Primary Non-Hodgkin's lymphoma originating from the masseter muscle

Abstract

Recently, as we experienced a case of extranodal NHL originating from the masseter muscle completely cured by chemotherapy with radiotherapy, we present the clinical, US, CT, and MR imaging findings in additional one case of biopsy-proved extranodal NHL (NK/T cell lymphoma) involving predominantly the masseter muscle also review thoroughly our collected cases of primary non-Hodgkin's lymphoma involving the muscles of mastication and facial expression. On the basis of our comprehensive review, we suggest two conclusions. First, primary muscle lymphoma particularly originating from muscles of mastication and facial expression is extremely rare, but primary muscle lymphoma should be considered in the differential diagnosis of muscular masses. Second, primary muscle lymphoma particularly originating from muscles of mastication and facial expression has similar clinical and radiological characteristics to primary skeletal muscle lymphoma involving other sites. However, the prognosis is more favorable in primary muscle lymphoma originating from muscles of mastication and facial expression compared to primary skeletal muscle lymphoma involving other sites.