Myxoid adrenal cortical neoplasms.

Myxoid adrenal cortical neoplasms are rare, and to our knowledge, only about 23 cases have been reported in the literature, including 13 carcinomas and 10 adenomas. We recently experienced 4 cases of myxoid adrenal cortical neoplasms (3 benign and 1 borderline malignancy) and studied the clinical, histopathological, and immunohistochemical features of these neoplasms. There were 2 male and 2 female patients (age range, 37-61 years, mean, 48 years). All but 1 patient had hormone-related symptoms. The tumors weighed from 24.1 to 94 g (size, 4.1-9.8 cm). They were variably encapsulated with areas of hemorrhage. Histologically, the tumor cells were arranged in delicate arborizing cords or trabecula with myxoid areas varying from 30% to 70%. Three tumors were benign and 1 was of borderline morphology with mitoses of 3/10 high-power fields and mild to moderate nuclear pleomorphism. Two cases contained areas of myelolipomatous component. The tumor cells were positive for vimentin, synaptophysin, and inhibin but negative for cytokeratin. All patients are alive with no recurrence of their tumors or evidence of metastasis (follow-up of 14-20 months). Myxoid changes in adrenal cortical neoplasms are rare but can be seen in both an adenoma and a tumor of uncertain malignant potential. Because of prominent myxoid changes, other myxoid tumors occurring in the retroperitoneum should be excluded. The usual clinical and histological features can be applied to classify the lesions as benign, borderline tumor, or malignant. In our series, there was no case with frank malignant tumor.