ABSTRACT
Embryonal rhabdomyosarcoma (RMS) is a rare type of sarcoma, primarily seen in the pediatric and adolescent population. Three subtypes of embryonal RMS are described, with the botryoid type being the most common. The incidence of this disease in adult females is 0.4% to 1% with the affected age group being patients in the third to fourth decade of life. It is exceedingly rare in patients above 40 years of age. We describe the case of a 48-year-old female, gravida 9 para 5, who presented with abnormal vaginal bleeding and an exophytic mass on examination. Given her lack of requirement of maintaining parity, she underwent radical surgery. The tumor was 8 cm in the largest dimension with a high histologic grade and some cartilaginous differentiation. Immunohistochemical stains were positive for vimentin, CD99, myogenin, and MyoD1 consistent with a diagnosis of embryonal rhabdomyosarcoma, botryoid subtype. Based on high survival rates when treated with aggressive adjuvant chemotherapy, a decision was made to treat the patient with the ARST0331 regimen. We discuss the diagnostic pathologic features of the disease, the epidemiology, and the most common presentation along with prognostic factors, treatment strategies, and outcomes.