Aberrant expression of TFF1, TFF2, and PDX1 and their diagnostic value in lobular endocervical glandular hyperplasia

LGR5-Expressing Cells in the Healing Process of Post-ESD Ulcers in Gastric Corpus

BACKGROUND

LGR5 is a promising stem cell marker in gastric pylorus, but there are few reports on its expression in human gastric corpus.

AIMS

To investigate the involvement of LGR5 expression in gastric corpus ulcer regeneration in humans.

METHODS

LGR5 expression was analyzed in five post-ESD ulcers during the healing process of regenerating epithelial cells of the gastric corpus. LGR5 expression was detected by mRNA in situ hybridization using an RNA scope kit. Immunohistochemistry of MUC6, HIK1083, and pepsinogen 1 (PG1) was performed to identify cell differentiation.

RESULTS

We defined MUC6+/HIK1083-/PG1-, MUC6+/HIK1083+/PG1-, MUC6+/HIK1083+/PG1+, MUC6+/HIK1083-/PG1+, and MUC6-/HIK1083-/PG1+cells as pseudopyloric mucosa (PPM) phase 1 (PPM1), PPM phase 2 (PPM2), PPM phase 3 (PPM3), immature chief cells (ICC), and mature chief cells (MCC) in order from the ulcer center, respectively. In the regenerated mucosa around post-ESD ulcers, LGR5 expression was observed throughout the gland in PPM1-PPM3, but it was limited to the bottom of the gland in ICC and MCC. Furthermore, LGR5 expression was not identified in the normal gastric corpus. The H-score of PPM2 was significantly higher than that of PPM3 (P = 0.0313). The H-score of PPM3 was significantly higher than that of ICC (P = 0.0313). The LGR5 H-score was higher at the immature stage, which decreased gradually with progression of the differentiation stage.

CONCLUSIONS

LGR5 expression appears to contribute to mucosal regeneration in the human gastric corpus. The application of LGR5 expression analysis to mucosal regeneration and fundic gland-type gastric tumors is expected.

Clinicopathological and prognostic significance of immunophenotypic characterization of endocervical adenocarcinoma using CLDN18, CDH17, and PAX8 in association with HPV status

In 2020, the WHO published a new system for classifying invasive endocervical adenocarcinoma based on histological features and high-risk human papillomavirus (HPV) infection. However, immunophenotypes of each histological subtype require further investigation. We immunohistochemically analyzed 66 invasive endocervical adenocarcinomas using three cell-lineage-specific markers: claudin 18 (CLDN18) for gastric, cadherin 17 (CDH17) for intestinal, and PAX8 for Müllerian epithelial cells. We identified five immunophenotypes of endocervical adenocarcinoma: gastric (21%); intestinal (14%); gastrointestinal (11%); Müllerian (35%); and not otherwise specified (NOS) (20%). Adenocarcinomas with gastric immunophenotype, characterized by aging (p = 0.0050), infrequent HPV infection (p < 0.0001), concurrent lobular endocervical glandular hyperplasia (p = 0.0060), lymphovascular invasion (p = 0.0073), advanced clinical stage (p = 0.0001), and the poorest progression-free (p < 0.0001) and overall (p = 0.0023) survivals, were morphologically compatible with gastric-type adenocarcinoma of the WHO 2020 classification. Conversely, most adenocarcinomas with Müllerian (91%) and intestinal (89%) immunophenotypes were HPV associated and morphologically compatible with usual- or intestinal-type adenocarcinomas of the WHO 2020 classification. The morphology of adenocarcinomas with gastrointestinal immunophenotype was intermediate or mixed between those of gastric and intestinal immunophenotypes; 57% were HPV associated. Adenocarcinomas with NOS immunophenotype were mainly HPV associated (85%) and histologically poorly differentiated. Multivariate analysis revealed that gastric (p = 0.008), intestinal + gastrointestinal (p = 0.0103), and NOS (p = 0.009) immunophenotypes were independent predictors of progression-free survival. Immunophenotypes characterized by CLDN18, CDH17, and PAX8 exhibited clinicopathological relevance and may improve the diagnostic accuracy and prognostic value of conventional histological classification.

