Neuroendocrine differentiation of periodic-acid Schiff and Alcian blue-negative signet-ring cell-like cells and tubular adenocarcinoma cells within a gastric cancer

Colloid Carcinoma Arising in an Intestinal-Type Intraductal Papillary Mucinous Neoplasm with High-Grade Dysplasia Appearing as Signet-Ring Cells of the Pancreas by Serial Pancreatic Juice Aspiration Cytology: A Case Report

We report a case of colloid carcinoma (CC) arising from an intestinal-type intraductal papillary mucinous neoplasm with high-grade dysplasia (IPMNHGD) of the pancreas, diagnosed with serial pancreatic juice aspiration cytological examination (SPACE). A rapidly growing intraductal papillary mucinous neoplasm (IPMN) in a 71-year-old Japanese man accelerated his hospitalization in our institute. Clinically, a large, ruptured pancreatic cyst was suspected. Cytologically, several mucin-positive signet-ring cells were scattered in the inflammatory, necrotic, or mucinous background. Signet-ring cells in cell block specimens were immunoreactive for MUC2, MUC5AC, maspin, S100P, and claudin-18. The final cytologic diagnosis was CC arising in an intestinal-type IPMNHGD with intraperitoneal penetration. The patient died two months after an explorative laparotomy. The cytologic diagnosis was achieved through SPACE, and the presence of signet-ring cells was characteristic. Anti-claudin-18.2-specific monoclonal antibody therapy will likely be used to treat patients with IPMNHGD in the future. This case highlights the diagnostic utility of SPACE, with particular emphasis on the characteristic presence of signet-ring cells. Furthermore, it anticipates the potential use of anti-claudin-18.2- specific monoclonal antibody therapy in the management of IPMNHGD patients.

HER-2-positive primary neuroendocrine neoplasms of the breast with signet ring feature: A case report and review of literature

Background

Primary neuroendocrine neoplasm of the breast (BNEN) is an uncommon breast neoplasm, and in most cases, it presents as hormone receptors positive and HER-2 negative. Moreover, in neuroendocrine neoplasms (NENs), the signet ring feature is a rare morphological subtype, and only a few cases have been reported. Here, we report the case of a primary breast neuroendocrine neoplasm with an unusual signet ring cell appearance in this paper. The documentation of this case, combined with a review of the literature, may add to existing knowledge about the outcome and management of this rare tumor.

Methods

In the present review, we describe a unique case of HER-2-positive primary BNEN with a signet ring feature that has not been reported in English. Additionally, we performed a literature search of the PubMed and Web of Science databases and calculated statistics for clinical data and follow-up.

Results

Our literature search, excluding non-English literature, identified 15 articles with data from 24 cases, including ours. The mean age was 51.25 years (range, 30-79 years), and there were 13 male patients (54%) and 11 female patients (46%). Of the 24 cases, some cases (11/24) were associated with lymph node metastases, a few cases (6/24) had distant metastasis, and the vast majority of cases (23/24) occurred in the digestive system. Primary hepatic signet ring cell neuroendocrine tumor showed slow progression and good prognosis. Lymph node involvement was identified in one of eight (12.5%) documented cases, and one of eight (12.5%) reported cases presented with distant metastatic disease. However, the prognosis of neuroendocrine tumors with signet ring cells in the pancreas and stomach was poor. Lymph node involvement was identified in 9 of 15 (60%) documented cases, and 5 of 15 (33.3%) reported cases presented with distant metastatic disease.

Conclusion

NENs with a signet ring feature is uncommon, and this is the first case report of its occurrence in the breast. Current knowledge is limited to anecdotal experience based on case reports and small case series. We provide a literature review to summarize knowledge about this rare entity.

Tumor Classification Should Be Based on Biology and Not Consensus: Re-Defining Tumors Based on Biology May Accelerate Progress, An Experience of Gastric Cancer

Simple Summary

Rational treatment of diseases including cancers depends on knowledge of their cause as well as their development. The present review is based upon more than 40 years’ work in clinical gastroenterology, gastric physiology, and pathology. The central role of hormones as well as local endocrine cells in cancer development has become apparent. Moreover, the classification of tumors should focus not only on the organ of origin but also on the cell of origin. All cells with the ability to divide may give rise to tumors. Based upon knowledge of the growth regulation of the cell of origin, prophylaxis and treatment may be tailored. Presently, there is hope for individual treatment of cancer patients based upon genetic analyses of tumors. However, with correct identification of the cell of origin, this may not be necessary.

Abstract

Malignant tumors are a consequence of genetic changes mainly occurring during cell division, sometimes with a congenital component. Therefore, accelerated cell divisions will necessarily predispose individuals, whether due to conditions of chronic cell destruction or hormonal overstimulation. It has been postulated that two genetic hits are necessary for the development of malignancy (Knudson). The correct view is probably that the number of genetic changes needed depends on the role the mutated genes have in proliferation and growth control. Hormones should accordingly be regarded as complete carcinogens. In this review based upon experience of gastric cancer where gastrin is central in the pathogenesis, it is argued that oxyntic atrophy—and not metaplasia as postulated by Correa—is the central precancer change in gastric mucosa. Moreover, the target cell of gastrin, the enterochromaffin-like (ECL) cell, is central in gastric carcinogenesis and most probably the cell of origin of gastric carcinomas of the diffuse type according to Lauren (a classification probable in accordance with biology). The distinction between adenocarcinomas and neuroendocrine carcinomas based upon a certain percentage of cancer cells with neuroendocrine differentiation is questioned. To make progress in the treatment of cancer, a correct classification system and knowledge of the pathogenesis are necessary.

