Cancer of unknown primary finally revealed to be a metastatic prostate cancer: a case report.
The vast majority of patients with metastatic prostate cancer present with bone metastases and high prostate specific antigen (PSA) level. Rarely, prostate cancer can develop in patients with normal PSA level. Here, we report a patient who presented with a periureteral tumor of unknown primary site that was confirmed as prostate adenocarcinoma after three years with using specific immunohistochemical examination. A 64-year old man was admitted to our hospital with left flank pain associated with masses on the left pelvic cavity with left hydronephrosis. All tumor markers including CEA, CA19-9, and PSA were within the normal range. After an exploratory mass excision and left nephrectomy, the pelvic mass was diagnosed as poorly differentiated carcinoma without specific positive immunohistochemical markers. At that time, we treated him as having a cancer of unknown primary site. After approximately three years later, he revisited the hospital with a complaint of right shoulder pain. A right scapular mass was newly detected with a high serum PSA level (101.7 ng/ml). Tissues from the scapular mass and prostate revealed prostate cancer with positive immunoreactivity for P504S, a new prostate cancer-specific gene. The histological findings were the same as the previous pelvic mass; however, positive staining for PSA was observed only in the prostate mass. This case demonstrates a patient with prostate cancer and negative serological test and tissue staining that turned out to be positive during progression. We suggest the usefulness of newly developed immunohistochemical markers such as P504S to determine the specific primary site of metastatic poorly differentiated adenocarcinoma in men.
Cho
Jung Yeon
JY
Department of Internal Medicine, School of Medicine, Ewha Womans University, Seoul, Korea.
Shim
Eun Jin
EJ
Kim
In Seon
IS
Nam
Eun Mi
EM
Choi
Moon Young
MY
Lee
Kyung Eun
KE
Mun
Yeung Chul
YC
Seoung
Chu Myoung
CM
Lee
Soon Nam
SN
Song
Dong Eun
DE
Han
Woon Sup
WS
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