Elevated prostate markers in metastatic small cell carcinoma of unknown primary

Abstract

Numerous ectopic hormones and markers have been described in small cell carcinoma of the lung as well as in extrapulmonary small cell carcinomas. The authors report a case of a patient with metastatic small cell carcinoma of unknown primary who had very high prostatic acid phosphatase (PAP) and prostatic specific antigen (PSA) levels. Results of multiple prostate examinations, as well as blind biopsies, were normal. His course was significantly longer than that of the usual patient with extensive small cell carcinoma. At autopsy the prostate showed only mild benign prostatic hypertrophy. There are no previous reports in the literature of abnormal prostate markers in small cell carcinomas. Physicians should be aware of the increasing complexity and the unusual biologic markers associated with neuroendocrine carcinomas. In some of these cases, the tumors ability to produce an ectopic product may portend an improved prognosis.

Cutaneous metastasis of prostatic adenocarcinoma: a cautionary tale

“…Of note, poorly differentiated neuroendocrine carcinoma and pulmonary small cell carcinoma may, rarely, express PSA or PAP 10 . In our case, a neuroendocrine neoplasm was excluded by negative immunohistochemical staining for neural cell adhesion molecule (CD56), chromogranin, and synaptophysin.…”

“…9 Of note, poorly differentiated neuroendocrine carcinoma and pulmonary small cell carcinoma may, rarely, express PSA or PAP. 10 In our case, a neuroendocrine neoplasm was excluded by negative immunohistochemical staining for neural cell adhesion molecule (CD56), chromogranin, and synaptophysin. Therefore, an immunohistochemical panel including PSA, PAP and possibly a neuroendocrine marker is recommended in establishing the diagnosis of metastatic prostatic adenocarcinoma.…”

A Case of Advanced Submandibular Gland Cancer in Which Increased Prostate-Specific Antigen and Multiple Bone Metastases Wrongly Suggested Concurrent Prostate Cancer

“…However, Fan et al [ 7 ] reported that immunostaining of SDC was positive for PSA in 2 of 13 cases. In addition, rare cases of increased serum PSA in association with extrapulmonary small cell carcinoma, renal cell carcinoma, lung adenocarcinoma, or periurethral gland carcinoma have been reported [ 2 , 3 , 4 , 5 ]. Also, SDC can be HER2-positive, though negative in the present case; and in the treatment of patients with HER2-positive SDC, add-on trastuzumab to a taxane anticancer agent has been reported to prolong survival, compared with taxane monotherapy [ 8 , 9 ].…”

“…Serum prostate-specific antigen (PSA), a single-chain glycoprotein with a molecular weight of 30 kDa, is a serine protease highly specific for prostate diseases, and widely used as a tumor marker of prostate cancer [ 1 ]. PSA is also known to rarely increase in patients with cancers other than prostate cancer, although several case reports have been published [ 2 , 3 , 4 , 5 ]. This report describes our recent experience with a case of advanced submandibular gland cancer in which increased PSA and multiple bone metastases were misleading and impaired accurate staging and prompt initiation of chemotherapy.…”

A Case of Robot-Assisted Laparoscopic Radical Prostatectomy in Primary Small Cell Prostate Cancer

“…In the urological system, there have been case reports in the kidney, bladder, and prostate [5]. Small cell cancer of the prostate is known to occur as the result of changes in the argyrophil cells and argentaffin cells that exist in the normal prostate [6].…”