15 years were retrospectively identified
through reviews of clinical charts and computerized pathologic records at
The Johns Hopkins Hospital. Clinical information was gathered from patient
records and included age of onset and presenting symptoms and signs of the
skull base lesion, treatment course, and clinical outcome for each patient.
Radiologic scans, either computed tomography (CT) or magnetic resonance imaging
(MRI), were obtained when possible; radiographic information was otherwise
obtained from reports or notations in medical records. All patients had histopathologic
confirmation of their diagnosis. Patients were not included in this series
if adequate histories and relevant radiographic data, as outlined previously,
could not be obtained. Several patients included in this series have been
described previously as case reports.8, 20
RESULTS
PATIENT DEMOGRAPHICS
A total of 21 patients were identified with fibrous dysplasia involving
at least one aspect of the cranial base (Table 1 and Table 2).
Average age at presentation was 22 years (range, 8-54 years). Thirteen patients
were younger than 20 years at presentation. There was a 2:1 male-female ratio
(14 males and 7 females).
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Table 1. Anatomic Location and Clinical Presentation of Fibrous Dysplasia
Lesions in 21 Patients
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Table 2. Individual Patient Data
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Six patients were classified as having monostotic fibrous dysplasia
based on involvement of only a single bone; these patients had an isolated
skull base lesion without manifestations of fibrous dysplasia in the remainder
of the body. Fifteen patients were classified as having polyostotic fibrous
dysplasia because of involvement of multiple bones throughout the skull base
or remainder of their body. Of the 15 patients with polyostotic disease, 2
(both males) were designated as having McCune-Albright syndrome based on associated
systemic cutaneous and endocrine anomalies.
ANATOMIC LOCATION OF LESIONS
Anatomically, the most commonly involved area of the skull base was
the ethmoid bone (71% of patients) (Table
1 and Table 2). In only
1 patient was the ethmoid solely involved (Figure 1); the remaining patients with ethmoid disease had involvement
of adjacent areas of the skull base, including the sphenoid (most common),
followed by the maxilla (Figure 2)
and frontal (Figure 3) bones. The
next most common area of skull base involvement was the sphenoid bone (43%),
followed by the frontal bone (33%) (Figure
4)20 and maxilla (29%). Similarly,
no patient presented with isolated maxillary disease; all had at least some
radiographic involvement of the ethmoids. Taking into account all bones making
up the sinus cavities, overall the sinuses were involved in 17 (81%) of 21
patients.
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Figure 1. Axial computed tomographic scan
of a solitary cystic fibrous dysplasia lesion involving the right ethmoid
sinus (arrow). This 55-year-old man presented with retro-orbital pain and
headaches. Presumptively diagnosed as having an ethmoid mucocele, the patient
underwent endoscopic biopsy and decompression of the lesion. Final pathologic
diagnosis was consistent with fibrous dysplasia. Since surgery, the patient
has remained free of headaches with follow-up of 4 years, with no evidence
of growth of the remainder of the lesion by computed tomography.
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Figure 2. Coronal computed tomographic scan
of a 5-cm fibrous dysplasia lesion involving the maxilla and ethmoid bones
(arrows). The 14-year-old patient originally presented with left-sided facial
swelling. Because of a concern for low-grade malignancy, complete resection
of the lesion was performed. The lesion was classified as fibrous dysplasia
with aneurysmal bone cyst formation. The patient had a good surgical outcome
and was doing well without recurrence 2 years after the initial procedure.
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Figure 3. Axial computed tomographic scan
of a patient with fibrous dysplasia involving the frontal (A) and ethmoid
and sphenoid bones (B).
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Figure 4. Axial computed tomographic scan
of a large 5-cm extra-axial fibrous dysplasia aneurysmal bone cyst of the
frontal bone (arrow). In addition, the calvarium is diffusely thickened with
a heterogeneous, "ground-glass" appearance, consistent with fibrous dysplasia.
