Rhabdomyosarcoma of the gallbladder in a child: A case report

Introduction: Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children. The most common sites are the head and neck, followed by the genitourinary tract and the extremities. Gallbladder RMS in pediatric patient has rarely been reported in literature. Case presentation: A 5-year-old boy presented to our clinic with right upper quadrant abdominal pain for about 2 weeks. Abdominal ultrasound (US) and contrast-enhanced computed tomography (CT) revealed a 2.7 x 1.8 cm mass located in the neck of gallbladder. Magnetic resonance cholangiopancreatography (MRCP) confirmed the heterogeneous mass within the gallbladder without invasion of the surrounding structures, without gallbladder wall thickening, and without dilation of the biliary tree. Liver function tests, alpha-fetoprotein (AFP), carcinoembryonic agent (CEA), and cancer antigen 19-9 (CA19-9) were within normal values. The patient underwent an uneventful laparoscopic cholecystectomy. The pathology analysis confirmed a botryoid rhabdomyosarcoma (RMS) of the gallbladder with clear margins. No metastases were detected by postoperative positron emission tomography (PET) scan. The patient received 11 postoperative cycles of chemotherapy with vincristine, cyclophosphamide, and actinomycin-D. At one year of follow up he is well and free of disease. Conclusion: Due to its rare occurrence, the preoperative diagnosis of gallbladder RMS is challenging. Gallbladder RMS should be considered in the differential diagnosis of pediatric patients who present a gallbladder mass.