Pseudoglandular myxoid adrenocortical adenoma with positive epithelial markers: a case report and review of the literature.

Myxoid adrenal cortical adenoma with a pseudoglandular structure is a special histological variant and is extremely rare. We report about a 32-year-old Chinese woman with a right adrenal mass during a routine physical examination. The cut surface of the mass had a vague nodular, which gross appearance was pale, yellowish, and semitransparent. Histologically, the region is mostly characterised by pseudoglandular pattern with myxoid stroma. They are filled with clear cells or eosinophilic cells, as well as semitransparent regions, in which anastomosing small eosinophilic cells arranged in pseudoglandular, cord-like, or wreath-shaped structure float in the mucous pool. Immunohistochemical staining shows Melan-A, vimentin, and CD56 were positive and CK (AE1/AE3) were nucleus-side staining. A small number of tumor cells were positive for alpha-inhibin and synaptophysin, ki-67 labeling index was 3%. EMA, chromogranin A, WT-1, and P63 were negative. This report aimed to emphasize pseudoglandular patterns with mucus secretion which could occur in adenomas of the adrenal cortex, nucleus-side positive for CK is remarkable. However, this type may have malignant potential, so regular follow-up is needed.