Monostotic Fibrous Dysplasia with or without Spinal Hemangioma?

History

The patient is a 17-year-old female who presented with upper back pain.

Examination

The patient's age corresponds to her height, development, and menstrual cycle. A few café au-lait spots appear on her back and chest. Breast shape and size is asymmetrical. Her body temperature is persistently sub-febrile between 37.1 to 37.2-degrees Celsius (98.78-98.96-degrees Fahrenheit). No neurological dysfunction.

Prior Treatment

Non-steroidal anti-inflammatory drugs (NSAIDs)

Images

Figure 1. Café au-lait spots on upper back. Image courtesy of Iqbal Shabir Khan, MD, and SpineUniverse.com.

Plain x-rays revealed no irregularities except subchondral sclerosis of the vertebral endplates.

Figure 2A: A sagittal thoracic CT scan shows a lytic lesion at T8. Diagnosed as possible hemangioma prior to biopsy? Image courtesy of Iqbal Shabir Khan, MD, and SpineUniverse.com.

Figure 2B: Anteroposterior CT demonstrates lytic lesion and spondylitic impression at T8 with subchondral thickening. Image courtesy of Iqbal Shabir Khan, MD, and SpineUniverse.com.

Figure 2C. Axial CT of T8 vertebrae with right-half coin-shaped hollow lesion. Image courtesy of Iqbal Shabir Khan, MD, and SpineUniverse.com.

Figure 3: Axial bone scintigraphy shows hyper re-uptake of the radionuclide material at T8 focal lesion with no other bony abnormality. Image courtesy of Iqbal Shabir Khan, MD, and SpineUniverse.com.

Figure 4: T1-T10 is noted (between the arrows). MR imaging demonstrates degenerative-dystrophic changes of the thoracic vertebrae with Schmorl's nodes at T11 and T12. Image courtesy of Iqbal Shabir Khan, MD, and SpineUniverse.com.

Diagnosis

Transpedicular biopsy of the lesion at T8 showed monostotic fibrous dysplasia.

Selected Treatment

This patient was first clinically observed and was put on NSAIDs with biphosponate therapy. After the confirmatory biopsy, which revealed that the lesion was fibrous dysplasia, we performed lesion extirpation, anterior fusion with cortical bone grafting and posterior stabilization from T-6 to T-10. The patient remained hospitalized 10 days after surgery.

Outcome

On her next follow-up (30 days after discharge), the patient was free of pain and had regained her normal function.

Case Discussion

Jason M. Highsmith, MD

Neurosurgeon

Charleston Brain and Spine

While the name Fibrous Dysplasia (FD) is rather innocuous sounding, these lesions are typically treated as benign tumors with surgical resection. While there is no consensus for management, this case demonstrates effective pain relief after surgery as reported in similar cases.^1-3

FD accounts for 5% of benign bone tumors.⁴ It is a tumor-like growth of immature, irregular woven bone amidst a fibrous, whirled stroma. The "Chinese letters" or "alphabet soup" appearance of this stroma histologically is pathognomonic.

Most patients present as young people with chronic back pain; a history that suggests a neoplastic process. Some patients may present with neurologic deficit or radiculopathy, typically from fracture/dislocation of the affected vertebrae.

While more common in long bones, such as the femur and tibia, lesions can occur anywhere along the neuroaxis or even in the ribs. Treatments have included all of the treatment options listed, as well as radiotherapy. A gross total excision of the lesion combined with anterior-posterior fixation and fusion should be more than adequate to address this pathology long-term.

References
1. Ould Slimane M, Foulongne E, Derrey S, Fréger P, Proust F. Polyostotic fibrous dysplasia of the thoracic spine. A case study and review of the literature. Neurochirurgie. 2009 Dec; 55(6):595-9. Epub 2009 Jul 4.

2. Arazi M, Guney O, Ozdemir M, Uluoglu O, Uzum N. Monostotic fibrous dysplasia of the thoracic spine: clinopathological description and follow up. Case report. J Neurosurg. 2004 Apr;100(4 Suppl Spine):378-81.

3. Przybylski GJ, Pollack IF, Ward WT. Monostotic fibrous dysplasia of the thoracic spine. A case report. Spine (Philadelphia, PA 1976). 1996 Apr 1; 21(7):860-5.

4. DiCaprio M. R., Enneking W. F. Fibrous Dysplasia. Pathophysiology, Evaluation, and Treatment. J Bone Joint Surg Am. 2005;87:1848-1864.