Disseminated Kaposi sarcoma with epithelioid morphology in an HIV/AIDS patient: A previously unreported variant

Anaplastic Kaposi Sarcoma of the Right Colon, in a Young Man With Acquired Immunodeficiency Syndrome: A Rare Variant in an Unreported Organ

Kaposi sarcoma (KS) arises in the context of 4 epidemiologic-clinical settings: Classic, endemic, epidemic, and iatrogenic; the most serious types are endemic and epidemic, and visceral involvement occurs mostly in the latter. Several morphological variants of KS have been described, of which the anaplastic one is highly aggressive. We report the case of an anaplastic KS arising from the ascending colon in a 32-year-old human immunodeficiency virus (HIV)-positive male patient with a 6-year history of multiple mucocutaneous KS. Anaplastic KS is most frequent in endemic and classic settings; there are ten cases of anaplastic KS reported in HIV-positive male patients. There is now strong evidence that KS is a clonal neoplasm characterized by chromosomal instability at the molecular level. According to the morphological spectrum and contemporary hypotheses of oncogenesis, conventional KS should be considered an incipient endothelial neoplasia, multiple or single, and anaplastic KS, the fully developed stage of the malignant neoplasm.

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.

Epithelioid Kaposi Sarcoma: A New Histological Variant

ABSTRACT

Cutaneous Kaposi sarcoma (KS) covers a broad spectrum both clinically and pathologically. Some histological patterns of KS may be difficult to recognize and must be differentiated from other vascular neoplasms. We report on a 56-year-old Peruvian man who had been diagnosed with classical KS on the right foot 2 years before the present episode. He presented in our clinic with new lesions on the left foot. Histopathological findings included areas showing epithelioid cells with moderate pleomorphism, growing in solid sheets. Immunohistochemistry showed strong nuclear staining with a granular nuclear staining pattern for human herpesvirus 8 in the epithelioid cells. A diagnosis of epithelioid Kaposi sarcoma was made, which should be considered a new histological variant.