Eosinophilic cell change of the endometrium: a possible relationship to mucinous differentiation

Oxyntic Gland Neoplasms - From Adenoma to Advanced Gastric Cancer: A Review of 29 Cases

PURPOSE

Oxyntic gland neoplasm (OGN) is a rare condition that can be classified as oxyntic gland adenoma (OGA) or gastric adenocarcinoma of fundic-gland type (GA-FG). GA-FG primarily presents as early gastric cancer, with only a few reported cases of advanced gastric cancer (AGC). We aimed to investigate the clinicopathological features of OGN and describe an aggressive variant.

MATERIALS AND METHODS

We investigated a total of 29 cases, including a patient with double primary cases, diagnosed with OGN or differentiated-type adenocarcinoma with GA-FG morphology, between November 2016 and April 2022. We analyzed 54 pathological specimens and reviewed their clinicopathological, endoscopic, and histological features. The lesions were reclassified as OGA or GA-FG, and immunohistochemical (IHC) staining for MUC-5AC and MUC-6 was performed on available resected GA-FG cases.

RESULTS

The median patient age was 65 years and males accounted for 58.6% of patients. Most cases occurred in the body horizontally (69.0%) and on the greater curvature side cross-sectionally (48.3%). Endoscopically, type 0-IIa (41.4%) and a subepithelial tumor-like appearance (24.1%) were the most common findings. Histologically, there were 8 cases of OGA (27.6%) and 21 cases of GA-FG (72.4%). In GA-FG, MUC-6 was positive in 13 cases (81.3%), whereas MUC-5AC was positive in 8 cases (50.0%). Three cases presented as AGCs.

CONCLUSIONS

Although OGNs are generally considered low-grade, they can present as AGCs and may exhibit features of lymphovascular or perineural invasion. Recognizing the clinicopathological features and accurately diagnosing OGN are important for providing adequate treatment.

Eosinophilic Metaplasia in the Epididymis in Association With Lipofuscin Pigment: A Case Report

We present the case of a 54-year-old man with a cystic formation measuring 0.6 cm in the head of the epididymis. Histologically, the lesion showed intense granular eosinophilic transformation of the cytoplasm. The finding was assessed as eosinophilic metaplasia (EM) and showed association with and deposition of lipofuscin pigment. The EM in the epididymis presents a sign of intracytoplasmic lysosomal accumulation, which serves as a microscopic indicator of ductal obstruction. The presented unique finding was compared with the data reported in the literature. In this case report, we describe an extremely rare metaplastic lesion in the epididymis.

Primary endometrial gastric (gastro-intestinal)-type carcinoma: A practical approach

The latest WHO classification of the female genital tract tumors introduces a new type of carcinoma: the primary gastric-type (or gastro-intestinal type) carcinoma of the endometrium. This type of neoplasm tends to have a poor outcome, making its correct diagnostic important. As little is known about this entity and given its quite challenging diagnosis, we aim to review existing data about it and propose a practical diagnostic approach. There are currently 11 cases published in 8 articles fitting the precise definition of a primary gastric-type carcinoma of the endometrium. Three main differential diagnoses must be excluded before considering this tumor: endometrioid adenocarcinoma with mucinous (Müllerian-type) differentiation, endocervical primary, and gastro-intestinal primary. Morphological aspects of this tumor can be heterogeneous and confusing; in this context, immunochemistry can be helpful to highlight the gastric or intestinal differentiation, but also to eliminate a mucinous endometrioid adenocarcinoma of Müllerian-type, by the constant negativity of estrogen receptors. A metastasis of a primary gastro-intestinal tract carcinoma must also be excluded by clinical, endoscopic and imaging work-up. Finally, an endometrial extension of a primary endocervical gastric-type carcinoma should be ruled out by complete sampling of the cervix. Intestinal type endocervical adenocarcinoma is easier to eliminate since this is an HPV-associated neoplasm.

Mucinous Proliferations of the Uterine Corpus: Comprehensive Appraisal of an Evolving Spectrum of Neoplasms

