Background: Kaposi's sarcoma (KS) is a vascular malignant tumor characterized by human herpesvirus 8 infection of neoplastic cells. Diffuse cutaneous lesions represent the classical clinical presentation. This case report describes the first fine needle aspiration cytology findings of a primary lymph nodal KS, a rather unusual localization of the disease.
Case: A 28-year-old, apparently healthy man saw a surgeon for right inguinal node enlargement without other symptoms. The clinician performed fine needle aspiration and made a preliminary diagnosis of a neoplasm of probable mesenchymal origin, not otherwise specified. The lymph node was excised, and the final histologic diagnosis was primary lymphoadenopathic KS. A serologic test revealed antibody positivity for HIV.
Conclusion: The diagnosis of primary KS of the lymph node, in the absence of any other clinical manifestation, was the first sign of HIV infection.