This 40-year-old man with a history of severe polyostotic fibrous dysplasia
presented with an expanding mass of his left frontal bone after mild head
trauma. The patient complained of a bulging left eye, made worse by manually
compressing the mass. On examination, compression on the obvious frontal mass
caused increased proptosis. The patient underwent left frontal craniotomy,
cyst drainage, cystoethmoidectomy, and closure with a pericranial flap, which
resulted in alleviation of the proptosis and flattening of the forehead deformity.
A follow-up scan 2 years after the drainage procedure demonstrated no change
in size of the decompressed cystic mass, and the patient remained asymptomatic
with regard to the lesion. This patient has been described previously by Wojno
and McCarthy.20
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Five patients had fibrous dysplasia involving the temporal bones: 2
were totally asymptomatic from their temporal bone lesions and had radiographic
involvement only (Figure 5), 1 had
McCune-Albright syndrome with widespread skull base involvement, and 1 had
polyostotic disease with primarily frontal sinus symptoms. Of the 3 patients
with symptomatic temporal bone involvement, 2 had true monostotic forms of
fibrous dysplasia, with the temporal bone lesion being the only manifestation
of the disease in the body (Figure 6).
The third patient had McCune-Albright syndrome and widespread skull base involvement
(Figure 7).
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Figure 5. Axial computed tomographic scan
of an extensive fibrous dysplasia lesion involving the sphenoid and temporal
bones (arrows). The patient presented with symptoms of orbital compression
and proptosis. There were no symptoms related to the temporal bone involvement.
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Figure 6. Axial computed tomographic scan
demonstrating an aneurysmal bone cyst of the temporal bone (arrow). The patient
underwent a right middle cranial fossa approach for biopsy of the lesion,
and diagnosis of fibrous dysplasia was made histopathologically.
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Figure 7. Axial computed tomographic scan
demonstrating extensive fibrous dysplasia involving the entire skull base.
A, Involvement of the ethmoid and sphenoid regions. B, Diffuse involvement
of the temporal, parietal, and frontal bones in this same patient.
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Three patients presented with parietal skull involvement: 1 with monostotic
disease had an isolated bony lesion in the parietal skull and the 2 other
with parietal involvement had widespread involvement of the entire base of
the skull (Figure 7 and Figure 8). Similarly, the patient with occipital
bone involvement had widespread disease throughout the skull base (Figure 7).
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Figure 8. Coronal T1-weighted magnetic resonance
image of an isointense fibrous dysplasia lesion involving the sphenoid bone
(arrow). The patient presented with headaches and visual and cognitive changes.
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CLINICAL FEATURES
The most common complaint at presentation was atypical facial pain or
headache (57%), followed by sinus congestion or infection that was initially
interpreted as sinusitis (43%) (Table 1 and Table 2). Orbital
involvement, manifested as proptosis, diplopia, or visual changes, was identified
in 43% of patients. The presence of an expanding facial or skull mass led
to the diagnosis in 24% of patients. Hearing loss and facial numbness were
identified as presenting symptoms in 2 patients each (10%).
All patients underwent some form of surgical biopsy or excision for
diagnosis. Of patients with extensive sinus involvement (ethmoid, frontal,
maxillary, and sphenoid), surgery was performed to relieve diplopia or proptosis
resulting from impingement on orbital contents in 5 (patients 5, 6, 10, 11,
18 in Table 2). In all 5 patients,
surgery was performed via an external ethmoidectomy or lateral rhinotomy–type
approach. One of these patients also required facial degloving and craniofacial
resection for extensive orbital rim involvement. The symptoms of proptosis
were improved in 4 of the 5 patients and stabilized during follow-up. Of the
6 patients with maxillary sinus involvement (patients 4, 5, 10, 15, 17, and
19 in Table 2), 2 underwent a
medial maxillectomy and 3 underwent limited transantral resection of the disease.
