Introduction We report a prostate cancer case diagnosed during leuprorelin treatment for spinal and bulbar muscular atrophy which is a X‐linked recessive, lower motor neuron disease. Case presentation A 64‐year‐old man who had received leuprorelin treatment over 3 years for his spinal and bulbar muscular atrophy presented with an enlarged prostate accompanied by abdominal pain and constipation. An abnormally high serum prostate‐specific antigen of 17.7 ng/mL and a low (castration level) serum testosterone level of 0.23 ng/mL were measured. Prostate needle biopsy revealed adenocarcinoma of the prostate. Orchiectomy, darolutamide, and radiation therapy for the prostate were initiated, resulting in a favorable response which was maintained at 12 months of treatment. Conclusion Prostate cancer can occur even when leuprorelin is used for spinal and bulbar muscular atrophy; therefore, checking serum prostate‐specific antigen to screen for prostate cancer before leuprorelin administration should be considered.

Introduction We present a case of mucinous adenocarcinoma of the prostate with testicular and lung metastases following robot‐assisted radical prostatectomy, androgen deprivation therapy, and radiotherapy. Case presentation A 73‐year‐old man with a prostate‐specific antigen level of 4.3 ng/mL was diagnosed with prostate cancer. Following the robot‐assisted radical prostatectomy, the pathological diagnosis was mucinous adenocarcinoma of the prostate (pT3bpN0, Gleason score of 4 + 4). Salvage hormonal therapy and irradiation were performed after the prostatectomy. Enlargement of the left testis was noted, and 28 months after prostatectomy, computed tomography detected a left testicular tumor and nodular lesions in the bilateral lungs. The histopathological diagnosis of left high orchiectomy was metastasis of a mucinous adenocarcinoma of the prostate. Chemotherapy with docetaxel followed by cabazitaxel was initiated. Conclusion Mucinous prostate adenocarcinoma with distal metastases following prostatectomy has been managed for longer than 3 years with multiple treatments.

Introduction We present a case of urothelial carcinoma in a renal allograft successfully treated with pembrolizumab. Case presentation A 39‐year‐old woman presented with nausea and anorexia 9 years after a renal transplantation. Positron emission tomography revealed a neoplasm of the renal pelvis of the allograft and multiple lymph nodes with peritoneal metastasis. A diagnosis of a non‐muscle‐invasive bladder tumor with peritoneal dissemination and jejunal metastasis of urothelial carcinoma was made. After five cycles of gemcitabine and carboplatin, the tumor progressed and pembrolizumab was administered. One week after the first dose, the allograft was rejected, necessitating arterial embolization. After the second cycle, the patient developed Stevens‐Johnson syndrome. After discontinuing pembrolizumab, positron emission tomography revealed no increased tumor activity. A complete response was achieved for 21 months without additional treatment. Conclusion Pembrolizumab was effective in treating urothelial carcinoma of the renal allograft; however, allograft rejection and loss should be considered.