Multicentric reticulohistiocytosis (MRH) is a rare systemic disorder that most often affects women in the fourth to fifth decades of life and is characterized by widespread cutaneous papules and nodules, often associated with a destructive arthritis. The characteristic histologic feature of the skin lesions, and of other affected organs, is the presence of histiocytes and multinucleated giant cells containing abundant eosinophilic cytoplasm with a “ground glass appearance.” Approximately 30% of the patients have an underlying malignancy suggesting MRH may be a paraneoplastic phenomenon. We describe a case of MRH associated with recurrent, metastatic breast carcinoma. (J Am Acad Dermatol 1998;39:864-6.)