CASE OF THE WEEK – “A rare case of Fibrous Dysplasia of the Clivus skull bone ” by Dr ShekharShikare, HOD & Consultant, Nuclear Medicine, NMC Royal Hospital Sharjah

CASE OF THE WEEK – “A rare case of Fibrous Dysplasia of the Clivus skull bone ” by Dr ShekharShikare, HOD & Consultant, Nuclear Medicine, NMC Royal Hospital Sharjah

A rare case of Fibrous Dysplasia of the Clivus skull bone

The incremental value of Radionuclide Bone Scintigraphy in fibrous dysplasia of bone

Introduction

Fibrous dysplasia (FD) is a developmental disorder caused by abnormal proliferation of fibroblasts resulting in replacement of normal cancellous bone by structurally weak, immature osseous tissue. This process of unknown etiology, which mainly affects the younger population, may be monostotic, polyostotic or associated with McCune-Albright syndrome. The monostotic FD usually involves the temporal bone, orbit, mandible, and paranasal sinuses in craniofacial region.

Fibrous dysplasia (FD) of the isolated clivus, first described by Lichetenstein in 1938, is a very rare developmental, non heridtory disorder by abnormal proliferation of maturation of fibroblast resulting in replacement of the mature bone by weak and immature bone .

FD might be confused with other disease involving the clivus, for which a more aggressive surgical approach is generally advised. Furthermore, with advancement and wide use of computed tomography (CT) and Magnetic resonance (MR) imaging, many of clival FD can be detected incidentally. The awareness of and differentiating it from other skull base lesions is central in managing the patients with FD in the clivus.

Case

33 years old lady with history of increased frequency of sharp headache attacks up to four times per month mainly in left temporal side associated with nausea and mild dizziness. Sometime with prior vision disturbance but as well vision disturbances without following headache since six month have been further clarified.

X-ray skull showed increased sclerosis in the region of clivus, MRI brain with contrast revealed a contrast enhancing mass at left clivus, which likely the reason for her complaints and a white matter lesion in left frontal on unknown origin.

 

CT Scan Images

The clivus skull bone shows an expansile sclerotic appearance lesion with ground glass density pattern & scattered areas of radiolucency. There is no cortical destruction or soft tissue component, boundaries of the sphenoid sinus, foramen magnum and adjacent bone of the skull base are uninvolved favors fibrous dysplasia.

A rare case of Fibrous Dysplasia of the Clivus skull bone  by Dr Shekar Shikare, HOD & Consultant, Nuclear Medicine, NMC Royal Hospital Sharjah A rare case of Fibrous Dysplasia of the Clivus skull bone  by Dr Shekar Shikare, HOD & Consultant, Nuclear Medicine, NMC Royal Hospital Sharjah A rare case of Fibrous Dysplasia of the Clivus skull bone  by Dr Shekar Shikare, HOD & Consultant, Nuclear Medicine, NMC Royal Hospital Sharjah A rare case of Fibrous Dysplasia of the Clivus skull bone  by Dr Shekar Shikare, HOD & Consultant, Nuclear Medicine, NMC Royal Hospital Sharjah A rare case of Fibrous Dysplasia of the Clivus skull bone  by Dr Shekar Shikare, HOD & Consultant, Nuclear Medicine, NMC Royal Hospital Sharjah

CT SCAN images of skull (figure 1 to 5)

Referred for 99mTc MDP whole body bone and SPECT CT scintigraphy to evaluate if it is MONOSTOTIC or POLYSTOTIC fibrous dysplasia.

 

99mTc- MDP WHOLE BODY BONE AND SPECT-CT FUSED IMAGES OF SKULL confirms that involvement is confined to the clivus without evidence of disseminated disease. There is intensely increased uptake in CLIVUS BONE OF THE SKULL. ( figure 1 to 5).

A rare case of Fibrous Dysplasia of the Clivus skull bone  by Dr Shekar Shikare, HOD & Consultant, Nuclear Medicine, NMC Royal Hospital Sharjah A rare case of Fibrous Dysplasia of the Clivus skull bone  by Dr Shekar Shikare, HOD & Consultant, Nuclear Medicine, NMC Royal Hospital Sharjah

99mTc MDP whole body and spot images of skull bones (figure 1 & 2)

A rare case of Fibrous Dysplasia of the Clivus skull bone  by Dr Shekar Shikare, HOD & Consultant, Nuclear Medicine, NMC Royal Hospital Sharjah A rare case of Fibrous Dysplasia of the Clivus skull bone  by Dr Shekar Shikare, HOD & Consultant, Nuclear Medicine, NMC Royal Hospital Sharjah

99mTc MDP SPECT-CT images of skull bones (figure 3 & 4)

A rare case of Fibrous Dysplasia of the Clivus skull bone  by Dr Shekar Shikare, HOD & Consultant, Nuclear Medicine, NMC Royal Hospital Sharjah

Discussion

In 70% of cases FD affects a single bone, Monostotic FD, with the frontal, sphenoid, ethmoid, orbit, zygoma, maxilla, mandible, and temporal bones being the common sites affected in craniofacial bones. However, monostotic fibrous dysplasia of the clivus is extremely rare. In 30% of cases FD is polyostotic affecting several bones, where the craniofacial bones are mainly affected.