Another patient with McCune-Albright syndrome and widespread skull base disease
and a large aneurysmal bone cyst involving the frontal sinuses (Figure 4), impinging on the frontal lobe, required a cranioplasty
with cystoethmoidostomy and pericranial closure of the defect.
Of the 5 patients with temporal bone involvement (patients 1, 4, 7,
12, and 21 in Table 2), 3 required
surgical intervention due to the temporal bone disease. Two of these patients
had lesions that were primarily manifest as external auditory canal stenosis
(patients 1 and 7). These 2 patients underwent canalplasty, meatoplasty, and
placement of Silastic stents in the external auditory canal with subsequent
periodic curettage, which has controlled the canal stenosis for the 17 to
30 years they have been followed up. One of these was a patient with McCune-Albright
syndrome with a previous history of bilateral radical mastoidectomies 20 years
previously. The third patient had a large cystic lesion expending into the
middle cranial fossa and, because of concern for the presence of a neoplastic
lesion, underwent a middle fossa approach for diagnosis and excision of the
lesion (patient 12 in Figure 6).
The lesion has not recurred during 10-year follow-up.
Of the 3 patients with parietal skull involvement (patients 2-4 in Table 2), only 1 presented undiagnosed
with a solitary lesion. This patient underwent surgical biopsy and excision
and did well, with no recurrence in the subsequent 13 years. The other 2 patients
did not require surgical intervention as a result of their parietal lesions
and have been managed conservatively by observation.
COMMENT
This clinical series demonstrates the numerous ways in which fibrous
dysplasia involving the skull base can present. In many respects, the series
differs from previous reports on fibrous dysplasia. Determining the true incidence
of fibrous dysplasia, particularly for the more prevalent monostotic form,
is difficult because many patients are asymptomatic and are often diagnosed
incidentally after radiographic evaluation for other reasons. Onset is typically
in adolescence or late childhood, although more severe forms can arise in
infancy. Average age at presentation in this study was 22 years, and the median
age was 17 years. Whereas both monostotic and polyostotic forms occur with
equal frequency in males and females, McCune-Albright syndrome has a clear
female predilection. It is therefore somewhat unusual that there was a 2:1
male-female ratio in this series and that both patients with McCune-Albright
syndrome in this study were male. However, the high percentage of children
in this series may account for the male predilection we identified; as Spjut
and coworkers21 noted, among young adults,
more males than females are affected.
The relative numbers of patients with monostotic vs polyostotic disease
in this study are also different than those reported in the general fibrous
dysplasia literature, where the polyostotic form typically represents only
about one third of patients.22 In this study,
6 patients were classified as having monostotic fibrous dysplasia and 15 had
the polyostotic form. This difference is probably due to the focus on skull
base disease in this study. The craniofacial bones are typically involved
in approximately 10% of patients with the monostotic form and in 50% with
the polyostotic form, although in severe polyostotic cases, craniofacial involvement
can approach 100%.22 Thus, the inclusion of
only patients with skull base disease would account for the higher number
of patients with the polyostotic form seen in this study.
This study also differs from previous studies with regard to the location
of fibrous dysplasia lesions involving the skull base. Van Tillburg23 analyzed skull lesions from 144 patients identified
in the literature and noted that the frontal bones were most commonly involved,
followed by the sphenoid, ethmoid, parietal, temporal, and occipital bones.
This is in contrast to our findings, which identified the ethmoid as the most
commonly involved bone, followed by the sphenoid, frontal, maxilla, temporal,
parietal, and occipital bones. This difference can probably be most readily
attributable to improved radiographic diagnosis using CT and MRI (the study
by Van Tillburg was published in 1972, before our current standard imaging
modalities). These newer modalities are not only able to identify asymptomatic
involved areas of the skull base with improved accuracy, they are also superior
at diagnosing ethmoid and sphenoid lesions compared with plain radiographs.
Consequently, the anatomic breakdown offered here is probably more accurate
than in studies before the inclusion of CT or MRI analysis.