A variety of endometrial lesions may contain mucinous cells. Herein, the author reviews the literature on the classification and clinicopathologic significance of uterine corpus proliferations with a significant mucinous component, assesses the 2020 World Health Organization classification of such lesions, and presents a diagnostic framework. The key epithelial mucinous lesions include mucinous metaplasia, atypical mucinous glandular proliferation and mucinous carcinoma. Each of these categories are classifiable into "usual" and gastrointestinal subtypes, the latter being indicative of intestinal (presence of goblet cells) and/or gastric-type (abundant, pale eosinophilic or clear cytoplasm and well-defined cell borders) morphology. It has been proposed that at least focal expression of gastrointestinal immunohistochemical markers be required for all gastrointestinal type lesions, and for gastrointestinal type atypical mucinous glandular proliferation and carcinoma, minimality or absence of estrogen receptor expression, and the absence of an endometrioid component. Mucinous carcinomas of the usual type, in which >50% of the tumor is comprised of a mucinous component, are the most common. Morphologic subtypes include mucinous carcinoma with microglandular features and mucinous carcinoma with signet rings (signet ring carcinoma). Endometrioid carcinomas with a less than a 50% mucinous component are classified as endometrioid carcinoma with mucinous differentiation. Several studies have directly compared endometrioid and mucinous carcinomas, the latter presumably of the usual type, with respect to patient outcomes after treatment. All have found no difference in overall and disease free survival between these groups. However, three major studies have found mucinous carcinomas to be associated with a higher risk of lymph node metastases. Nineteen cases of mucinous carcinoma of the gastrointestinal type have been reported, and the limited data on their follow-up after primary treatment suggests that this subtype is more clinically aggressive and should accordingly be classified separately from mucinous carcinomas of the usual type. The morphologic spectrum of mucinous carcinoma of the gastrointestinal type is unclear and continues to evolve. Mucinous change, which may sometimes be extensive, may also be associated with papillary proliferation of the endometrium, adenomyoma of the endocervical type, atypical, and typical adenomyomas. In a curettage or biopsy, intestinal type mucinous epithelium may be indicative of any of the gastrointestinal lesions mentioned above, but may also represent samplings of uterine teratomas, yolk sac tumors, genital and extragenital adenocarcinomas with intestinal differentiation, or low-grade appendiceal mucinous neoplasms that secondarily involve the endometrium.

[Precursor lesions of endometrial carcinoma]

The 2014 WHO classification distinguishes between endometrial hyperplasia without atypia (EH) and atypical endometrial hyperplasia/endometrioid intraepithelial neoplasia (AEH/EIN). AEH/EIN is characterized by crowded glands with cytologically atypical epithelium separated by little intervening stroma. Cellular atypia is characterized by nuclear enlargement and rounding, pleomorphism, loss of polarity, and presence of nucleoli. The diagnosis of atypia is facilitated by comparison with areas of adjacent normal and non-atypical glands, respectively. AEH/EIN is often associated with squamous but also secretory and mucinous metaplasia. Loss of PTEN and/or PAX2 immunoreactivity occurs in up to two thirds of AEH/EIN. In contrast, invasive low-grade endometrioid carcinoma shows confluent growth with loss of stroma and formation of labyrinth-like or cribriform structures. Differential diagnosis includes different forms of metaplasias, papillary proliferations, and hyperplastic polyps. Epithelial metaplasia may be present in various benign endometrial lesions as well as in endometrioid adenocarcinoma. AEH/EIN may also occur in endometrial polyps. Progestin therapy of AEH/EIN has low level of evidence but frequently leads to complete regression. Serous intraepithelial carcinoma (SEIC) is characterized by high-grade cellular atypia and polymorphism, detachment of cells, a mutant immunoreactive pattern for the P53 and an increased Ki67 labeling index. Although designated as precursor of serous carcinoma of the endometrium, biologically it is considered a non-invasive serous carcinoma since it may already be associated with massive extrauterine spread.

Expression of MUC1 in eosinophilic metaplasia of the prostate

BACKGROUND

Eosinophilic metaplasia (EM) in the prostate is characterized by the presence of eosinophilic cytoplasmic granules in benign prostatic epithelium. These granules show exocrine-type morphology and positive expression for prostate specific antigen (PSA) and some lysosomal markers. The nature and the full immunohistochemical profile of the granules of EM have not been studied in detail yet.

AIM

The aim of the current study is to investigate the expression of epithelial mucins (MUCs) in prostatic epithelium with EM.

METHODS

Twenty specimens from transurethral resection of the prostate (TURP) were reviewed for the presence of EM and were stained with Periodic acid-Schiff's procedure with diastase digestion (PAS.D) and immunostained with PSA and MUCs: MUC1, MUC2, MUC5AC, and MUC6.

RESULTS

The EM-foci of all prostate glands are PAS.D, PSA positive and show constant immunoreactivity for MUC1. The expression of MUC1 is with membranous and cytoplasmic localization: predominantly apical with membranous accentuation in the cases of EM with large eosinophilic granules, and perinuclear in EM with small eosinophilic granules. There is no expression of other MUCs (MUC2, MUC5AC, and MUC6) in prostatic EM.

CONCLUSION

We report for the first time that eosinophilic cytoplasmic granules in prostatic EM are MUC1 positive and can vary in size. Based on our immunohistochemical study we suggest that EM of the prostate is not a form of mucinous metaplasia. The present results enrich the available information about the immunophenotype of EM. We assume that MUC1 might serve as a reliable and constant, although nonspecific, immunohistochemical marker of benign EM-phenotype.

Mucinous metaplasia of the endometrium: current concepts

OBJECTIVES

The objective of this review was to discuss the highly variable terminology describing mucinous metaplasia of the endometrium, histologic features and characteristic findings by special stains and immunohistochemistry, differential diagnostic challenges, current treatment and prognosis.

