ABSTRACT
Primary retroperitoneal teratomas are rare non-seminomatous germ cell tumors that arise from embryonal tissues. They form only 5%-10% of all retroperitoneal tumors. These are usually asymptomatic or present as lump or mass with compressive symptoms. Most of the patients are diagnosed by characteristic computed tomography findings. The chances of malignant transformation are rare. Complete surgical resection is the definitive treatment for most patients. We had a 19 years old young man, presented with pain abdomen and awareness of a lump in the right upper abdomen. Contrast-enhanced computed tomography (CECT) of the abdomen revealed a heterogeneous soft tissue mass in the retroperitoneum with calcification. He was successfully treated with en-bloc complete surgical resection. Histopathology confirmed benign mature teratoma including all three germ layers. The patient is doing fine at nine months of follow-up and planned for CECT abdomen. Primary mature teratomas arise in the retroperitoneum due to failure of germ cells migration to their normal location. Germ cells undergo differentiation into various germ layers. Teratomas can be classified as mature, immature, or non-dermal based on their histopathological characteristics. Although complete surgical excision is the mainstay of treatment, malignant teratomas frequently recur. So, annual follow-up is recommended with imaging. A classic mature teratoma requires careful examination and interpretation of the imaging. The amount of immature components determines outcome and recurrence in these patients so en-bloc surgical resection is the treatment of choice.