Clinically, atypical facial pain and headache were the most common presenting
features, followed by symptoms suggestive of sinusitis. This is not surprising
given the overwhelming number of patients in the study who presented with
fibrous dysplasia involving the sinuses (81%). The fact that 9 of 21 patients
also had visual changes, including proptosis and diplopia, also relates to
the preponderance of ethmoid, sphenoid, and frontal bone involvement in many
patients. Through progressive enlargement, the lesions most commonly cause
symptoms in the orbit by pressure and displacement of orbital contents. Facial
numbness was noted in 2 patients at presentation, both of whom had maxillary
lesions, with the dysethesia due to involvement of the infraorbital nerve.
Of the 5 patients with temporal bone involvement, only 3 were symptomatic
at presentation; 2 patients had only radiographic involvement. Two of the
symptomatic patients had conductive hearing loss related to external auditory
canal stenosis, and the third had headaches. These are typical presenting
symptoms of fibrous dysplasia involving the skull base that have been noted
by other authors.24
Three classic radiologic findings of fibrous dysplasia are described:
pagetoid, sclerotic, and myxoid.10 However,
these classic radiographic descriptions are based on plain films, which have
little relevance with the nearly universal access to modern imaging techniques
such as CT and MRI. In this series spanning the past 15 years, plain films
played no role in the diagnosis, management, or follow-up of any patients.
Computed tomography is the study of choice for diagnosis and follow-up because
of its superior bony detail and accurate assessment of the extent of the lesion.
Furthermore, CT can often assist with differentiating fibrous dysplasia from
other osteodystrophies of the skull base, including otosclerosis, osteogenesis
imperfecta, Paget disease, and osteopetrosis.25
Distinguishing features of fibrous dysplasia on CT include (in order of significance)
"ground-glass" appearance, symmetry, involvement of the paranasal sinuses,
thickness of the cranial cortices, involvement of the sphenoid bone, orbital
involvement, nasal cavity involvement, presence of a soft tissue mass, maxillary
involvement, and the presence of cystlike changes (Figure 1, Figure 2, Figure 3, Figure 4, Figure 5, Figure 6, Figure 7, and Figure 8, Figure 9). 26
There is often a clear margin between affected and unaffected bone. Aneurysmal
bone cyst formation is also readily apparent on CT. These lesions appear cystic
with a bony shell, with either a fluid or soft tissue–appearing center
(Figure 2, Figure 5, Figure 6, and Figure 9). Magnetic resonance imaging is
an additional useful modality that can help distinguish fibrous dysplasia
from meningioma, osteoma, or mucocele and define the extent of soft tissue
involvement, particularly if central nervous system structures are impinged
on. Lesions are typically low to isointense on T1- and T2-weighted images
and show moderate to marked enhancement with gadolinium (Figure 8 and Figure 9).25, 27
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Figure 9. Axial T1-weighted magnetic resonance
image with gadolinium of a fibrous dysplasia lesion involving the ethmoid
and sphenoid bones (arrows). The mass extends into the nasopharynx and is
continuous with the skull base. The lesion is of low-signal intensity that
enhances heterogeneously with gadolinium. This previously healthy 31-year-old
man presented only with visual changes with exercise. He had no additional
complaints, and results of his physical examination were normal. To obtain
a diagnosis, a transnasal biopsy was performed intraoperatively. The biopsy
results were consistent with fibrous dysplasia. The patient's visual complaints
were related to multiple sclerosis after further evaluation, and subsequently
improved with treatment of the multiple sclerosis. At 3 years, the lesion
has been stable without change in size, and the patient remains asymptomatic
with regard to the lesion.
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Fibrous dysplasia within the skull base is frequently complicated by
aneurysmal bone cyst formation (Figure 2, Figure 5, Figure 6, and Figure 9).20 In the present series, bone cyst formation occurred
in 5 patients (24%). Clinically, this entity can often be confused with a
malignant lesion. This was the case with a patient in this study with a large
cystic lesion expanding into the middle cranial fossa who underwent a middle
fossa approach for diagnosis (Figure 6).
