[A case of retroperitoneal schwannoma associated with primary hyperparathyroidism].

A rare case of benign retroperitoneal schwannoma in a 47-year-old female is reported. She was initially diagnosed to have an adrenal tumor at the Prefectural Cancer Center Hospital and was subsequently admitted to this hospital. When she was admitted, she was diagnosed as undergoing a hypercalcemic crisis (s-Ca 9.2mEq/l). Serum intact-PTH was elevated, but urine cyclic-AMP and % TRP were almost normal. Gd-DTPA enhanced T1 weighted MRI showed a hyperintensity area between the trachea and the thyroid. A parathyroid tumor and a retroperitoneal tumor were excised completely. The final pathological diagnoses were determined to be a parathyroidal adenoma and a retroperitoneal Schwannoma. After a 6-month follow-up period no recurrence and no electrolytic imbalance were detected and the patient presently displays no further symptoms.