We aimed to analyze the clinicopathological features and outcomes of patients with gastric-type of HPV-independent endocervical adenocarcinoma (GAS HPVI ECA), and compare them with non-GAS HPVI ECA cases. Thirty-eight GASs [including 17 minimal deviation adenocarcinoma (MDA), 21 non-MDA GAS] and 17 non-GAS HPVI ECAs were studied. Data of clinical features, pathological characteristics, treatment, and outcomes were evaluated. The median age of patients with GAS and non-GAS HPVI ECA was 46 and 48 years, respectively (p = 0.93). Compared with non-GAS HPVI ECAs, GAS had more common complains of vaginal watery discharge (p = 0.04). GAS cases were also associated with higher clinical stage (p = 0.036), more common in deeper cervical stromal invasion (p = 0.002) and lymphoavascular invasion (p = 0.044). GAS was associated with worse median progression-free survival (PFS) (p = 0.02) and median overall survival (OS) (p = 0.03) over patients with non-GAS HPVI ECAs. MDA had similar clinical and pathological features and prognosis compared with non-MDA GAS. Of note, serum CA19–9 levels were significantly higher in GAS than that in non-GAS HPVI ECA cases. GAS cases were more likely to have high risk pathological factors and poorer PFS and OS compared with non-GAS HPVI ECAs. Serum CA19–9 may be helpful for diagnosis and screening in patients with GAS.

Pilomatrix-like high-grade endometrial carcinoma (PiMHEC) is a rare and aggressive variant of endometrial carcinoma often misdiagnosed due to overlapping features with other high-grade malignancies. This study characterizes its clinicopathologic, immunophenotypic, and molecular features to establish key diagnostic criteria and propose a standardized terminology. Ten tumors were analyzed using histopathologic examination, immunohistochemistry, and next-generation sequencing. All but 1 tumor exhibited both low-grade endometrioid and high-grade basaloid components, the latter characterized by either geographic or comedo-type necrosis and shadow cells. Although shadow cells are a hallmark feature, they may be focal or absent, necessitating careful evaluation. High-grade areas consistently showed ER and PR negativity with diffuse nuclear β-catenin staining, correlating with CTNNB1 exon 3 mutations in all tumors. Identical CTNNB1 mutations in spatially distinct tumor components suggest a clonal progression from a low-grade precursor. Additional mutations in ARID1A, PTEN, and PIK3CA were identified. Clinically, PiMHEC exhibited aggressive behavior, with 7 patients experiencing recurrence and 1 succumbing to the disease within 9 months. Metastatic sites included the lungs, liver, lymph nodes, and abdominal wall. PD-L1 expression in 4 tumors suggests potential responsiveness to immune checkpoint inhibitors, whereas low-level HER2 expression (1+ to 2+) in 5 tumors raises the possibility of HER2-targeted therapies. Folate receptor alpha was not expressed in any tumor. In conclusion, PiMHEC is a distinct and highly aggressive endometrial carcinoma with unique histopathologic and molecular features that differentiate it from high-grade endometrioid and other high-grade endometrial cancers including squamous cell carcinoma in rare situations. Its key diagnostic features include high-grade basaloid tumor cells associated with shadow cells, tumor necrosis, and diffuse nuclear β-catenin staining. To improve diagnostic accuracy and reduce ambiguity, we propose adopting “pilomatrix-like high-grade endometrial carcinoma” as a standardized term.

Despite the well-established pathogenic effect of high-risk human papillomavirus (hrHPV) genotypes on endocervical adenocarcinomas (ECAs), the prognostic values of hrHPV genotypes and their association with other prognostic variables have not been established. We categorized 120 usual-type human papillomavirus–associated (HPVA) ECA cases into 3 species groups (HPV16+, HPV18/45+, and other genotypes+) based on the hrHPV status. The clinical-stage, invasion patterns (Silva), and programmed death ligand-1 (PD-L1) expression were compared among genotype groups. In addition, log-rank test and Kaplan-Meier survival curves were used to compare progression-free survival (PFS) among different patient groups. A total of 120 ECA cases with positive hrHPV tests were included in this study. Among them, 51 (42.5%) were positive for HPV16, 50 (41.7%) were positive for HPV18 or 18/45, 9 (7.5%) were positive for other hrHPV genotypes (not including HPV16/18/45). Our data showed patients had no significant difference in clinical stages (P=0.51), invasion patterns (P=0.55), and PFS (P=0.59) across genotype groups. Overall, a relatively high prevalence of PD-L1 expression was observed in HPVA ECAs (25% by tumor proportion score [TPS] and 55% by a combined positive score [CPS]). Using TPS, 19.6% (10/51) HPV16+ cases, 32.0% (16/50) cases of HPV18 or 18/45+ cases, and 22.2% (2/9) cases of other genotypes+ cases demonstrated PD-L1 positivity. No significant difference in PD-L1 expression was seen across genotype groups (P=0.35). PD-L1 expression in tumors with patterns B and C was significantly higher than in those with pattern A (P=0.00002). Patients with PD-L1-positive tumors by either CPS or TPS showed significantly poorer PFS than those with PD-L1-negative tumors (CPS, P=0.025; TPS, P=0.001). Our data support that HPV genotypes have no prognostic value in HPVA ECAs, while PD-L1 expression serves as a negative prognostic marker in HPVA ECAs and implies an unfavorable outcome.

Gastric‐type endocervical adenocarcinoma (GEA) is the second most common subtype of endocervical adenocarcinoma and has a poor prognosis. Anti‐programmed death‐1 and anti‐programmed death‐ligand 1 (PD‐L1) inhibitors have emerged as a major treatment option for GEA; however, data on the expression of other immune checkpoints in GEA are limited. We analyzed the expression of T‐cell immunoglobulin and mucin‐domain containing‐3 (TIM‐3) and B7 homolog 3 protein (B7‐H3) in 58 GEA and investigated their prognostic significance as well as association with PD‐L1 expression and other known prognostic factors. Applying the tumor proportion score (TPS) with a cutoff of 1%, B7‐H3 and TIM‐3 were present in 48.3% and 17.2% of cases, respectively. Applying the combined positive score (CPS) with a cutoff of 1, TIM‐3 expression was present in 70.7% of cases. Moreover, the expression of three checkpoints (B7‐H3, TIM‐3, and PD‐L1) was incompletely overlapping. Patients with B7‐H3 positive tumors (by TPS) or TIM‐3 positive tumors (by TPS) had significantly worse recurrence‐free survival (RFS) and overall survival (OS) (log‐rank). Using CPS, patients with TIM‐3 positive tumors showed significantly worse RFS (log‐rank). Similarly, B7‐H3 positivity (by TPS) and TIM‐3 positivity (by TPS) were associated with worse RFS and OS in univariate analysis. TIM‐3 positivity (by CPS) was associated with worse RFS in univariate analysis and the final Cox multivariate analysis. In conclusion, our results show that (1) B7‐H3 and TIM‐3 are frequently expressed in GEA and their expression overlaps incompletely with PD‐L1; and (2) both B7‐H3 and TIM‐3 are independent negative prognostic markers in GEA.