Oncogenic osteomalacia induced by schwannoma in a patient with neurofibromatosis.

A 62-year-old woman known to be suffering from Von Recklinghausen disease and osteomalacia was operated on for a pelvic mass. Pathological examination of the excised tumor showed it to be a schwannoma and this tumor was considered to be responsible for the osteomalacia. The return of previously abnormal laboratory data to normal values and the impressive clinical and subjective improvement further support the assumption that the excised schwannoma was responsible for the pathology observed in this patient.