Prostate cancer (PCa) is a major health risk for older men worldwide. Existing systemic therapies mostly target androgen receptor (AR). Although treatments are initially effective, the disease always recurs. A potential mechanism for the treatment failure is that PCa contains, in addition to the AR-positive luminal type tumor cells, a small component of neuroendocrine (NE) cells. The function of NE cells in PCa remains poorly understood, and one important characteristic of these cells is their lack of expression of AR and resistance to hormonal therapy. In addition, many patients develop the more aggressive small-cell neuroendocrine carcinoma (SCNC) after hormonal therapy. Although this clinical phenomenon of disease transformation from adenocarcinoma to SCNC is well established, the cell of origin for SCNC remains unclear. Recently, loss of function of Rb and TP53 and amplification and overexpression of MYCN and Aurora A kinase have been identified as important biomarkers and potential disease drivers. In this article, we systematically review the histology of normal prostate and prostate cancer including the main histologic types: adenocarcinoma and SCNC. We also review the findings from many studies using cellular and animal models as well as human specimens that attempt to understand the molecular mechanisms of treatment failure, disease progression, and tumor transformation from adenocarcinoma to SCNC.
Adenocarcinoma/pathology* ; Carcinoma, Small Cell/pathology* ; Humans ; Male ; Neuroendocrine Cells/pathology* ; Prostatic Neoplasms/pathology*

Neuroendocrine cells are abundant in all the body tissues and organs as well as the nervous system, either the central or the peripheral nervous system. In the normal prostate tissue, there are a few neuroendocrine cells, too, in addition to basal and epithelial cells. Prostatic neuroendocrine cells play the function of regulating the development, secretion and differentiation of the prostate. Recent studies show that prostatic neuroendocrine cells may be involved in the pathogenesis of chronic prostatitis through their activity and secreted products. This article presents an overview on the origin, distribution, morphology, structure, secretion and functions of prostatic neuroendocrine cells and their association with chronic prostatitis.
Chronic Disease ; Epithelial Cells ; cytology ; Humans ; Male ; Neuroendocrine Cells ; cytology ; Prostate ; cytology ; Prostatitis ; pathology

Animals ; Carcinoma, Neuroendocrine ; metabolism ; pathology ; physiopathology ; Carcinoma, Small Cell ; metabolism ; pathology ; physiopathology ; Cell Differentiation ; Chromogranin A ; metabolism ; Humans ; Male ; Neuroendocrine Cells ; metabolism ; pathology ; Prostatic Neoplasms ; metabolism ; pathology ; physiopathology

Adenocarcinoma ; pathology ; Adult ; Aged ; Female ; Humans ; Lasers ; Male ; Middle Aged ; Neuroendocrine Cells ; pathology ; Polymerase Chain Reaction ; methods ; Stomach Neoplasms ; pathology

BACKGROUND/AIMS: Neuroendocrine tumors (NETs) may originate from heterogeneous neuroendocrine cells. The incidence is increasing worldwide, and World Health Organization (WHO) updated its classification in 2010. We investigated clinical characteristics of gastroenteropancreatic NETs in a single center. METHODS: Clinicopathologic characteristics of patients with pathologically confirmed gastroenteropancreatic NET in Seoul St. Mary Hospital from March 2009 to August 2011 were retrospectively analyzed. The grade and stage were determined according to WHO 2010 classification and TNM Staging System for Neuroendocrine Tumors (7th ed., 2010) of American Joint Committee on Cancer. RESULTS: One hundred and twenty-five patients (median age, 50; male, 61.3%) were analyzed. Among 100,000 patients who visited the hospital, incidence was 24.1. Only two patients (1.6%) had a functional NET. The rectum (n = 99, 79.8%) was most common primary site and found in early stage. The prevalence by stages was 84.7% stage I, 8.9% stage IV, 4.8% stage II, and 1.6% stage III. The pathology grading was 74.5% grade 1, 12.7% grade 2, and 12.7% grade 3. Tumor stage correlated positively with pathologic grade (Spearman’s rank correlation coefficient, 0.644). CONCLUSIONS: Wide range of clinicopathological features of Korean gastroenteropancreatic NETs were demonstrated using WHO 2010 classification. Rectal NET was most frequent and found in early stage.
Classification ; Epidemiology ; Humans ; Incidence* ; Joints ; Korea* ; Male ; Neoplasm Staging ; Neuroendocrine Cells ; Neuroendocrine Tumors* ; Pathology ; Prevalence ; Rectum ; Retrospective Studies ; Seoul ; World Health Organization