Trefoil factor family 2 protein: a potential immunohistochemical marker for aiding diagnosis of lobular endocervical glandular hyperplasia and gastric-type adenocarcinoma of the uterine cervix

Gastric-type adenocarcinoma (GA) is an aggressive subtype of cancer of the uterine cervix. Several immunohistochemical markers for gastric mucins, such as mucin 6 (MUC6) and N-acetylglucosamine α1 → 4galactose → R (αGlcNAc-R), which is recognized by HIK1083 antibody, have been introduced for diagnosis of GA and lobular endocervical glandular hyperplasia (LEGH). However, MUC6 is also expressed in normal endocervical glands and HIK1083 antibody has limited availability. Trefoil factor family 2 protein (TFF2) is secreted by gastric, but not normal endocervical glands. Here, we evaluated TFF2 immunostaining for detection of a gastric immunophenotype in endocervical glandular lesions. We compared TFF2, αGlcNAc-R, and MUC6 expression in 103 endocervical glandular lesions: LEGH (n = 23), adenocarcinoma in situ/microinvasive adenocarcinoma (AIS-MIA) (n = 29), and invasive adenocarcinoma (usual type [UA], n = 26; GA, n = 11; intestinal type [IA], n = 2; signet ring cell type [Sig], n = 2; and mucinous adenocarcinoma not otherwise specified [NOS], n = 10). TFF2 and αGlcNAc-R expression was completely concordant in each subtype: LEGH (100%), AIS-MIA (44.8%), UA (26.9%), GA (90.9%), IA (100%), Sig (0%), and NOS (20%). TFF2 staining scores were significantly correlated with those of αGlcNAc-R in these lesions. TFF2 and αGlcNAc-R immunoreactivity was present in cytoplasmic mucins and luminal secretions. TFF2 and αGlcNAc-R were not expressed in the normal endocervical glands. MUC6 was frequently expressed in normal endocervical glands and endocervical glandular lesions. Endocervical adenocarcinomas sometimes stained only for MUC6. TFF2 is a promising immunohistochemical marker and its identification in uterine cervical secretion is a potentially useful diagnostic test for endocervical glandular lesions with gastric differentiation.

The curious case of Gαs gain-of-function in neoplasia

BACKGROUND

Mutations activating the α subunit of heterotrimeric Gs protein are associated with a number of highly specific pathological molecular phenotypes. One of the best characterized is the McCune Albright syndrome. The disease presents with an increased incidence of neoplasias in specific tissues.

MAIN BODY

A similar repertoire of neoplasms can develop whether mutations occur spontaneously in somatic tissues during fetal development or after birth. Glands are the most "permissive" tissues, recently found to include the entire gastrointestinal tract. High frequency of activating Gαs mutations is associated with precise diagnoses (e.g., IPMN, Pyloric gland adenoma, pituitary toxic adenoma). Typically, most neoplastic lesions, from thyroid to pancreas, remain well differentiated but may be a precursor to aggressive cancer.

CONCLUSIONS

Here we propose the possibility that gain-of-function mutations of Gαs interfere with signals in the microenvironment of permissive tissues and lead to a transversal neoplastic phenotype.

