Schwannoma of the adrenal gland

Visceral schwannomas are extremely rare and are usually discovered incidentally on USG/CT-Scan. Primary schwannomas of the adrenal gland are extremely uncommon. It has been theorized that they originate from Schwann cells that insulate the nerve fibers innervating the adrenal medulla. Histopathological examination coupled with immunohistochemistry provides the definitive diagnosis. A 55 year old normotensive female presented with pain in the right loin since 5 months. Her renal parameters were normal. Contrast enhanced computed tomography of abdomen showed a well delineated 6.5 x 5cms mass at upper pole of her right kidney. 24-hour urinary metanephrine was slightly elevated (3.07mg/24hrs). A decline in Serum cortisol levels was observed following a dexamethasone suppression test (18.89nmol/l). Histopathological examination revealed a spindle cell tumor. Immunohistochemistry showed strong and diffuse positive staining for S-100 with negative expression for CD-117, desmin, CD-34, HMB-45, synaptophysin, chromogranin, cytokeratin, and SMA. Ki-67 index was 2%.A diagnosis of cellular schwannoma of adrenal gland was confirmed.