BACKGROUND/AIMS: Neuroendocrine tumors (NETs) may originate from heterogeneous neuroendocrine cells. The incidence is increasing worldwide, and World Health Organization (WHO) updated its classification in 2010. We investigated clinical characteristics of gastroenteropancreatic NETs in a single center. METHODS: Clinicopathologic characteristics of patients with pathologically confirmed gastroenteropancreatic NET in Seoul St. Mary Hospital from March 2009 to August 2011 were retrospectively analyzed. The grade and stage were determined according to WHO 2010 classification and TNM Staging System for Neuroendocrine Tumors (7th ed., 2010) of American Joint Committee on Cancer. RESULTS: One hundred and twenty-five patients (median age, 50; male, 61.3%) were analyzed. Among 100,000 patients who visited the hospital, incidence was 24.1. Only two patients (1.6%) had a functional NET. The rectum (n = 99, 79.8%) was most common primary site and found in early stage. The prevalence by stages was 84.7% stage I, 8.9% stage IV, 4.8% stage II, and 1.6% stage III. The pathology grading was 74.5% grade 1, 12.7% grade 2, and 12.7% grade 3. Tumor stage correlated positively with pathologic grade (Spearman’s rank correlation coefficient, 0.644). CONCLUSIONS: Wide range of clinicopathological features of Korean gastroenteropancreatic NETs were demonstrated using WHO 2010 classification. Rectal NET was most frequent and found in early stage.
Classification ; Epidemiology ; Humans ; Incidence* ; Joints ; Korea* ; Male ; Neoplasm Staging ; Neuroendocrine Cells ; Neuroendocrine Tumors* ; Pathology ; Prevalence ; Rectum ; Retrospective Studies ; Seoul ; World Health Organization

Merkel cell carcinoma (MCC) is a rare neuroendocrine tumor of the skin initially believed to arise from the Merkel cells. In the community setting a general radiation oncologist may only encounter this pathology in a handful of cases over the course of their career. Due to the low incidence of this malignancy, few prospective randomized controlled trials have ever been conducted and therefore guidelines are based on relatively lower levels of evidence upon which the clinical recommendations are made. We discuss the case of a female in her 90s presenting with a classic MCC primary lesion, as well as satellite lesions proximal to both the primary and the draining regional lymph nodes with no evidence of nodal involvement. Here we discuss the presentation, management, treatment planning, underlying pathology, results and sequelae of treatment. We also review new treatment modalities, and the most current staging systems and guidelines.
Carcinoma, Merkel Cell ; Female ; Hand ; Humans ; Incidence ; Lymph Nodes ; Merkel Cells ; Neuroendocrine Tumors ; Pathology ; Prospective Studies ; Skin

BACKGROUND/AIMS: Pancreatic neuroendocrine tumors (PNET) are rare and manifest as functioning tumor (FT) or non-functioning tumor (NFT). Although malignant changes are observed in some cases, its prognosis is better than pancreatic cancer. We evaluated clinicoradiologic features and prognosis of FT and NFT. In addition, we tried to find the predictive factors for the recurrence of NFT after resection. METHODS: Between October 1994 and June 2004, we retrospectively evaluated the clinicopathologic features and prognosis of 12 cases of FT and 31 cases of NFT diagnosed by surgical pathology at single medical center in Korea. RESULTS: PNET included 6 insulinomas, 4 gastrinomas, 1 glucagonoma, 1 somatostatinoma and 31 NFT. The major clinical manifestations were neuroglycopenic symptoms (100%) in insulinoma, abdominal ulcer symptoms (75%) in gastrinoma, dermatitis (100%) in glucagonoma, steatorrhea (100%) in somatostatinoma, and abdominal discomfort or pain (45%) in NFT. NFT was located more proximally when compared to FT (p=0.023). NFT showed more malignant (64.5%) behavior compared to FT (41.7%) despite the lack of statistical significance. Curative resections were done without postoperative death in 38 cases. Six cases of NFT (21.4%) and 1 case of FT (10%) recurred with an average of 26.5 months. In the recurrent NFT, the findings of diabetes mellitus (p=0.010), abnormal pancreatic duct (p=0.026), Whipple's operation (p=0.013) and tumor emboli (p=0.03) were more common than in non-recurrent NFT. CONCLUSIONS: FT and NFT showed different clinicoradiologic features. In addition, NFT should be monitored more carefully because of frequent recurrence.
Adult ; Diabetes Mellitus/pathology ; Female ; Humans ; Male ; Middle Aged ; Neoplastic Cells, Circulating/pathology ; Neuroendocrine Tumors/complications/*diagnosis ; Pancreatic Ducts/abnormalities/pathology ; Pancreatic Neoplasms/complications/*diagnosis ; Whipple Disease/complications

OBJECTIVETo study the possible clonal origin of neuroendocrine cells in colorectal adenocarcinoma.

