Objective:To investigate the clinicopathological characteristics, immunophenotype and differential diagnosis of atypical forms of microglandular hyperplasia of the cervix (AMGH).Methods:A total of 29 cases of AMGH diagnosed at the Obstetrics and Gynecology Hospital of Fudan University, Shanghai, China from January 2010 to December 2024 were analyzed. Relevant clinical and pathological data of the patients were collected using the electronic medical record system and medical records copied from the outside hospitals. The patients were followed up.Results:Among the 29 cases, 28 were consultation cases, 22 (79%) of the 28 cases were considered as glandular neoplastic lesions by the original institutions. The nature of the lesion was uncertain in 1 case, the diagnosis was suspicious for AMGH in another 1 case, and only 4 cases were clearly diagnosed as AMGH. The median age of the 29 patients was 44 (43, 48) years. Eighteen (62%) of the 29 cases presented as cervical polyp. Twelve of the 16 tested cases were negative for human papillomavirus. The pathological presentation was complex and diverse, including solid, trabecular, cribriform, and papillary patterns, forming pseudo-invasive structures. The glandular epithelium and proliferating reserve cells had diverse morphologies, which presented with abundant eosinophilic cytoplasm or clear cytoplasm. Signet-ring or hobnail cells were also seen. The nuclear atypia was mild, with 0-7 mitotic figures per 10 HPF. Immature squamous metaplasia was noted. The stroma showed edema, myxoid change and hyaline degeneration, accompanied by infiltration of acute and chronic inflammatory cells. Immunohistochemistry demonstrated that p16 was negative in 8/16 of the cases or patchy positive in the other 8/16, Ki-67 positive rate was less than 10% in all 16 cases, p53 was wild phenotype (9/9), and carcinoembryonic antigen was negative in 4/5 cases and focally positive in 1/5 cases, while p63 was positive in 6/9 of the tested cases.Conclusions:AMGH is a benign non-neoplastic lesion of the cervical glands. Half of the cases occur in perimenopausal or postmenopausal women, often presenting as polypoid hyperplasia or localized cervical thickening/elevation with a friable, fragile texture. Microscopically, it may show a pseudoinvasive pattern, making it prone to misdiagnosis as a malignant lesion. Thus, differentiation from cervical adenocarcinoma, clear cell carcinoma and microglandular endometrioid carcinoma is required. Integration of clinical history, immunohistochemistry and molecular testing may aid in the differential diagnosis.

Objective:To investigate the clinicopathological characteristics of ossifying fibromyxoid tumor (OFMT) with rare fusion subtypes.Methods:Three cases of OFMT with rare fusion subtypes, diagnosed and consulted in the Zhejiang Hospital, Zhejiang Provincial People′s Hospital, Hangzhou, China and Ningbo Clinical Pathology Diagnosis Center, Ningbo, China from January 2016 to December 2024 were collected. Immunohistochemistry (IHC), fluorescence in situ hybridization (FISH), and targeted RNA sequencing were performed to analyze the immunohistochemical and molecular genetic characteristics of these OFMT. Literature review was also conducted.Results:All three patients were male, with ages of 50, 74, and 58 years, respectively. The tumors were located in the left foot, left thigh, and left lumbar region, respectively, and all presented as slowly growing, painless masses in the skin or subcutaneous tissue. Grossly, the tumors measured 3.5 cm, 6.3 cm, and 5.0 cm in maximum diameter, respectively, with a grayish-white to grayish-yellow, solid, lobulated cut surface. One case exhibited a noticeable myxoid texture. Microscopically, one tumor was located in the superficial dermis, while the other two were in the subcutaneous tissue. The tumors were well-demarcated and showed a lobulated or multinodular growth pattern. None of the cases had a complete surrounding bony shell (only one case had very focal ossification). The tumor cells were monomorphic, short spindle-shaped, oval to epithelioid, and arranged in solid sheets, trabeculae, and small nests within a variably fibromyxoid stroma. Case 1 exhibited abundant pseudorosette-like structures formed by short spindle cells surrounding acellular fibrous stroma. Case 2 showed focal transition of epithelioid tumor cells into fasciculately arranged spindle cells, with extensive stromal hyalinization. Case 3 had a predominantly myxoid stroma with a rich network of thin-walled blood vessels. The tumor cells exhibited mild nuclear atypia with 1-3 mitotic figures per 50 high-power fields. All three cases showed diffuse and strong expression of CD10. Two of the three cases showed nuclear expression of TFE3, while one case showed diffuse and strong expression of desmin and S-100. Targeted RNA sequencing revealed PHF1 (ex12)::TFE3 (ex7) fusion in two cases and MEAF6 (ex5)::PHF1 (5′UTR) fusion in one case, which were further confirmed by FISH study. All three patients underwent tumor resection. Two showed no recurrence during follow-up periods of 98 months and 15 months, respectively, while one experienced local recurrence at 12 months postoperatively.Conclusions:OFMT with rare fusion subtypes often exhibits atypical histological and immunophenotypic features, and lacks a characteristic bony shell. Incorporating TFE3 into the diagnostic IHC panel greatly aids in screening for the cases with rare PHF1::TFE3 fusions. Familiarity with the histological and immunophenotypic characteristics, and differential diagnostic points of these rare OFMT subtypes, is essential for judicious use of molecular genetic tools in achieving a definitive diagnosis.

