Retroperitoneal Teratoma in a Transplanted Patient: Case Report and Review

The development of de novo neoplasms in solid organ transplantation is multifactorial. In addition to common factors in the general population, there are specific factors of the disease related or not to chronic renal failure and factors inherent to the transplant itself such as immunosuppression.

The aim of this study is to describe the case of a kidney recipient with a retroperitoneal teratoma, his satisfactory treatment, and a brief literature review.

The case of 59-year-old male patient who received a living donor transplant in 2011, with conventional immunosuppression, graft protocol biopsy per year reported as normal, and follow-up without eventualities is described. The patient's symptoms began in December 2020 with abdominal pain resistant to analgesics, asthenia, and adynamic. Contrast tomography showed a retroperitoneal tumor 25.8 × 16.9 × 19 cm; tumor markers: alpha fetoprotein, 2.16 ng/mL; cancer antigen 19-9, 524.5 UI/ml; and carcinoembryonic antigen, 67.53 ng/mL. Resection of a 25 × 25 × 20 cm retroperitoneal tumor between the vena cava and aorta with 2 L of mucus content was performed. The patient was discharged from the hospital on the second day, with uresis 1 mL/kg/h, and at one month with adequate renal function, and 0.94 mg/dL of serum creatinine. A definitive histologic report was compatible with retroperitoneal mature teratoma.

Primary retroperitoneal mature teratoma is rarely evidenced in adult patients, usually asymptomatic, and the definitive diagnosis always is established after histologic evaluation. Surgical resection is the main treatment with the complete removal of the tumor and long-term monitoring is needed because of the risk of malignancy.