METHODSTwenty-six microsatellite loci were screened using laser capture microdissection, DNA extraction and whole genome amplification. Microsatellite instability (MSI) and loss of heterozygosity (LOH) in adenocarcinoma cells and neuroendocrine cells amongst 30 cases of colorectal carcinoma with neuroendocrine differentiation were detected using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP)-silver staining. The mutation status of p53 was evaluated by PCR-sequencing. The clonal origin of neuroendocrine cells in colorectal adenocarcinoma was determined.

RESULTSAmongst the 30 cases studied, the prevalence of MSI was 16.9% while that of LOH was 8.5%. The rate showed no statistically significant difference between adenocarcinoma cells and neuroendocrine cells. In 6 cases, the microsatellite alteration was entirely consistent. In 23 cases, the rate of microsatellite alteration consistency was greater than that of inconsistency. In 1 case, the consistency and inconsistency rates were identical. There was statistically significant difference between consistency and inconsistency of microsatellite alteration. The prevalence of p53 mutation was 16.7% which was the same for both adenocarcinoma cells and neuroendocrine cells.

CONCLUSIONSAdenocarcinoma cells and neuroendocrine cells in colorectal adenocarcinoma with neuroendocrine differentiation have similar biologic changes. It is likely that they are of identical origin.

Adenocarcinoma ; genetics ; pathology ; Colorectal Neoplasms ; genetics ; pathology ; DNA Mutational Analysis ; Humans ; Laser Capture Microdissection ; Loss of Heterozygosity ; Microsatellite Instability ; Neuroendocrine Cells ; pathology ; Tumor Suppressor Protein p53 ; genetics

Objective: To investigate the clinical features, morphological characteristics, immunophenotype, and differential diagnosis of goblet cell adenocarcinoma (GCA) in the digestive system. Methods: The clinicopathological data, morphological characteristics, immunophenotypes of 22 cases of GCA in the digestive system diagnosed from January 2010 to January 2021 were collected. Meanwhile, 25 cases of neuroendocrine neoplasm (NEN) and 24 cases of adenocarcinoma were used as controls. Relevant literature was also reviewed. Results: There were 16 males and 6 females, aged from 36 to 79 years with an average of 56 years. The anatomical sites of the 22 GCA were mostly appendix (17 cases) and occasionally extra-appendix (5 cases), including 3 cases in stomach, 1 case in duodenum and 1 case in anal. All 17 cases of appendiceal GCA were pure GCA. Among the 5 cases of extra-appendiceal GCA, One case of gastric GCA was pure, two cases of gastric GCA with NEN or adenocarcinoma, duodenal GCA with NEN and adenocarcinoma, anal GCA with NEN.Low-grade GCAs were composed of goblet, Paneth and neuroendocrine cells, which were arranged in intestinal crypt tubular or cluster structures and distributed in the wall of digestive system. The tubular and cluster structures lacked adhesion. Goblet cells were columnar, located in the base, with clear cytoplasm, small nuclei, inconspicuous atypia, and uncommon mitoses. Extracellular mucus and signet-ring cells with nuclear variations could be seen in some cases. Nerve fiber bundle invasion and tumor thrombus in vessels were often present. High-grade GCAs lacked tubular and cluster structures, and their histological structures were more complex. Tumor cells expressed mixed neuroendocrine and glandular epithelial markers. Similar to the expression patterns of synaptophysin and chromogranin A, CD200 and INSM1 were also dot-like or patch-positive in GCA. Conclusions: GCA is an infrequent tumor of the digestive system and shows the bi-directional differentiation characteristics of neuroendocrine and glandular epithelium. Accurate diagnosis and staging are related to its prognosis.
Adenocarcinoma/pathology* ; Appendiceal Neoplasms/surgery* ; Carcinoid Tumor/surgery* ; Chromogranin A ; Female ; Goblet Cells/pathology* ; Humans ; Male ; Neuroendocrine Tumors/pathology* ; Repressor Proteins ; Synaptophysin