Occult prostatic adenocarcinoma presenting as a ureteric tumor and expressing KIT and PDGFRA

Abstract

Prostatic carcinoma (PC) may present multiple metastases of unknown primary (most commonly bone metastases), the occult PC. PC expressing KIT and PDGRA has not been reported. There have been no reports of occult PC manifesting as a ureter tumor. An 83-year-old man presented with flank pain. Imaging showed a ureter tumor. Ureteronephrectomy was performed. The author diagnosed the ureteric tumor as high-grade urothelial carcinoma, Postoperative imaging showed multiple tumors in liver and lymph nodes. The clinical diagnosis was hepatocellular carcinoma and cirrhosis, and the patient received radiofrequency ablation (RFA). The patient further presented hematuria, and cystscopy revealed an elevated tumor of urinary bladder, and TUR-BT was performed. Histologically, TUR-BT specimens show monotonous medullar proliferation of high-grade malignancy arranged in solid nests and acinar formations. Immunohistochemically, tumor cells were positive for PSA, α-methyl CoA racemase (AMACR), cytokeratin (CK) AE1/3, CK CAM5.2, CK8, CK18, CK19, CEA, synaptophysin, KIT, PDGFRA, p53 and Ki-67 (labeling index = 90%). No mutations of KIT and PDGFRA were noted. Since PSA and AMACR were positive, the definite diagnosis of PC (Gleason 9) metastatic to multiple sites including ureter and bladder was made.