Biochemically silent phaeochromocytoma presenting with non-specific loin pain

Abstract

A 55-year-old woman presented with a 4-month history of right-sided non-specific loin pain and 6 kg weight loss. A CT scan of the abdomen and pelvis showed an incidental 4.5 cm right-sided adrenal lesion which was not typical of an adrenal adenoma. This was further confirmed on MRI of the adrenals. Biochemical investigations to investigate for a functional adrenal lesion included serum catecholamines and metanephrines, an aldosterone to renin ratio and an overnight dexamethasone suppression test. These were all negative. A laparoscopic adrenalectomy was performed in view of the large size of the lesion. Histology was consistent with a phaeochromocytoma, which confirmed the diagnosis of a non-secreting phaeochromocytoma. Non-secreting phaeochromocytomas are rare and usually found in patients with known genetic mutations. Adrenal lesions not related to any mutations similar to our case are even rarer and reported even less in the literature.