A Rare Presentation of a Large Embryonal Rhabdomyosarcoma at Retroperitoneal Region with Intra-thoracic Extension & Misdiagnosed as Lower Respiratory Tract Infection: A Case Report

Introduction: We are reporting a case of 18 year old boy who presented with features of lower respiratory tract infections and labelled as suffering from left suprarenal gland tumor. However, after complete evaluation, it is diagnosed as left retroperitoneal tumor extending into left thoracic cavity with involvement of left lower lobe lung. He underwent debulking surgery. Rhabdomyosarcoma (RMS ) originates from immature striated muscle and it is considered as the most aggressive malignant mesenchymal tumor. The most common location of RMS is head and neck region. The retroperitoneal presentation of embryonal RMS is extremely rare. The four histological features of RMS, classified by WHO are embryonal, alveolar, pleomorphic and spindle cell or sclerosing. Pleomorphic RMS has worse prognosis. The incidence of embryonal tumors is higher in males with bimodal age distribution, between 2-6 years and second peak between 10-18 years. Their detection is incidental when the size is small and as the size enlarges, symptoms helps in detection. Due to its rarity at retroperitoneal location, there is a lack of literature over the adjuvant treatment. As the size enlarges at retroperitoneal region, enblock resection with clear margins becomes a difficult task and if planned for R0 resection, multiorgan resection escalates surgical morbidity rate. Conclusion: It is a rare location of embryonal rhabdomyosarcoma at retroperitoneal region with rare presentation of intra-thoracic infiltration. R0 resection is the principle goal of surgical excision of retroperitoneal sarcoma.