Rhabdomyosarcoma - an Epidemiological and Histopathologic Study of 277 Cases from a Major Tertiary Care Center in Karachi, Pakistan

Aim: To present the epidemiologic data (age, gender, size etc) and histopathologic and immunohistochemicalfeatures of cases of rhabdomyosarcoma (RMS) reported in our department. Settings: Section of Histopathology,Department of Pathology and Microbiology, Aga Khan University Hospital, Karachi, Pakistan. Duration: Allcases of RMS diagnosed between January 1, 2003 and December 31, 2012 were included in the study.
Results:A total of 277 cases were included. Embryonal rhabdomyosarcoma (ERMS) was by far the dominant histologictype (87.4%) followed by alveolar type (ARMS)(9.4%). ERMS was much more common in males (64.0%)andover 65% of cases occurred in the first decade of life (over 90% in the first two decades). Head and neck regionwas commonest site for ERMS (46.7%), followed by the genitourinary system (16.1%). Over 65% cases of ARMSoccurred in the extremities. Over 80% cases of ARMS occurred in the first 3 decades of life. Immunohistochemicalstaining for Desmin and MyoD1 was positive in 96.7% and 85.4% respectively.
Conclusions: The epidemiologicdata and microscopic findings in our patients are similar to international published data on rhabdomyosarcoma.