Abstract

Intralymphatic histiocytosis (ILH) is a rare, benign cutaneous disorder associated with underlying systemic disease. It is most commonly seen in rheumatoid arthritis, although it has been reported in breast, skin, and colon malignancies, metallic orthopedic implants, inflammatory bowel disease, and in the absence of an identifiable underlying disease. The exact etiology of ILH and extent of associated disease states is still unknown. We present a case of ILH in association with human immunodeficiency virus (HIV). A 53-year-old man with past history of well controlled HIV, complicated by pulmonary Kaposi sarcoma 12 years ago with no evidence of residual disease, presented with recurrent febrile episodes and thigh myalgia followed by painful macules and patches on his bilateral lower extremities. These episodes occurred intermittently for approximately 10 years. Extensive systemic workups for infectious disease, malignancy and connective tissue disease were negative in the past. On physical exam patchy erythematous macules coalesced into patches on his bilateral shins. A punch biopsy of the rash on the right lower extremity revealed a sparse perivascular and interstitial infiltrate of lymphocytes and eosinophils with associated vessels engorged with eosinophils and histiocytes. On immunohistochemistry, the intralymphatic cells stained with CD68 and CD163, with non-continuous D2-40 staining of the vessel walls. The cells were negative for CD3, CD20, CD30, CD34, CD79a, S100, and CD1a. Stains for infectious etiologies were negative. The clinical and histologic findings were consistent with ILH. This case represents the first possible association between HIV and ILH and highlights the importance of considering this entity even in the absence of rheumatoid arthritis.

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