Rhabdomyosarcoma infiltrating bone marrow.

We present a case of 26-year-old male, previously diagnosed as rhabdomyosarcoma (RMS) of perineal region. The peripheral smear showed a leukoerythroblastic picture with an occasional atypical cell. The bone marrow aspirate and biopsy showed monotonous sheets of malignant cells. On immunohistochemistry the tumor cells were strongly positive for desmin and negative for CD34 and CD117. This case illustrates the morphology and IHC findings in a case of RMS. Immunostains like CD34 and CD117 should be included to rule out a possibility of acute leukemia.