[Adrenocortical tumours]

Adrenocortical tumours have to be differentiated from cortical hyperplasias, medullary tumours and extra-adrenal tumours or metastases. These diagnoses are mostly possible using routine paraffin sections. In some cases, immunostaining for differing cortical and medullary tumours and metastases are necessary. Adrenal hyperplasias can be congenital or acquired. They are diffuse, micronodular or macronodular and may be inactive or induce a cortical hyperfunction. Very rarely, macronodular hyperplasias may transform into autonomous adenomas. Primary, pigmented adrenocortical disease is a rare, special type of primary adrenal Cushing's syndrome, showing many small tumours with pleomorphic cells and an atrophic surrounding cortical tissue. Adrenal adenomas are mostly unilateral and solitary tumours weighing less than 50 g. Adrenal cortical carcinomas are mostly larger. Like the adenomas, they may be inactive and may induce a hypercortisolism, a hyperandrogenism or (very rarely in carcinomas) a hyperaldosteronism. Differentiating cortical adenomas and carcinomas is difficult in some cases but is possible using a diagnostic algorithm. Myelolipomas are benign, inactive tumours composed of mature fat cells and bone marrow cells. They have to be differentiated from adenomas with myelolipomatous metaplasia. Further, rare primary cortical tumours are mentioned.