Incidental finding of probable epididymal adenomatoid tumor and tubulocystic renal cell carcinoma in a patient with epididymo-orchitis: a case report.

BACKGROUND: Tubulocystic renal cell carcinoma is a rare type of renal cell carcinoma (< 1%). Tubulocystic renal cell carcinoma was first acknowledged by the World Health Organization in 2016. Tubulocystic renal cell carcinoma has low aggressivity and has a metastasis rate of around 6%. Adenomatoid tumor of the epididymis is an asymptomatic rare, benign mesothelial neoplasm of the paratesticular region, most commonly occurring at the tail of the epididymis. This tumor is prevalent in the third to fifth decades of life with no malignant potential. There have been no reported cases of both diagnoses existing at the same time in a patient.

CASE PRESENTATION: We aim to present the first case in literature, according to our knowledge, of both tubulocystic renal cell carcinoma and probable adenomatoid tumor existing at the same time in a 67-year-old Lebanese male presenting with epididymo-orchitis, who on ultrasound was found to have an incidental finding of probable adenomatoid tumor located in the tail of the right epididymis, as suggested by the radiologist and the urology team. The patient was also found to have a renal mass that was described earlier to be a Bosniak type 2 renal cyst. The patient underwent left partial nephrectomy. A pathological examination revealed tubulocystic renal cell carcinoma.

CONCLUSIONS: Tubulocystic renal cell carcinoma might be the result of progression from Bosniak type 2 renal cysts. They are best treated by a nephron-sparing surgical approach. Physical examination and testicular ultrasound are important tools in the diagnosis of scrotal and epididymal tumors. The benignity of adenomatoid tumor of the epididymis is reassuring and is a reason why it may usually be underreported.