Abstract

Multicentric reticulohistiocytosis (MRH) is a rare form of non-Langerhans cell histiocytosis that often presents with skin- and joint-based symptoms. MRH is frequently associated with autoimmune diseases, such as rheumatoid arthritis, but may also present as a paraneoplastic disease in 15-30% of cases, associated predominately with carcinoma and melanoma. We found only one case of MRH associated with a hematologic malignancy (Burkitt lymphoma) reported in the literature; however, there was concurrent adenocarcinoma in that case. Our patient was a 63-year-old healthy male presenting with a four-month history of arthralgia and a rash. Physical examination revealed maculopapular, erythematous, slightly pustular eruption involving the eyebrows, ears, and the dorsa of both wrists, extending over the MCP joints. Biopsy revealed a dermal proliferation of PAS-positive, diastase-resistant, large multi-nucleated histiocytes with eosinophilic, ground-glass cytoplasm, consistent with multicentric reticulohistiocytosis. He was treated with corticosteroids, methotrexate, and adalimumab. Five years later, he was noted to have lymphocytosis with atypical lymphocytes present on peripheral blood smear. Flow cytometric analysis revealed a monoclonal B cell population with expression of CD19, CD20, CD23, CD5, and kappa light chain. Peripheral blood FISH revealed IgH-cyclin D1 translocation. The hematologic findings were diagnostic of mantle cell lymphoma. The patient had no evidence of concurrent malignancy at that time. He initially achieved remission, but has recently experienced a relapse and is currently receiving palliative chemotherapy. To the best of our knowledge, this is the first reported case of an isolated hematologic malignancy arising in a patient with a history of MRH, and adds to the spectrum of diseases associated with MRH.

Financial Disclosure:
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