Introduction Signet‐ring cell carcinoma is an extremely rare histological variant of upper urinary tract carcinoma, associated with poor prognosis. Case presentation We report a case of a 75‐year‐old female diagnosed with left primary upper urinary tract signet‐ring cell carcinoma, initially treated with surgery. Post‐surgical development of multifocal metastases was followed by a devastating clinical course. An autopsy confirmed the tumor's primary origin in the upper urinary tract. Conclusion We experienced a case of upper urinary tract signet‐ring cell carcinoma, with a rare opportunity to thoroughly confirm its primary site with an autopsy.

IntroductionProstatic metastasis from testicular cancer is extremely rare, with only 10 reported cases, all of which were diagnosed as relapse. Herein, we report the case of a patient with concurrent testicular cancer and prostatic metastasis.Case presentationA 57‐year‐old man presented at our emergency department with urinary retention. A painless mass was found in the right scrotum, and computed tomography showed lung, mediastinal, and liver metastases, and an enlarged prostate. Tumor markers were measured in 2057 U/L lactate dehydrogenase, 2460 mIU/mL human chorionic gonadotrophin, 1303 ng/mL alpha‐fetoprotein, and 1.51 ng/mL prostate specific antigen. An orchiectomy and biopsy were performed; the pathological results showed immature teratomas, embryonal carcinomas, choriocarcinomas, and seminomas in the testis, and embryonal carcinomas in the prostate, liver, and mediastinum. The patient refused chemotherapy and died 3 months following diagnosis.ConclusionProstatic metastasis should be considered in cases of dysuria or prostate enlargement in testicular cancers.