title: Diagnostic utility of double immunostaining of a urine cytology preparation for cytokeratin 20/p53 expression in a young woman with micropapillary urothelial carcinoma of the renal pelvis presenting as an unknown primary malignancy.
abstract: Atypical urine cytology (CYT) triggers a cystoscopic or another ancillary investigation that targets urothelial neoplasms. We report a case presenting as an unknown primary malignancy, which illustrated the diagnostic utility of direct double immunostaining for cytokeratin 20 (CK20)/p53 expression in a urine CYT specimen. A 42-year-old woman visited the emergency room for pain in her right lower abdominal quadrant. Computed tomography revealed postrenal obstructive hydronephrosis, and her urine CYT showed malignancy, type undetermined. Atypical cells that are positive for cytoplasmic expression of CK20 and nuclear expression of p53 could facilitate the decision to perform a nephroureterectomy for urothelial carcinoma.
authors.affiliation: Address: Department of Pathology, Inje University, Sanggye Paik Hospital, Seoul, Korea.
authors.forename: Hyun-Jung
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Urology, Inje University, Sanggye Paik Hospital, Seoul, Korea.
authors.forename: Lucky
authors.initials: L
authors.lastname: Sung
authors.affiliation: Address: Department of Pathology, Inje University, Sanggye Paik Hospital, Seoul, Korea.
authors.forename: Jung-Yeon
authors.initials: JY
authors.lastname: Kim
authors.affiliation: Address: Department of Pathology, Inje University, Sanggye Paik Hospital, Seoul, Korea.
authors.forename: Kyeongmee
authors.initials: K
authors.lastname: Park
keywords: Cytokeratin 20; double immunostaining; p53; unknown primary; urothelial carcinoma