Objective:To investigate the clinical values of fluorescent PCR-capillary electrophoresis (PCR/CE) for detecting somatic mutations in the proofreading exonuclease domain of DNA polymerase epsilon (POLE-exo*) in endometrial carcinomas (EC), as compared with Sanger sequencing.Methods:A total of 280 EC cases diagnosed at the Department of Pathology at Peking University Third Hospital, Beijing, China from December 2022 to December 2023 were collected. Ten cases, which had previously been confirmed to harbor POLE pathogenic mutations through next-generation sequencing (NGS), were excluded. Subsequently, parallel sequencing using both PCR/CE and Sanger sequencing methods was conducted on the remaining 270 EC samples without prior POLE testing, aiming to examine 11 known pathogenic mutation-sites located within exons 9, 11, 13, and 14 of the POLE gene. NGS was then carried out on the EC cases in which the PCR/CE and/or Sanger sequencing results indicated the presence of POLE-exo*.Results:Among the 270 EC samples, POLE-exo* was detected in 4 cases (4/270, 1.5%) using Sanger sequencing. In contrast, the PCR/CE identified POLE-exo* in 12 cases (12/270, 4.4%). It was noteworthy that all cases in which POLE-exo* was detected through Sanger sequencing were also successfully identified using PCR/CE (4/4, with a detection rate of 100%). These results were further verified by NGS. The PCR/CE also uncovered an additional 8 cases (8/266, 3.0%) of POLE-exo* in the 266 samples that were negative for POLE mutations per Sanger sequencing. Of these 8 cases, 4 were validated using NGS, exhibiting variant allele frequency (VAF) below 10%, but tumor mutation burdens exceeding 10 mutations per megabase. However, due to small tumor sizes, NGS verification could not be performed on the remaining 4 PCR/CE-positive but Sanger-negative cases.Conclusion:The PCR/CE exhibits better sensitivity and detection capabilities than the Sanger sequencing in identifying POLE-exo* in EC samples, particularly in detecting low VAF.

Humans ; Class I Phosphatidylinositol 3-Kinases/genetics* ; Breast Neoplasms/diagnosis* ; Mutation ; Female ; China ; DNA Mutational Analysis/methods* ; Genetic Testing/standards*

Humans ; Colorectal Neoplasms/pathology* ; Pathology, Molecular/methods* ; Biomarkers, Tumor/genetics* ; Genetic Testing ; China

Humans ; Glioma/metabolism* ; Consensus ; China ; Brain Neoplasms/pathology* ; Pathology, Molecular

Humans ; Ovarian Neoplasms/metabolism* ; Female ; Biomarkers, Tumor/metabolism* ; Mutation

Humans ; Consensus ; High-Throughput Nucleotide Sequencing/standards* ; Neoplasms/diagnosis* ; Quality Control ; Sequence Analysis, DNA/methods* ; Sequence Analysis, RNA/methods*

Humans ; Thyroid Neoplasms/metabolism* ; Consensus ; Thyroidectomy ; China ; Immunohistochemistry ; Postoperative Period

Humans ; Biomarkers, Tumor/metabolism* ; Claudins/analysis* ; Consensus ; Immunohistochemistry/methods* ; Stomach Neoplasms/diagnosis*