Lymphangioma-like Kaposi Sarcoma: A Rare Case Report with Literature Review

Summary: A 26-year-old man with a 3-year history of AIDS presented with extensive sarcomatous, fungating, weeping lesions involving the bilateral groin areas, accompanied by moderate-to-severe lymphedema. Two years prior, he was diagnosed with Kaposi sarcoma (KS) manifesting as violaceous patches, papules, and plaques on the soft palate, face, extremities, and trunk. Despite resolution of head and neck lesions following systemic chemotherapy and HIV treatment, groin lesions progressed with lymphedema. His current CD4 count is 14. Histologic examination of the excised groin lesions revealed reactive epidermal hyperplasia overlying a papillary dermis with dilated vascular spaces lined by bland-appearing endothelial cells. Typical features of classic Kaposi sarcoma, including dense spindle cell proliferation, nuclear atypia, blood-filled vascular channels, and lymphoplasmacytic infiltrate were also present. Immunohistochemical stains for CD34, D2-40, and HHV-8 were positive in neoplastic cells, confirming the diagnosis of lymphangioma-like Kaposi sarcoma (LLKS). LLKS is a rare histological variant of Kaposi sarcoma, reported in fewer than 40 cases in literature. It occurs across various KS clinical subtypes and mimics vascular tumors such as lymphangioendothelioma, hobnail hemangioma, retiform hemangioendothelioma, spindle cell hemangioma, and low-grade angiosarcoma. Preliminary evidence suggests LLKS may be less aggressive than other variants, though further research is needed to validate this.