Tumoral calcinosis: a case report with an electron microscopic study

A 68-year-old woman developed large subcutaneous masses on her abdomen and thighs after a bruise sustained in a traffic accident. She had severe pain when sitting up straight. Histological examination revealed calcified tissu es in the entire dermis of the injured areas. On electron microscopy, cryst alline materials were observed in the dermis, which seemed to be formed by the deposition of hydroxyapatite on unusual proteoglycan. In a vessel wall, a thick, layered basement membrane was observed. This suggests that vascul ar injury and subsequent hypoxia play a role in the process of calcinosis. We performed a partial resection with good results in alleviating the patie nt's pain.