# Disseminated Kaposi sarcoma presenting as an endophytic renal mass with concurrent primary effusion lymphoma: A case report

## TL;DR

A rare case of Kaposi sarcoma appearing as a kidney tumor and occurring with lymphoma in an untreated HIV patient is reported, highlighting the importance of early HIV treatment.

## Contribution

This case report presents a rare renal mass presentation of Kaposi sarcoma concurrent with primary effusion lymphoma in an untreated HIV patient.

## Key findings

- Kaposi sarcoma presented as an endophytic renal mass with lymphovascular invasion.
- The patient also had HHV-8-positive primary effusion lymphoma in the pleural fluid.
- Delayed antiretroviral therapy likely contributed to the aggressive disease progression.

## Abstract

Primary effusion lymphoma (PEL) is a rare, aggressive B-cell lymphoma associated with human herpesvirus-8 (HHV-8) and immunodeficiency, notably in untreated human immunodeficiency virus (HIV). Kaposi sarcoma (KS) is also an HHV-8-driven malignancy. Most cases of KS present with cutaneous manifestations, with less frequent visceral involvement. We present the case of a 63-year-old male with untreated HIV/AIDS who developed KS presenting as an endophytic renal mass with lymphovascular invasion and concurrent HHV-8-positive PEL. Biopsies confirmed KS in the kidney and PEL in the pleural fluid. Given profound immunosuppression, he was started on combination antiretroviral therapy and chemotherapy. This case represents a rare presentation of KS and highlights the aggressive course of HHV-8-driven malignancies in the setting of advanced HIV. Delayed antiretroviral initiation likely contributed to disease progression, emphasizing the critical role of early HIV treatment.

•HHV-8 (aka Kaposi sarcoma associated herpesvirus, KSHV) is a cause of Kaposi sarcoma (KS).•Kaposi sarcoma often presents as characteristic cutaneous vascular lesions.•KS can more rarely localize in viscera.•Our case is one of the only published cases of KS presenting as a renal mass.

HHV-8 (aka Kaposi sarcoma associated herpesvirus, KSHV) is a cause of Kaposi sarcoma (KS).

Kaposi sarcoma often presents as characteristic cutaneous vascular lesions.

KS can more rarely localize in viscera.

Our case is one of the only published cases of KS presenting as a renal mass.