Spinal polyostotic fibrous dysplasia in two adults: Does only biopsy unravel the mystery?
A 27 year old man became symptomatic following repeated falls on a slippery surface with chronic low backache and neck pain for one year. He also noticed bone pains and the severity progressed over six months to an extent that he had gross limitations of his daily activities, had to be bed bound and developed chronic insomnia. He didn’t have arthralgia, deformity of the joints/bones or systemic symptoms. He weighed 69 kgs for a height of 170 cm (he reported his height was 173 cm at the age of 18 years). He had tenderness at lower thoracic and lumbar spine. He had no deformity. His general and systemic examination was normal.\nInvestigations revealed a haemoglobin of 14.2 g/dL (14 ± 2.5), total leucocyte count 7,500/cu.mm (4,000-11,000), platelets 1,87,000/cu.mm (1,50,000-4,50,000), erythrocyte sedimentation rate 5mm fall at first hour (0-10), fasting blood glucose 97mg/dL (70-100), blood urea nitrogen 12 mg/dL (7-19), creatinine 0.8mg/dL (0.5-1.6), sodium 140 mEq/L (135-149), potassium 4.1mEq/L (3.5-5.0), bilirubin 0.9mg/dL (<1), aspartate trasaminase 85 U/L (<40), alanine trasaminase 78 U/L (<40), alkaline phosphatase 354 U/L (<250), protein 7.9 g/dL, albumin 4.2 g/dL, calcium 8.6 mg/dL (8.5-10.5), phosphorous 3.8 mg/dL (2.5-4.5), lactate dehydrogenase 811 U/L (230-460) and uric acid 7.2 mg/dL (2-6). CRP was 6mg/L (<6), HLA-B 27 was negative. X-ray of spine showed multiple lytic lesions with collapse of 8th dorsal vertebra and ill-defined radiolucencies in both pubic rami and ischium []. Computed tomography of spine showed extensive involvement of spine, sternum, pelvis, heads of humerus and femur []. MRI spine showed extensive marrow infiltration of spine and pelvic bone and collapse of C3, D1 and D8 vertebrae []. He was evaluated for multiple myeloma with serum electrophoresis which was negative for “M” band, light chain assay was negative and bone marrow aspiration was dry and bone marrow biopsy showed extensive fibrosis (?secondary). Bone scan showed increased uptake in involved areas []. FDG-PET confirmed increased metabolic activity in above area and was suggestive of malignancy with highest SUV of 7.6 in sacrum []. Parathormone (PTH) was 13 pg/mL (10-65), 25(OH) vitamin-D was 65 ng/mL (30-150) and endocrinal evaluations (thyroid, adrenal and pituitary function tests) were normal. Oncological markers including PSA, CEA and CA 19.9 were normal. BMD z-score at spine, hip and forearm were -2.6, -0.8 and 0.5 respectively. With the suspicion of lymphoma, infective etiology, or secondary a CT guided fine needle aspiration was done; but was inconclusive. To obtain tissue diagnosis an open biopsy of left sacral ala and a repeat bone marrow aspiration and biopsy from matched involved area from bone scan and CT scan at iliac spine was performed. Histopathology of bone biopsy was consistent with fibrous dysplasia []. Severity of fibrous dysplasia as interpreted by bone scan[] was 11%. He was started on intravenous zoledronic acid 4 mg quarterly, calcium and vitamin D supplements. Opioid analgesics were required to control his bone pain.