Atypical Nodal Kaposi Sarcoma in HIV Infection. A case report and literature review

Kaposi sarcoma is an angioproliferative neoplasm driven by human herpesvirus 8 (HHV-8), most commonly observed in immunocompromised individuals, particularly those with untreated human immunodeficiency virus infection. It classically presents with cutaneous and mucocutaneous lesions; however, atypical forms without skin involvement, especially those with predominant lymph node disease, are rare and frequently lead to diagnostic uncertainty. We report the case of a 26-year-old male with recently diagnosed HIV infection and no prior antiretroviral therapy, who presented with a two-week history of persistent fever, constitutional symptoms, abdominal pain, and progressive intolerance to oral intake. On admission, he exhibited hemodynamic instability, severe anemia, thrombocytopenia, and progressive renal dysfunction. Imaging studies revealed generalized lymphadenopathy involving multiple nodal chains, bilateral pleural effusion, hepatosplenomegaly, and free abdominal fluid, suggesting a systemic process. Initial diagnostic considerations included lymphoma, disseminated infection, and other HIV-associated malignancies. An excisional inguinal lymph node biopsy demonstrated a vascular mesenchymal neoplasm composed of spindle cells, and immunohistochemical analysis confirmed Kaposi sarcoma with nuclear positivity for HHV-8. Notably, no cutaneous or mucosal lesions were identified throughout the clinical course. Nodal Kaposi sarcoma without cutaneous involvement represents an uncommon and underrecognized presentation, particularly in young patients with untreated HIV infection. Its clinical features frequently overlap with lymphoproliferative disorders and opportunistic infections, contributing to diagnostic delays. The pathogenesis is driven by the interplay between HIV-induced immunosuppression, chronic immune activation, and HHV-8–mediated oncogenesis. In this context, early histopathological evaluation remains essential for definitive diagnosis, as imaging findings lack specificity. This case highlights the importance of including Kaposi sarcoma in the differential diagnosis of unexplained lymphadenopathy in patients with HIV, even in the absence of cutaneous lesions. Recognition of atypical presentations is critical to ensure timely diagnosis and appropriate management, ultimately improving patient outcomes.