Although the development of aneurysmal bone cysts is a well-known occurrence
throughout the skeletal system, they have not been frequently described within
the skull base. As this study demonstrates, an aneurysmal bone cyst is a lesion
that is frequently seen in patients who have fibrous dysplasia of the skull
base. However, in contrast to its formation in the long bones throughout the
body, because of the confined space within the base of the skull, their expansion
can quickly lead to clinical symptoms, with increased morbidity.20
All 5 patients in this series with aneurysmal bone cyst formation required
surgery because of the expansile nature of the lesion. Fibrous dysplasia is
thought to be particularly susceptible to bone cyst formation because of the
vascularity of the lesion.20, 28
Radiographically, the lesions appear as expansile cystic lesions with a bony
shell, with either a fluid or soft tissue–appearing center.
Pathologically, fibrous dysplasia lesions are characterized by expansion
of cortical bone with gradual replacement by fibrous tissue that is firm,
rubbery, and gritty. Lesions within the skull tend to have a firmer consistency
than their counterparts in the long bones of the body due to a greater amount
of bony spicules.10 Cystic lesions can often
be filled with an amber fluid and can occasionally be vascular. Microscopically,
the lesion is readily identifiable, with an irregular trabeculae of woven
bone intermixed with a connective tissue stroma (Figure 10). Lesions will vary in the amount and distribution of
bone and in the cellularity and vascularity of the fibrous stroma.
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Figure 10. Histopathologic section of a
typical fibrous dysplasia lesion (hematoxylin-eosin, original magnification
x40). There is a pattern of irregular woven bone intermixed with a connective
tissue stroma.
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Within the skull base, a known variant of this classic pathologic picture
is a distinct histologic pattern of "cementicles," small bony spicules resembling
pieces of a puzzle, interspersed throughout the lesion. This is a variant
that is unique to the skull and is not found in lesions occurring in the long
bones of the body. These lesions are characterized by a loose fibrous background
and darkly stained cemented ossicles surrounded by reactive bone (Figure 11). Although these lesions, referred
to within the literature with such diverse terms as ossifying
fibroma and cementifying fibroma, present
with subtle clinical, radiographic, and histologic differences,29
we have traditionally regarded these differences as slight variations of the
same underlying pathologic process.
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Figure 11. A pathologic variant of fibrous
dysplasia characterized by a distinct histologic pattern of "cementicles,"
small bony spicules resembling pieces of a puzzle, interspersed throughout
the lesion (hematoxylin-eosin, original magnification x40).
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Although some pharmacologic agents exist for treating patients with
osteodystrophies, their effects have been limited in patients with fibrous
dysplasia. These medications include bisphosphonates, which inhibit osteoclastic
bone resorption.30 Other medications, such
as aromatase inhibitors (ie, testolactone) and tamoxifen citrate have proven
successful in the treatment of precocious puberty in patients with McCune-Albright
syndrome.31
In the absence of curative medicine for fibrous dysplasia, surgery remains
the mainstay of therapy. However, it must be remembered that fibrous dysplasia
is a benign process, and therapy should be guided by the patient's clinical
presentation. As such, lesions discovered incidentally and that are asymptomatic
may be followed conservatively by serial CT or MRI scans. More often, however,
the surgeon is faced with a lesion and without a diagnosis. If a lesion cannot
be readily classified by radiologic studies, open biopsy and surgical excision
are warranted. If a fibrous dysplasia lesion is suspected and surgery is determined
to be the most appropriate course of action, complete extirpation of the lesion
may not be required, particularly if important or vital structures (such as
cranial nerves or the carotid artery) are placed at risk. In this scenario,
subtotal resection with close follow-up is often adequate to control the clinical
symptoms. Radiation therapy is ineffective and contraindicated because of
the possibility of malignant transformation.8, 24
Lesions involving the sinuses can range from a small isolated lesion
of the ethmoid or maxilla to massive lesions causing frontal lobe compression.
