Upper extremity myxofibrosarcoma mimicking an erosive inflammatory arthritis: a case report.
Myxofibrosarcoma is a malignant fibroblastic soft tissue neoplasm containing a variable amount of myxoid stroma that commonly presents as a slow-growing mass in elderly patients. The neoplasm may be superficial or deep to the muscle fascia and characteristically has an infiltrative growth pattern with a dominant or multinodular mass. We describe an unusual case of high-grade myxofibrosarcoma of the wrist and forearm that infiltrated the muscles, tendons, and wrist joint, causing bone erosions. The tumor was mistakenly diagnosed as synovitis and a chronic, erosive, inflammatory process. The diffuse nature, absence of a dominant mass, and radiographic appearance complicated the diagnosis. Although neoplasms of the synovial spaces are rare, this case demonstrates that tumors with a highly infiltrative growth pattern can mimic inflammatory synovitis and that neoplasms should be considered in the differential diagnosis when clinical and laboratory features are discordant with the imaging appearance.
['Colak|Ceylan|C|http://orcid.org/0000-0002-8278-9302', 'Kilpatrick|Scott E|SE|', 'Mesko|Nathan W|NW|', 'Winalski|Carl S|CS|']
D000368:Aged D000671:Amputation D001168:Arthritis D003937:Diagnosis, Differential D005260:Female D005354:Fibrosarcoma D006801:Humans D008279:Magnetic Resonance Imaging D019042:Muscle Neoplasms D009236:Myxosarcoma D011859:Radiography D034941:Upper Extremity
Myxofibrosarcoma Infiltrative growth pattern Synovitis