Primary retroperitoneal mature cystic teratoma (dermoid cyst) in a 51-year-old male:Case report and historical literature review

OBJECTIVES Primary retroperitoneal mature cystic teratomas are exceedingly uncommon in males aged 50 years and above, and only seven cases have been reported in the literature so far. They usually occur in infants less than 6 months and young females. The aim of this article is to present a rare case of a 51-year-old male with a primary retroperitoneal mature cystic teratoma located in the right infrarenal area adherent to the psoas muscle and to discuss a historical literature review. METHODS An incidental hypoechoic, solid appearing 8.2 × 7.6 × 7.8 cm3 mass arising off the inferior pole of the right kidney was found on abdominal ultrasound during evaluation for a history of alcoholism. Computerized tomography (CT) scan revealed small calcifications in the lower part of the cystic mass. Laparotomy with excision of the retroperitoneal mass was performed. RESULTS On gross examination, the specimen consisted of a cyst filled with pale yellow greasy material with entrapped hair. Histopathologic examination revealed a dermoid cyst with focal chronic inflammation, dystrophic calcification, and foreign-body giant cell reaction. CONCLUSIONS Retroperitoneal mature cystic teratoma in an older male is extremely rare. Primary gonadal teratoma with retroperitoneal metastasis should be excluded first. Evaluation of age and location of tumor are critical for its prognosis. Complete excision of tumor is necessary to evaluate whether there are immature and solid elements which need long-term follow up due to the increased risk of malignancy.