Adrenal adenoma associated with raised metanephrine level: A case report

Adrenal adenomas are benign neoplasms of the adrenal cortex which can be functional or non-functional. The functional tumors manifest as Cushing syndrome. Rarely, they are associated with high levels of metanephrine due to pheochromocytoma. Here, we report an extremely rare case of adrenal adenoma associated with raised metanephrine, but no histopathological evidence of medullary changes.

A 30-year female with diabetes, hypothyroidism, and hypertension was admitted for resistant hypertension, severe refractory hypokalemia, decreased sleep, fearfulness, anxiety, and palpitation. Facial puffiness, ecchymoses on upper and lower limbs, and bilateral pedal edema were present. Laboratory investigation revealed raised 24-hour-urine cortisol (52.5 μmol/dL) and metanephrine (56.00 μmol/24 h), very low ACTH (<5.0 pg/mL), and negative dexamethasone suppression test. MRI brain findings were normal. CT scan of the abdomen revealed a well-defined soft tissue lesion in the right adrenal gland and diffuse osteopenia vertebrae. Hence, diagnosis of Cushing Syndrome secondary to adrenal adenoma, and pheochromocytoma was made, and laparoscopic adrenalectomy was done under pheochromocytoma protocol. The patient improved dramatically, thereafter. Histopathological findings showed adrenocortical adenoma only; no evidence of pheochromocytoma was found.

We came across many articles reporting adrenal adenoma associated with high levels of metanephrine due to co-existing pheochromocytomas either in the ipsilateral or contralateral adrenal gland. But, in our case, the adrenal adenoma was associated with high metanephrine levels with no histopathologic features of pheochromocytoma.

Cushing syndrome due to Cortisol secreting Adrenal adenoma can be associated with biochemical and clinical features suggestive of Pheochromocytoma which could resolve after adrenalectomy.