Black adrenal adenoma causing subclinical Cushing’s syndrome complicated with pheochromocytoma

INTRODUCTION: The development of adrenocortical adenoma and pheochromocytoma within the same adrenal gland is very rare. Furthermore, no reports have described coincident black adrenal adenoma and pheochromocytoma. We herein report a rare case of coincident black adrenal adenoma and pheochromocytoma in the same adrenal gland. CASE PRESENTATION: A 71‐year‐old Japanese woman was hospitalized because a right adrenal tumor had been incidentally found by computed tomography. She was diagnosed with subclinical Cushing’s syndrome and underwent laparoscopic right adrenalectomy. The tumor contained two adrenal nodules. The cut surface of the larger nodule was brownish‐black on macroscopic examination. Pathological studies revealed coincident black adrenal adenoma and pheochromocytoma. CONCLUSION: To the best of our knowledge, this is the first report of coincident black adrenal adenoma causing subclinical Cushing’s syndrome and pheochromocytoma in the same adrenal gland. The mechanism of this rare scenario is unclear, and further study is necessary.