Adenocarcinoma arising in urinary bladder endocervicosis

Endocervicosis is a rare benign condition characterized by the presence of endocervical-type mucinous glands. Urinary bladder endocervicosis forms an elevated lesion in the posterior wall of the urinary bladder and is sometimes misdiagnosed as a malignant tumor clinically and pathologically. Herein we describe the first case of adenocarcinoma arising in urinary bladder endocervicosis. The patient, a 58-year-old woman, presented with asymptomatic hematuria. Cystoscopy revealed a nodular mass measuring 4 cm in diameter in the posterior wall, and total cystectomy was performed. Histology revealed that the elevated lesion of the bladder wall was composed of haphazard proliferation of cystic glands lined by benign endocervical-type epithelium. An adenocarcinoma arose at the center of this endocervicosis. Mucin histochemistry revealed the presence of sulfomucin in both the endocervicosis and adenocarcinoma components. Immunohistochemically, the endocervicosis was positive for cytokeratin (CK) 7, AE1/AE3, CAM5.2, HBME1, CA19-9, and estrogen receptor (ER), and negative for CK20, CDX2, progesterone receptor (PR), MUC5AC, and β-catenin. The adenocarcinoma showed similar immunohistochemical results, except for loss of ER expression and a slight increase in the ratio of Ki-67-positive cells. This case indicates that endocervicosis, known as a benign lesion, harbors the possibility of malignant transformation.

Reappraisal of the Immunophenotype of Pancreatic Intraductal Papillary Mucinous Neoplasms (IPMNs)-Gastric Pyloric and Small Intestinal Immunophenotype Expression in Gastric and Intestinal Type IPMNs-

Pancreatic intraductal papillary mucinous neoplasms (IPMNs) are mucin-producing neoplasms of the main and/or branch pancreatic ducts. To assess differences between various IPMN subtypes, immunohistochemical markers of gastric surface mucous cells (MUC5AC), gastric gland mucous cells (MUC6 and GlcNAcα1→4Galβ→R), gastric pyloric and duodenal epithelial cells (PDX1), intestinal cells (MUC2 and CDX2), small intestinal cells (CPS1) and large intestinal cells (SATB2) were evaluated in 33 surgically treated IPMNs. MUC2 expression classified IPMNs into gastric (n=17), intestinal (n=8) and mixed gastric and intestinal type (collision=7, composite=1). No differences in age or sex were observed among these types. MUC5AC and PDX1 were expressed in all IPMNs. MUC6 expression was higher in gastric and mixed types than in intestinal type. GlcNAcα1→4Galβ→R was detected in gastric and mixed type, but not in intestinal type. MUC2 and CDX2 expression were higher in intestinal type than gastric and mixed type. CPS1 expression was higher in intestinal type than gastric type. SATB2 was not observed in any IPMNs. Frequent abrupt transition between the two IPMN types in mixed-type IPMNs was observed. Gastric pyloric and small intestinal differentiation are characteristic of gastric and intestinal type IPMN, respectively, and these two IPMN types may have distinct pathogenesis.

Claudin-18 overexpression in intestinal-type mucinous borderline tumour of the ovary

AIMS

Mucinous borderline tumours of the ovary are subclassified as intestinal-type (IMBT) and endocervical-like (EMBT), which differ in their clinicopathological features. In this study, we attempted to elucidate characteristics of the mucinous epithelium in each subtype.

METHODS AND RESULTS

The expression of claudin-18, a marker of gastric differentiation, MUCs, CDX2, CK7, CK20, oestrogen receptor (ER), progesterone receptor (PgR), CA-125 and vimentin in IMBTs (n = 54), EMBTs (n = 25) and serous borderline tumours (SBTs) (n = 22) were compared by immunohistochemistry. Claudin-18 positivity was identified in 98% of the IMBTs, whereas only 4% of the EMBTs were claudin-18-positive. Expression of intestinal markers such as CDX2 and MUC2 was relatively infrequent in IMBTs (48% and 33%, respectively). Müllerian-lineage markers such as ER, PgR and vimentin were expressed rarely in IMBTs, while most EMBTs and SBTs were positive for these markers. Hierarchial clustering revealed a close association between EMBTs and SBTs, while IMBTs were clearly separate.

CONCLUSIONS

Claudin-18 positivity is a specific phenotype that is characteristic of IMBTs. Frequent and diffuse expression of gastric markers, along with less frequent and usually focal expression of intestinal markers, suggests that IMBTs are essentially composed of gastrointestinal-type mucinous epithelium (gastric-type epithelium with a variable degree of intestinal differentiation).