Primary Retroperitoneal Mucinous Cystadenocarcinoma in a Male Patient: A Case Report.

Primary retroperitoneal mucinous cystadenocarcinoma (PRMC) is an uncommon malignant neoplasm with few reported cases, particularly among male patients. Currently, only nine documented cases have been reported worldwide, including the present case. The present case report describes the incidental detection of PRMC in an 86-year-old male patient. Despite being offered surgical intervention, the patient initially opted against treatment. Consequently, follow-up imaging examinations were performed for 3 subsequent years. The tumor, initially measuring 31 × 32 × 31 mm, gradually increased to 58 × 60 × 59 mm. Subsequently, the patient underwent laparoscopic retroperitoneal tumor resection. Histopathological examination revealed adenocarcinoma characterized by intestinal differentiation. The patient has exhibited no evidence of disease for 1 year postoperatively. The present case is noteworthy, as this disease rarely occurs in men, thereby offering significant potential for educational and scientific contributions. Notably, the patient's age, longitudinal observation of tumor progression through imaging over a period of 3 years, and complete surgical excision of the tumor are salient features of this case. These findings may prove useful in the diagnosis and treatment strategy for male patients with PRMC.