We report 38 pleomorphic rhabdomyosarcomas in adults, explore morphologic variants, and discuss our experience with both specific and nonspecific skeletal muscle markers in these tumors. Clinical data, morphology, and immunohistochemistry were reviewed. Electron microscopy was performed. Of 38 cases, there were 28 males and 10 females. The appropriate diagnosis of PRMS is significant as it is a high-grade sarcoma, with an aggressive clinical course.
Pleomorphic rhabdomyosarcoma is considered rare and controversial, especially in children.
Although pleomorphic rhabdomyosarcoma has been observed in children, its sparcity has taken it out of current childhood rhabdomyosarcoma classifications. We report four pediatric cases of pleomorphic rhabdomyosarcoma, review morphologic, immunohistochemical, and ultrastructural features, and discuss the rare need to include this category in children. The Soft Tissue Registry of the Armed Forces Institute of Pathology was searched for cases coded as pleomorphic rhabdomyosarcoma from 1970 to the present. Only cases in patients less than 21 years old were included. Clinical data, morphology, and immunohistochemical stains were reviewed and follow-up was obtained.