Neuroendocrine and mucinous differentiation in signet ring cell carcinoma of the stomach: evidence for a common cell of origin in composite tumors

Composite tumors are rare neoplasms containing a mixture of 2 different cellular components present in roughly equal proportions. It is hypothesized that composite tumors arise from a multipotential stem cell with subsequent bidirectional differentiation. We present an unusual composite tumor of the stomach composed equally of signet ring cell carcinoma and low-grade neuroendocrine carcinoma. Twenty-one additional patients with signet ring cell carcinomas of the stomach were studied to determine the prevalence of neuroendocrine differentiation by morphology and immunohistochemistry for synaptophysin and chromogranin A. Immunohistochemistry for mucins 5AC and 2 was performed to assess for divergent differentiation toward foveolar and intestinal mucin phenotypes, respectively, and to evaluate for any potential relationship with neuroendocrine differentiation. We found morphologic evidence of neuroendocrine carcinoma in 4 (19%) of 21 consecutive signet ring carcinomas. E-cadherin immunostaining was subsequently performed on these 4 tumors plus the index case. All 5 tumors demonstrated concordance between the signet ring and neuroendocrine components. There was no distinct relationship to mucin 5AC/mucin 2 profiles, with the exception that all 11 intramucosal signet ring cell carcinomas from 4 patients with germ line cadherin 1 gene mutations were composed exclusively of mucin 5AC+ signet ring cells that lacked intestinal mucin and neuroendocrine differentiation. The concordant E-cadherin status in the neuroendocrine and signet ring cell tumor components and the frequent admixture of mucin 5AC+ cells with foveolar differentiation and mucin 2+ cells with intestinal differentiation may support the hypothesis that composite tumors arise from a common stem cell with bilineage or multilineage differentiation.

Synchronous occurrence of carcinoid, signet-ring cell carcinoma and heterotopic pancreatic tissue in stomach: A case report and literature review

We presented an unusual case with coexistence of carcinoid, signet-ring cell carcinoma (SRC) and heterotopic pancreatic tissue in stomach. Gastroscopic examination of this 63-year-old male patient showed multiple protrusions in gastric corpus near the greater curvature, identified by subsequent biopsy as carcinoid. Distal subtotal gastrectomy was performed. Histological and immunohistochemical examinations showed a carcinoid tumor in gastric corpus near the greater curvature, an intramucosal SRC at the lesser curvature of corpus and heterotopic pancreatic tissue in muscularis propria of the antrum at the lesser curvature with hyperplasia of peripheral endocrine cells producing multiple pancreatic hormones. We reviewed the literatures on clinicopathological characteristics and the differential diagnosis of the above three abnormalities, and concluded that the carcinoid in corpus near the greater curvature and SRC in the lesser curvature are independent lesions; the foci of endocrine cells in the muscularis propria and serosa are hyperplastic lesions from the heterotopic pancreatic tissue, rather than dissemination of carcinoid in corpus.

Coexistence of carcinoid, signet-ring cell carcinoma and heterotopic pancreas in stomach: a clinicopathological observation

AIM: To report a case with synchronous occurr-ence of carcinoid, signet-ring cell carcinoma (SRC) and heterotopic pancreas in stomach.

METHODS: One male patient aged 63 years old was diagnosed with coexistence of carcinoid, signet-ring cell carcinoma and heterotopic pancreas in stomach by gastroscopy and pathological examination. These three lesions were further observed by histopathological, histochemical and immunohistochemical approaches, with the related literatures reviewed.

RESULTS: Multiple foci of proliferative endocrine cells were found in lamina propria of the corpus, and carcinoid was found in corpus on the greater curve of the stomach, with muscularis mucosae involved. The tumor cells were strongly positive for neuron-specific enolase, synaptophysin and chromogranin A. An intramucosal SRC lesion was found in the lesser curve of corpus. Heterotopic pancreatic tissue was observed in muscularis propria of the antrum on the lesser curve, with hyperplasia of endocrine cells producing multiple pancreatic hormones.

CONCLUSION: Carcinoid in corpus of the greater curve and SRC in the lesser curve are independent lesions; the foci of endocrine cells in the muscularis propria and serosa are hyperplastic lesions from the heterotopic pancreatic tissue, rather than carcinoid dissemination.

Signet ring cells in gastric carcinomas are derived from neuroendocrine cells

Adenocarcinomas are malignant tumors with glandular growth and/or supposed intracellular mucin as identified by periodic acid-Schiff (PAS) positivity. Gastric signet ring cell carcinomas are classified as diffuse type. A proportion of diffuse-type adenocarcinomas have previously been suggested to be of neuroendocrine origin. In the present study we examined gastric signet ring cell carcinomas for neuroendocrine differentiation. Of 11 gastric signet ring cell carcinomas, 8 contained areas with PAS-positive signet ring cells that also were immunoreactive for one or several neuroendocrine markers: synaptophysin, chromogranin A, and histidine decarboxylase, the latter an enterochromaffin-like (ECL) cell marker. Whereas PAS positivity was located in the central cytoplasm, neuroendocrine immunoreactivity was often located as a rim surrounding an otherwise non-immunoreactive cytoplasm, presumed to represent the area with PAS-positive material. These findings indicate that signet ring cell carcinomas could be of neuroendocrine origin. We propose that signet ring cell carcinomas develop by gradual dedifferentiation from ECL cells via signet ring cells with neuroendocrine immunoreactivity toward signet ring cells where the cytoplasm mainly consists of PAS-positive material. This finding could have implications for the classification and understanding of gastric carcinogenesis.