FD of the Clivus can be present with headache but in severe cases cranial nerve involvement may occur.

literature stated the diagnosis is generally clear after a proper radiological and scintigraphic workup

CT SCAN skull images shows the characteristic appearance of thinning of the cortical bone, expansion of the affected area with “ground glass” density.expansion of the involved bone with intact cortical outline, along with a varied degree of contrast enhancement within the lesion and not along the adjacent thickened dura.

Radionuclide bone scans are of certain value in the diagnosis of FD and useful in determining the extent of the skeletal involvement especially in polyostotic lesions. The diagnostic specificity of FD with radionuclide bone scanning can be improved in association with other imaging modalities such as X-rays. CT scan with contrast, SPECT-CT enhances sensitivity for lesions detection over planar bone scintigraphy. In addition to improve anatomic localization of scintigraphic findings, this equipment offers the opportunity to add true diagnostic information derived from CT imaging.

However, biopsy might be needed if the diagnosis is doubtful or malignant transformation is suspected.

Case

28 years old gentleman with history of fall on right out stretched hand. Complaining of pain and swelling in right scaphoidal region. X-rays of hand- unremarkable

99mTcMDP WHOLE BODY, SPOT & SPECT CT FUSED IMAGES OF THE HAND BONE

 

BLOOD POOL IMAGES OF HAND
Focal area of abnormal pooling of tracer seen in right wrist region medially(as compared to opposite).

 

SPOT AND SPECT CT FUSED IMAGES OF HAND
It shows focal area of abnormally increased tracer uptakes in right scaphoidal bone (mid portion approximately and better appreciated in SPECT-CT fused images).

 

FOCALLY ACTIVE (HOT SPOT) ABNORMALITY SEEN INVOLVING MID PORTION OF THE SCAPHOIDAL BONE OF RIGHT WRIST PERSISTENT WITH FRACTURE.

A rare case of Fibrous Dysplasia of the Clivus skull bone  by Dr Shekar Shikare, HOD & Consultant, Nuclear Medicine, NMC Royal Hospital Sharjah A rare case of Fibrous Dysplasia of the Clivus skull bone  by Dr Shekar Shikare, HOD & Consultant, Nuclear Medicine, NMC Royal Hospital Sharjah

IMAGES OF HANDS

A rare case of Fibrous Dysplasia of the Clivus skull bone  by Dr Shekar Shikare, HOD & Consultant, Nuclear Medicine, NMC Royal Hospital Sharjah A rare case of Fibrous Dysplasia of the Clivus skull bone  by Dr Shekar Shikare, HOD & Consultant, Nuclear Medicine, NMC Royal Hospital Sharjah A rare case of Fibrous Dysplasia of the Clivus skull bone  by Dr Shekar Shikare, HOD & Consultant, Nuclear Medicine, NMC Royal Hospital Sharjah

Figure 3,4 & 5 - BONE SPECT CT FUSED IMAGES OF THE HANDS
RIGHT WRIST-SCAPHOIDAL BONE FRACTURE.

Occult spinal fractures and sacral insufficiency fractures occur in a variety of clinicalcircum stances.Older osteoporotic individuals are at particular risk for vertebral body fractures. Such fractures may produce only a minimal loss of vertebral body height that is difficult to appreciate on conventional radiographic examinations. Fractures of the sacrum also are notoriously difficult to appreciate radiographically. The osteoporotic sacrum is prone to a characteristictype of insufficiency fracturewith fracture lines running vertically through the left and right sides of the sacrum just medial to the sacroiliac joints in additionto a fracture crossing the mid-sacrumtransversely just below the inferior margins of the sacroiliac joints.

 

Such osteoporotic fractures of the spine and sacrum infrequently require specific orthopedic treatment. Nonetheless, establishing a cause for pain in these patients whose radiographics show only osteoporosis is a significant diagnostic problem.Treatment is usually directed toward pain relief and medically treatable causes for the underlying osteoporosis. Bone scanning also has a significant role to play in pediatrics for patients with continued unexplained pain following trauma.

 

The ability to survey the entire skeleton and identify sites of non accidental trauma is a particular strength of bone scanning . Total body radionucide bone scanning also is useful for imaging adults who have suffered extensive trauma. The full extent of injuries produced by motor vehicle accidents, such as sternal and multiple rib fractures, may be over looked initially in patients with multiple sites of skeletal trauma and severe injury to other organs. Impaction of the anterior chest wall on the steering wheel during a motor vehicle accident often produces a horizontal transverse fracture throughthe mid sternum along with multiple frac tures of adjacent anterior ribs lying one above the other.