Laparoscopic Resection of a Rare Retroperitoneal Dermoid Cyst in a 78-Year-Old Woman: A Case Report.

BACKGROUND Primary retroperitoneal tumors (PRTs) are uncommon, with retroperitoneal dermoid cysts being particularly rare. The cystic cavity of mature cystic teratomas (dermoid cysts) is lined with squamous epithelium and primarily filled with sebaceous material. These lesions often lack specific symptoms, leading to delayed diagnosis. Imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI) are crucial for identifying these lesions, but definitive diagnosis relies on pathological examination. Surgical resection is the primary treatment, particularly for symptomatic or enlarging lesions. This report describes a case of a 78-year-old woman presenting with hydronephrosis secondary to a solitary retroperitoneal mature cystic teratoma (dermoid cyst) removed by laparoscopic resection. CASE REPORT A 78-year-old woman presented with left renal occupancy and severe hydronephrosis detected during routine health screening. Imaging studies revealed a retroperitoneal cystic mass compressing the upper urinary tract. She underwent laparoscopic resection of the mass and nephrectomy. Histopathological examination confirmed the diagnosis of an isolated retroperitoneal mature cystic teratoma. Postoperatively, she recovered well and remained asymptomatic during follow-up. CONCLUSIONS Retroperitoneal dermoid cysts are rare and pose diagnostic challenges due to their nonspecific clinical and imaging features. Early diagnosis and surgical intervention are critical to preventing complications and preserving organ function. This case report discusses the importance of preoperative evaluation and early treatment, highlighting the urgency of optimizing and standardizing the diagnosis and management of such diseases.