Most lesions can be approached anteriorly, either endoscopically32
or via a more traditional transfacial approach.33-34
Small, isolated lesions of the sinuses, such as in patient 3 in this study,
who presented with an isolated lesion of the ethmoid, can be approached endoscopically.
Because symptoms are mainly due to compression of adjacent structures, marsupialization
and subtotal resection are often adequate to control symptoms in these limited
cases. The diagnosis is often not made until after the operation, however,
when the pathology report is reviewed. If a subtotal resection was performed
in these cases, patients can often be watched conservatively with serial scans
and with a planned return to the operating room should the patien's symptoms
recur.
Fibrous dysplasia involving the temporal bones has been well documented
in the literature.8, 10, 24, 35-38
With temporal bone involvement, the primary indications for surgery are canal
stenosis leading to hearing loss, as seen in 2 patients in this study, and
the presence of a cholesteatoma behind a stenotic external auditory canal.8, 24 During canalplasty, diseased bone
is typically spongy, soft, and easily shelled out by curette. Recurrence is
likely, however, with approximately half of all patients requiring 2 or more
operations. Placement of a simple Silastic stent can often assist with keeping
a canal open between outpatient curettage treatments, as was done in both
patients in this study. Another option to prevent restenosis of the external
canal is skin grafting. Sensorineural hearing loss secondary to impingement
on the acoustic nerve within the internal auditory canal is a well-described
feature in advanced cases. There have been cases of reversal of the loss after
decompression of the internal auditory canal.39
Other lesions of the skull base, such as of the parietal or occipital
bones, should also be treated according to the patient's presentation. Nonsymptomatic
lesions that are not cosmetically disfiguring can be watched conservatively.
As solitary lesions expand and compress intracranial structures, such as with
aneurysmal bone cyst formation, they may require operative intervention. In
patients with widespread skull base involvement, where the occipital and parietal
skull is involved, the diagnosis is clear and lesions can often be followed
conservatively for years. A common scenario, however, as was seen in one patient
in this study (patient 12 in Table 2),
is where a patient presents with a solitary unknown lesion and undergoes an
operative biopsy and excision. Although this patient underwent complete excision
of the lesion, even if a subtotal resection has been performed, a patient
can usually be conservatively followed for years with serial scans and close
attention to recurrence of symptoms.
In summary, fibrous dysplasia involving the skull base can present in
myriad ways. Modern imaging modalities and histopathologic analysis have made
diagnosis relatively straightforward. Surgery, particularly in a challenging
region such as the skull base, should be reserved for patients with functional
impairment or a cosmetic deformity. Because of the benign nature of the condition,
the surgery itself should be relatively conservative, with the primary goal
being preservation of existing function.
AUTHOR INFORMATION
Accepted for publication May 17, 2001.
Presented in part at the International Skull Base Congress, Chicago,
Ill, May 1999.
Corresponding author: Lawrence R. Lustig, MD, Department of Otolaryngology–Head
and Neck Surgery, The Johns Hopkins University, JHOC Sixth Floor, 601 N Caroline
St, Baltimore, MD 21287-0910 (e-mail: llustig{at}bme.jhu.edu).
From the Departments of Otolaryngology–Head and Neck Surgery
(Drs Lustig, Holliday, and Nager) and Pathology (Mr McCarthy), The Johns Hopkins
University, Baltimore, Md.
REFERENCES
| |
1. von Recklinghausen F. Die Fibrose oder deformierende Ostitis, die Osteomalacie
und die osteoplastische Carcinose in ihren gegenseitigen Beziehungen. Vol 13. Berlin, Germany; 1891.
2. Wells C. Polyostotic fibrous dysplasia in a 7th century Anglo-Saxon. Br J Radiol. 1963;36:925-926.
3. Gregg J, Reed A. Monostotic fibrous dysplasia in the temporal bone: a late prehistoric
occurrence. Am J Phys Anthropol. 1980;52:587-593.
