Cytological features of myxoid adrenocortical adenoma with a pseudoglandular component: a case report with differential diagnostic considerations

Myxoid adrenocortical tumors are extremely rare neoplasms with only nine adenomas and eleven carcinomas reported in the literature. They occasionally have a pseudoglandular component resembling metastatic mucinous adenocarcinoma in the adrenal gland. However the cytological features of this unusual tumor have not been previously described. We report here the first cytopathological study of a myxoid adrenocortical adenoma with a pseudoglandular component, contributing especially to the differential diagnosis from metastatic mucinous adenocarcinoma. Two major cytopathological features distinguishing myxoid adrenocortical adenoma from metastatic mucinous adenocarcinoma in the adrenal gland are: (1) the myxoid material is found only in the extracellular space, and not in the cytoplasm; and (2) nuclei are usually located in the central portion of the cytoplasm, and not compressed to the periphery. Careful observation of these cytological features and positive immunoreactivity to Melan A, alpha-inhibin and synaptophysin can lead to the correct diagnosis.