Answer: Adenomatoid tumor

Histology: This is an unusual cellular process involving the adrenal gland. The lesion is composed of eosinophilic cells with prominent nucleoli and cytoplasmic vacuoles, which are epithelioid in some areas, spindled in others, and form cystic spaces simulating lymphatics in other areas. A prominent lymphoid infiltrate is also present. By immunohistochemistry, the lesional cells are diffusely immunoreactive for cytokeratin and for calretinin, but not for vascular markers (CD31 and CD34), or for Melan-A or inhibin.

Discussion: Adenomatoid tumors of the adrenal gland have been well characterized in the literature. Tumors typically contain multiple histologic patterns, including adenoid, angiomatoid, cystic, and solid. The main differential diagnosis is lymphangioma, which is suggested by the prominent lymphoid infiltrate associated by these lesions and their cystic architecture. Immunohistochemistry is important in making this distinction. Cytologically, the cells may have vacuoles which creates a differential diagnosis of metastatic signet ring cell carcinoma.

Reference(s):
– Am J Surg Pathol 2003;27:969-977.