Epithelioid and clear-cell variant of Kaposi sarcoma: A rare histopathologic subtype.

Kaposi sarcoma is a malignant vascular tumor consisting of multiple clinical subtypes and varying histopathologic patterns. We report a case of a 53-year-old African-American male with HIV/AIDS who presented multiple times with skin nodules, pain, and edema in his lower extremities, secondary to recurrent Kaposi sarcoma. The patient was treated with two courses of liposomal doxorubicin with improvement, but his symptoms recurred a third time. A biopsy specimen of one of the nodules showed prominent neoplastic cells of epithelioid morphology, some with clear-cell change, appearing to form rudimentary vessels in the superficial dermis. Further inspection of the deeper dermis revealed more classic findings of Kaposi sarcoma, including admixed spindle cells, poorly defined vessels, scattered apoptotic bodies, entrapped collagen bundles, and extravasated erythrocytes. Both the epithelioid and classic portions of the neoplasm stained positive for CD31 and human herpesvirus 8, supporting a diagnosis of Kaposi sarcoma. Prior to this case, the epithelioid variant of Kaposi sarcoma has been reported only twice in the literature. Recognizing this rare histopathologic variant of Kaposi sarcoma among its other histopathologic patterns may assist in accurate and expedient diagnosis of this well-recognized disease.