Malignancy-associated multicentric reticulohistiocytosis

Multicentric reticulohistiocytosis (MR) is a rare systemic disorder of unknown etiology. Up to 25% of patients with MR have associated malignancies. We are reporting a case of a patient with MR who initially had an excellent clinical response to oral methotrexate and prednisone. Subsequent attempts of prednisone taper failed because of disease flare-up. Workup for associated malignancy revealed localized squamous cell carcinoma of the lung. The tumor was resected; methotrexate and prednisone were tapered and discontinued with complete remission of MR. A review of literature and the new advances and treatment modalities for MR is provided.