FULL TEXT
|
ISI
| PUBMED
4. McCune D, Bruch H. Osteodystrophia fibrosa: report of a case in which the condition was
combined with precocious puberty, multiple pigmentation of the skin and hyperthyroidism. AJDC. 1937;52:745-748.
5. Albright F, Butler M, Hamptom A, Smith P. Syndrome characterized by osteitis fibrosa disseminata, areas of pigmentation
and endocrine dysfunction with precocious puberty in females. N Engl J Med. 1937;216:727-746.
ISI
6. Nager G. Fibrous dysplasia. In: Pathology of the Ear and Temporal Bone.
Baltimore, Md: Williams & Wilkins; 1993:1082-1148.
7. Lichtenstein L. Polyostotic fibrous dysplasia. Arch Surg. 1938;36:874-898.
FREE FULL TEXT
8. Nager GT, Holliday MJ. Fibrous dysplasia of the temporal bone: update with case reports. Ann Otol Rhinol Laryngol. 1984;93:630-633.
ISI
| PUBMED
9. Schlumberger H. Fibrous dysplasia of single bones (monostotic fibrous dysplasia). Mil Surg. 1946;99:504-527.
10. Nager G, Kennedy D, Kopstein E. Fibrous dysplasia: a review of the literature and its manifestations
in the temporal bone. Ann Otol Rhinol Laryngol (Suppl). 1982;92:1-52.
11. Lichtenstein L, Jaffe H. Fibrous dysplasia of bone. Arch Pathol. 1942;33:777-816.
ISI
12. Changus G. Osteoblastic hyperplasia of bone: a histochemical appraisal of fibrous
dysplasia of bone. Cancer. 1957;10:1157-1161.
13. Aegerter E, Kirkpatrick J. Orthopedic Diseases. 3rd ed. Philadelphia, Pa: WB Saunders Co; 1968.
14. Reed R. Fibrous dysplasia of bone. Arch Pathol. 1963;75:480-495.
ISI
| PUBMED
15. Lee P, Van Dop C, Migeon C. McCune-Albright syndrome: long-term follow-up. JAMA. 1986;256:2980-2984.
FREE FULL TEXT
16. Warner DR, Weinstein LS. A mutation in the heterotrimeric stimulatory guanine nucleotide binding
protein alpha-subunit with impaired receptor-mediated activation because of
elevated GTPase activity. Proc Natl Acad Sci U S A. 1999;96:4268-4272.
FREE FULL TEXT
17. Warner DR, Weng G, Yu S, Matalon R, Weinstein LS. A novel mutation in the switch 3 region of Gs in
a patient with Albright hereditary osteodystrophy impairs GDP binding and
receptor activation. J Biol Chem. 1998;273:23976-23983.
FREE FULL TEXT
18. Riminucci M, Fisher LW, Majolagbe A, et al. A novel GNAS1 mutation, R201G, in McCune-Albright syndrome. J Bone Miner Res. 1999;14:1987-1989.
FULL TEXT
|
ISI
| PUBMED
19. Cohen M, Howell R. Etiology of fibrous dysplasia and McCune-Albright syndrome. Int J Oral Maxillofac Surg. 1999;28:366-371.
FULL TEXT
|
ISI
| PUBMED
20. Wojno K, McCarthy E. Fibro-osseous lesions of the face and skull with aneurysmal bone cyst
formation. Skeletal Radiol. 1994;23:15-18.
ISI
| PUBMED
21. Spjut H, Dorfman H, Fechner R, Ackner L. Tumors of Bone and Cartilage: Atlas of Tumor Pathology. Washington, DC: Armed Forces Insitute of Pathology; 1970.
22. Windolz F. Cranial manifestations of fibrous dysplasia of bone. AJR Am J Roentgenol. 1947;58:51-63.
ISI
23. Van Tillburg W. Fibrous dysplasia. In: Vinken P, Bruyn G, eds. Handbook of Clinical
Neurology. Vol 14. Amsterdam, the Netherlands: North Holland Publishing
Co; 1972:163-212.
