Vertebral involvement in hyperphosphatemic tumoral calcinosis.

Hyperphosphatemic tumoral calcinosis (HTC) is an inherited metabolic disorder characterized by calcified soft tissue masses and hyperphosphatemia. Besides these typical features, a number of less common manifestations have been reported, all of them related to pathologic calcification of various tissues. We have investigated the case of a woman with hyperphosphatemia, recurrent episodes of lumbar pain, and a positive familial history of HTC. A bone scan showed markedly increased uptake in the lower lumbar spine. Magnetic resonance imaging showed pathological changes in L5 compatible with an inflammatory reaction and not suggestive of neoplastic process. There was no evidence of infection, trauma, malignancy, or other disease that could cause the lesion. We treated the patient with analgesics and NSAIDs and the pain remitted over a period of 1 week. In a follow-up magnetic resonance imaging 7 months later, the L5 lesion had disappeared completely. A computed tomography scan analysis with a bone window showed a sclerotic area at the L5 vertebral body. We believe that this patient was affected by the syndrome of HTC and that the inflammatory phenomena found in L5 are a manifestation of this disease.