Multicentric reticulohistiocytosis: case report.

A 64-year-old woman developed slowly expanding asymptomatic red bumps on the hands and in the face since 1 year. Histopathological examination showed mononucleated and multinucleated giant cells with a characteristic "ground glass" appearance. Based on the clinical and histopathological findings, we made the diagnosis of multicentric reticulohistiocytosis (MRH). This rare variant of histiocytosis was described for the first time in 1950. Clinically, the disorder is characterized by papulonodular cutaneous lesions, and a severe and often destructive arthropathy. The reticulohistiocytoses are a rare group of closely related non-Langerhans cell histiocytosis that most commonly manifest in adults. Because MRH can be associated with an underlying malignancies, and an interdisciplinary examination and regimen of these patients is advisable.