Oncogenic osteomalacia cured by removal of an organized hematoma

To describe a patient with oncogenic osteomalacia whose symptoms were rapidly resolved after surgical removal of an organized hematoma of the hip.

A case report is presented, including clinical and laboratory findings. The relevant literature is reviewed, and the current understanding of oncogenic osteomalacia is summarized.

In September 1996, a 44-year-old black woman presented with a 2-year history of bone pain, progressive muscle weakness, depression, osteomalacia, and hypophosphatemia. Her condition did not improve with use of calcitriol and phosphate replacement. During the previous year, her serum phosphorus levels were low, ranging from 1.0 to 2.2 mg/dL, and the levels of serum 1,25-dihydroxyvitamin D [1,25-(OH)2D] were very low, ranging from <5 to 19.4 pg/mL (normal, 15 to 60). The serum 25-hydroxyvitamin D levels were low, ranging from 8 to 14 ng/mL (normal, 9 to 52). The higher values were noted after she had received large doses of phosphate, 1,25-(OH)2D, and vitamin D. During the previous year, her serum alkaline phosphatase levels were high, ranging from 253 to 314 U/L; serum calcium and parathyroid hormone levels were normal. The abnormalities on physical examination were obesity and a 10- by 10-cm firm, poorly demarcated mass superior to the left greater trochanter. A computed tomographic scan of this region showed a water-density fluid collection in the left buttock measuring 7.8 by 7.8 cm, consistent with a chronic hematoma. The mass was resected, and histopathologic examination revealed features of an organized hematoma with areas of myxoid changes and cartilaginous metaplasia. Postoperatively, the patient's strength improved, and the levels of serum phosphorus and 1,25-(OH)2D became supranormal.

The symptoms and laboratory abnormalities of this patient with oncogenic osteomalacia promptly resolved after resection of an organized hematoma of the left hip.