METHODS

A review of the literature was performed on mucinous metaplasia of the endometrium.

RESULTS

Mucinous metaplasia is an uncommon type of endometrial epithelial metaplasia, often associated with hyperestrogenic states or hormone replacement therapy. Histologic findings range from simple endocervical-type mucinous epithelium to architecturally complex mucinous proliferations. Mucinous metaplasia often presents a significant diagnostic challenge in endometrial biopsies and should be differentiated from endocervical microglandular hyperplasia, and mucinous or mixed mucinous and endometrioid carcinomas. Simple mucinous metaplasia is believed to have a low risk of associated carcinoma, whereas architecturally complex cases often show invasive malignancy on subsequent biopsy.

CONCLUSIONS

Complex mucinous proliferations should be managed with dilatation and curettage and repeat biopsy within 6months, and strong consideration should be given to a hysterectomy in persistent mucinous proliferations.

Microarray Analysis of Gene Expression in the Uterine Endometrium during the Implantation Period in Pigs

During embryo implantation in pigs, the uterine endometrium undergoes dramatic morphological and functional changes accompanied with dynamic gene expression. Since the greatest amount of embryonic losses occur during this period, it is essential to understand the expression and function of genes in the uterine endometrium. Although many reports have studied gene expression in the uterine endometrium during the estrous cycle and pregnancy, the pattern of global gene expression in the uterine endometrium in response to the presence of a conceptus (embryo/fetus and associated extraembryonic membranes) has not been completely determined. To better understand the expression of pregnancy-specific genes in the endometrium during the implantation period, we analyzed global gene expression in the endometrium on day (D) 12 and D15 of pregnancy and the estrous cycle using a microarray technique in order to identify differentially expressed endometrial genes between D12 of pregnancy and D12 of the estrous cycle and between D15 of pregnancy and D15 of the estrous cycle. Results showed that the global pattern of gene expression varied with pregnancy status. Among 23,937 genes analyzed, 99 and 213 up-regulated genes and 92 and 231 down-regulated genes were identified as differentially expressed genes (DEGs) in the uterine endometrium on D12 and D15 of pregnancy compared to D12 and D15 of the estrous cycle, respectively. Functional annotation clustering analysis showed that those DEGs included genes involved in immunity, steroidogenesis, cell-to-cell interaction, and tissue remodeling. These findings suggest that the implantation process regulates differential endometrial gene expression to support the establishment of pregnancy in pigs. Further analysis of the genes identified in this study will provide insight into the cellular and molecular bases of the implantation process in pigs.

Endometrial intraepithelial neoplasia

CONTEXT

Developed in conjunction with molecular and progression data, the sequence classification schema for endometrial intraepithelial neoplasia (EIN)/benign hyperplasia (BH) provides an easy to adopt and reproducible method for classification of endometrial biopsies.

OBJECTIVE

To review current data supporting the use of BH/EIN to classify endometrial biopsies, and to discuss the hormone-driven endometrial sequence from anovulation/disordered proliferative endometrium through BH and EIN and their diagnostic difficulty.

DATA SOURCES

A comprehensive review of EIN literature based on literature indexed by PubMed (National Library of Medicine) and Google Scholar.

CONCLUSIONS

The BH/EIN schema is gaining wider acceptance among pathologist and clinicians. The research leading to the EIN criteria is based on molecular and progression data. The BH/EIN schema has better reproducibility among pathologists, is intuitively easy to use, and requires understanding of endometrial physiology and neoplasia.

Endometrial intraepithelial neoplasia is associated with polyps and frequently has metaplastic change

AIMS

Endometrial intraepithelial neoplasia (EIN) is a monoclonal precursor to endometrioid endometrial adenocarcinoma characterized by a geographic cluster of crowded glands with epithelial cytology altered relative to the background. It may demonstrate epithelial metaplastic changes, or arise within polyps, but the frequencies of these features as encountered in practice is unknown. The aim was to report the epithelial differentiation state and polyp context of 83 sequential EIN lesions diagnosed over a 2-year period.

METHODS AND RESULTS

EIN is a rare lesion, seen in only 1.4% of endometrial biopsy specimens in a busy hospital-based practice. Of 83 EIN cases, 39 contained metaplastic changes (18% squamous morular, 14% tubal secretory and 5% each of secretory, mucinous or ciliated change). Endometrial polyps were more likely (odds ratio 5.2, P < 0.001) to occur in the endometrial biopsy specimens of women with EIN lesions (43.3%), compared with the background polyp rate (12.9%) of comparable specimens from the same patient population.

CONCLUSIONS

Non-endometrioid differentiation and occurrence within polyps are frequent presentations of EIN lesions. Possible mechanisms of polyp association with EIN include: non-shedding of polyp tissue creating a shelter for persistence of pre-existing neoplastic glands, or promotion of premalignant glandular clones by unique polyp stroma.