Unusual and underappreciated: small cell carcinoma of the prostate.

Neuroendocrine tumors are more common in the female than male genital tract; most are uterine small cell carcinomas or ovarian carcinoids. Primary ovarian carcinoids are divided into insular, trabecular, strumal, and mucinous types; most are benign. Carcinoids metastatic to the ovary are more aggressive; most arise in the gastrointestinal tract. Scattered neuroendocrine cells are seen in a variety of ovarian surface epithelial tumors; sporadic mucinous cystic tumors with neuroendocrine cells have been associated with Zollinger-Ellison syndrome. Frank neuroendocrine carcinomas in the ovary include small cell carcinoma and large cell neuroendocrine carcinoma, each with a poor prognosis and often associated with a conventional surface epithelial tumor Such carcinomas also occur in the endometrium and cervix. Uterine carcinoids are rare if strict criteria are applied. Small cell neuroendocrine carcinomas also occur rarely in the vagina and vulva. Most male genital tract neuroendocrine tumors are prostatic small cell carcinomas or testicular carcinoids. Extragonadal carcinoids of the male genital tract are rare. Testicular carcinoids should be distinguishedfrom metastatic tumors. It is important to distinguish prostatic small cell carcinoma from poorly differentiated adenocarcinoma with small cells. Small cell neuroendocrine carcinomas also occur rarely in the scrotum, penis, and penile urethra.

Neuroendocrine tumors of the genital tract.

Objective To evaluate the cancer detection rate of whole-body positron emission tomography–computed tomography (PET-CT) in a paraneoplastic neurologic context. Design Retrospective medical record review. Setting Mayo Clinic, Rochester, Minnesota. Patients Fifty-six consecutive patients with clinically suspected paraneoplastic neurologic disorders who underwent PET-CT after negative standard evaluations, including CT. Main Outcome Measure Rate of cancer detection. Results Abnormalities suggestive of cancer were detected using PET-CT in 22 patients (39%); 10 patients (18%) had cancer confirmed histologically. Cancers detected (limited stage in 9 of 10 patients and extratruncal in 4) were as follows: 2 thyroid papillary cell carcinomas, 3 solitary lymph nodes with unknown primary (2 adenocarcinomas and 1 small cell carcinoma), 1 tonsil squamous cell carcinoma, 3 lung carcinomas (1 adenocarcinoma, 1 small cell, and 1 squamous cell), and 1 colon adenocarcinoma. Detection of a well-characterized neuronal nuclear or cytoplasmic paraneoplastic autoantibody was associated with a successful PET-CT–directed cancer search ( P Conclusion In a paraneoplastic neurologic context, PET-CT improves the detection of cancers when other screening test results are negative, particularly in the setting of seropositivity for a neuronal nuclear or cytoplasmic autoantibody marker of cancer. Published online January 11, 2010 (doi:10.1001/archneurol.2009.336).

https://jamanetwork.com/journals/jamaneurology/articlepdf/799566/noc90091_322_329.pdf

Positron Emission Tomography–Computed Tomography in Paraneoplastic Neurologic Disorders: Systematic Analysis and Review

Background: The progression to endocrine therapy-resistant prostate cancer is partly due to clonal change to neuroendocrine cell tumor. To elucidate this pathologic process, the clinical courses of four cases of neuroendocrine cell tumor that were found at autopsy are reported.



Methods: Between 1995 and 1999, autopsies were performed for 20 cases of prostate cancer. Lesions predominantly composed of a neuroendocrine cell tumor (small cell carcinoma) were found in four men. The clinical courses of these cases were compared to 16 other non-neuroendocrine cell tumors (adenocarcinomas).



Results: The outstanding features of the neuroendocrine cell tumors were: (i) survival was brief after relapse, although the duration of control by employing endocrine therapy varied; (ii) the prostate-specific antigen level did not increase after relapse; and (iii) the sites of metastasis were similar to those of common adenocarcinomas.



Conclusion:

The progression to a neuroendocrine cell tumor indicated a poor prognosis and slight (if any) changes in the serum prostate-specific antigen level. This tumor might not appear to respond to any therapeutic attempt.

https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.1442-2042.2001.00347.x

Progression of prostate cancer to neuroendocrine cell tumor.

To investigate the histogenesis of undifferentiated carcinoma of the prostate with small cell features we analysed the expression of neuroendocrine (NE) markers, the androgen receptor (AR), and prostatic-specific antigen (PSA) in 19 undifferentiated carcinomas of the prostate. The proliferative activity (MIB-1/Ki67) of the tumours was examined, and the clinical data reviewed. The results identified two groups: carcinomas in group 1 were positive for PSA and AR and negative for NE markers. The mean MIB-1 labelling index (LI) was 34.8% and the mean serum PSA value 56.4 ng/ml. Two of the 7 patients died within 12 months after tumour diagnosis. The tumours in group 2 were NE differentiated small cell carcinomas (SCC), which were negative for PSA and AR. The mean MIB-1 LI was 82.6% and the mean serum PSA value 7.1 ng/ml. Seven of the 10 patients died between 2 and 12 months after tumour diagnosis. Positive staining for NE markers in combination with negative staining for PSA and AR and a high MIB-1 LI substantiated the diagnosis of a NE-SCC. We suggest that this tumour has a stem cell origin and does not derive from a dedifferentiated adenocarcinoma or from benign NE cells of the prostatic epithelium. This clear distinction of NE-SCC from NE-negative undifferentiated carcinoma is in accordance with the differing biological behaviour and response to therapy of the two tumour entities.

Undifferentiated carcinoma of the prostate with small cell features: immunohistochemical subtyping and reflections on histogenesis.

Primary small cell carcinoma of the prostate is rare. A case of primary small cell prostate cancer treated with radiation and chemotherapy is presented, and 33 previously published case reports are reviewed. Most of the patients (61%) had mixed tumors (small cell and adenocarcinoma) at diagnosis or had a history of adenocarcinoma of the prostate. Prostate specific antigen (PSA) data was available in 11 patients and was abnormal in 4 (36%). Once small cell carcinoma was diagnosed, 70% of patients had metastatic disease. Visceral metastases were common. Only one of seven patients responded to hormonal therapy, and two of eight patients responded to chemotherapy. Overall prognosis was poor.

Aygun C

Papers

Small cell carcinoma of the prostate: a case report and review of the literature.