Primary Mucinous Adenocarcinoma of the Testis: A Case Report and Review of the Literature

Background: Primary ovarian surface epithelial carcinoma of testis and paratestis is very rare, especially mucinous subtype. We report a case of a 48-year-old man with primary mucinous adenocarcinoma of the testis and discuss its gross, histological and immunohistochemical features based on limited reports. Case presentation: A case of a 48-year-old male patient with mucinous adenocarcinoma of the testis is reported. The tumor was confined to the testis and separated from the epididymis. The tumor has neither interstitial infiltration nor metastasis to other organs, nor ovarian or germ cell tumor components. Immunohistochemical analysis showed that the tumor epithelial cells expressed CK20, CK7, CDX-2 proteins, whereas expression of SATB2 was absent. Ki-67 protein was weakly expressed in epithelial cells. The mucinous adenocarcinoma in the present case had the immunohistochemical characteristics of intestinal mucosa. Conclusions: : Primary mucinous adenocarcinoma of the testis is rare and there is no standard treatment. The main treatment is surgical resection, but there is no effective treatment for metastatic tumors. Paclitaxel, platinum-based chemotherapeutics may have some curative effects, but there is still a lack of robust clinical evidence.