Spinal cord compression by heterotopic ossification associated with pseudohypoparathyroidism.

This report describes a 37-year-old man presenting with a gait disturbance due to spastic paraparesis. Physical findings showed typical features of Albright's hereditary osteodystrophy, including short stature, obesity, brachydactyly and dental hypoplasia. He was diagnosed as having pseudohypoparathyroidism type Ia, on the basis of his hypocalcaemia, hyperphosphataemia, increased plasma level of parathyroid hormone (PTH), and the unresponsiveness to exogenous PTH loading of his urinary excretion of both nephrogenous cyclic adenosine monophosphate and phosphate.

The presence of siderosomes in synovioblasts (B cells) of chronic spontaneous hemarthrosis. Histologic, electron microscopic, and roentgenographic electron microanalysis studies of three cases.

The synovium of three patients with chronic spontaneous hemarthrosis was examined by light and electron microscopy and roentgenographic electron microanalysis. The synovium showed hyperplastic villous processes with proliferation of synovioblasts (B cells) and synovial macrophages (A cells). Erythrophagocytosis was observed in synovial macrophages but not in synovioblasts.