A 65-year-old female, with a 4 month history of left upper quadrant discomfort, was identified as having a multi-loculated para-renal cyst on ultrasound scanning. CT identified a 13×11×10 cm heterogeneous mass arising from the left adrenal. An enlarged ill-defined left retro-crural lymph node was also noted. There was no history of weight loss. Past medical history was unremarkable. She was no medication. Examination was unremarkable apart from a BP of 181/102 mmHg.
Pre-operative endocrine assessment: normal electrolytes, 24 h UFC, urinary metanephrines (×2), testosterone, androstenedione, and DHEAs. Post 48 h low dose dexamethasone suppression test (LDDST) serum cortisol=55 nmol/l.
Based on size criteria, lymph node involvement and apparent low grade Cushings syndrome, the patient was informed that the mass most likely represented an adrenal adenocarcinoma and she was listed for surgery.
Under corticosteroid cover, left radical adrenalectomy, nephrectomy, and excision of the retro-crural lesion was undertaken. She was discharged on replacement hydrocortisone. After a normal short synacthen test hydrocortisone was withdrawn. A repeat LDDST was normal.
The solid cystic encapsulated mass weighed 670 g, measured 130×120×110 mm and was histologically separate from the left adrenal. Composed of spindle cells (positive for S-100 protein and Vimentin but negative for Actin) with Verocay bodies (Antoni A areas) and less cellular Antoni B areas, there was no evidence of cellular pleomorphism or mitotic figures. The retro-crural mass was composed of similar spindle cells.
Pathological diagnosis was a benign giant juxta-adrenal schwannoma and retro-crural schwannoma.
Retroperitoneal and juxta-adrenal schwannomas are extremely rare and may appear pre-operatively as adrenal tumours. Given their size (>4 cm) they may be confused with adrenocortical carcinomas and phaeochromocytomas, particularly given that some case reports highlight uptake of MIBG by these lesions. The failure of cortisol suppression following dexamethasone administration was, in retrospect, spurious.