24. Lambert PR, Brackmann DE. Fibrous dysplasia of the temporal bone: the use of computerized tomography. Otolaryngol Head Neck Surg. 1984;92:461-467.
ISI
| PUBMED
25. d'Archambeau O, Parizel PM, Koekelkoren E, Van de Heyning P, De Schepper AM. CT diagnosis and differential diagnosis of otodystrophic lesions of
the temporal bone. Eur J Radiol. 1990;11:22-30.
FULL TEXT
|
ISI
| PUBMED
26. Tehranzadeh J, Fung Y, Donohue M, Anavim A, Pribram HW. Computed tomography of Paget disease of the skull versus fibrous dysplasia. Skeletal Radiol. 1998;27:664-672.
FULL TEXT
|
ISI
| PUBMED
27. Casselman JW, De Jonge I, Neyt L, De Clercq C, D'Hont G. MRI in craniofacial fibrous dysplasia. Neuroradiology. 1993;35:234-237.
FULL TEXT
|
ISI
| PUBMED
28. Boysen M, Olving J, Vatne K, Koppang H. Fibro-osseous lesions of the cranio-facial bones. J Laryngol Otol. 1979;93:793-799.
ISI
| PUBMED
29. Eversol LR, Sabes WR, Rovin S. Fibrous dysplasia: a nosologic problem in the diagnosis of fibro-osseous
lesions of the jaws. J Oral Pathol. 1972;1:189-220.
FULL TEXT
| PUBMED
30. Devogelaer J. Treatment of bone diseases with bisphosphonates, excluding osteoporosis. Curr Opin Rheumatol. 2000;12:331-335.
FULL TEXT
|
ISI
| PUBMED
31. Eugster E, Shankar R, Feezle L, Pescovitz O. Tamoxifen treatment of progressive precocious puberty in a patient
with McCune Albright syndrome. J Pediatr Endocrinol Metab. 1999;12:681-686.
ISI
| PUBMED
32. Ikeda K, Suzuki H, Oshima T, Shimomura A, Nakabayashi S, Takasaka T. Endonasal endoscopic management in fibrous dysplasia of the paranasal
sinuses. Am J Otolaryngol. 1997;18:415-418.
FULL TEXT
|
ISI
| PUBMED
33. Ragab MA, Mathog RH. Surgery of massive fibrous dysplasia and osteoma of the midface. Head Neck Surg. 1987;9:202-210.
ISI
| PUBMED
34. Ferguson BJ. Fibrous dysplasia of the paranasal sinuses. Am J Otolaryngol. 1994;15:227-230.
FULL TEXT
|
ISI
| PUBMED
35. Reddy KT, Vinayak BC, Jefferis AF, Grieve DV. Fibrous dysplasia of the temporal bone. Ann Otol Rhinol Laryngol. 1994;103:74-76.
ISI
| PUBMED
36. Sataloff RT, Graham MD, Roberts BR. Middle ear surgery in fibrous dysplasia of the temporal bone. Am J Otol. 1985;6:153-156.
ISI
| PUBMED
37. Yagoda MR, Selesnick SH. Temporal bone fibrous dysplasia and cholesteatoma leading to the development
of a parapharyngeal abscess. J Laryngol Otol. 1994;108:51-53.
ISI
| PUBMED
38. Megerian CA, Sofferman RA, McKenna MJ, Eavey RD, Nadol JB Jr. Fibrous dysplasia of the temporal bone: ten new cases demonstrating
the spectrum of otologic sequelae. Am J Otol. 1995;16:408-419.
ISI
| PUBMED
39. Morrissey DD, Talbot JM, Schleuning II AJ. Fibrous dysplasia of the temporal bone: reversal of sensorineural hearing
loss after decompression of the internal auditory canal. Laryngoscope. 1997;107:1336-1340.
FULL TEXT
|
ISI
| PUBMED
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