Kazuyuki Ishida

Endometrial cytological findings for a mesonephric‐like endometrial adenocarcinoma: A case report

AbstractA mesonephric‐like endometrial adenocarcinoma (ML‐EAC) is very rare and has a worse prognosis than other endometrial carcinomas. We describe an ML‐EAC and report our endometrial cytological findings. A 76‐year‐old woman presented with irregular genital bleeding and a uterine mass. Endometrial cytology revealed atypical cylindrical or spindle‐shaped cells in the form of small aggregates or solitary cells. The cell aggregates exhibited irregularly stacked papillary structures, small glandular structures, and fenestrated structures. The atypical cells had a nucleus with fine‐granular chromatin and a granular cytoplasm, and nuclear grooves and intranuclear pseudo‐inclusions were present. Hyaline globules were observed in the glandular lumens and in the background. The presumptive histological type was an adenocarcinoma, but the cytological features were different from those of an endometrioid carcinoma. A histological examination of the endometrial biopsy revealed an adenocarcinoma, and a simple hysterectomy was performed. A grayish‐white elevated mass measuring 90 mm × 70 mm × 40 mm was observed on the uterine corpus in the hysterectomy specimen. Histologically, the tumor proliferated as complex tubular structures containing eosinophilic colloid‐like materials and trabecular structures. The tumor cells were diffuse and positive for GATA‐3 and partially positive for thyroid transcription factor‐1. Estrogen and progesterone receptors were negative. An ML‐EAC was diagnosed. The tumor was invasive and extended beyond one‐half of the muscle layer with a high degree of vascular invasion. In conclusion, we need to focus on the various shapes of the cell aggregate, nuclear grooves, and intranuclear pseudo‐inclusions of tumor cells to distinguish an ML‐EAC from other endometrial carcinomas in endometrial cytology.

Impact of immunohistochemistry-based molecular classification with conventional risk stratification on recurrence and survival outcomes in endometrial cancer

The conventional histomorphology-based risk classification for endometrial cancer (EC) does not consider the molecular heterogeneity that influences prognosis and treatment response. The Proactive Molecular Risk Classifier for Endometrial Cancer (ProMisE) system uses next-generation sequencing to assess DNA polymerase epsilon (POLE) mutations, but its high cost limits its accessibility. This study evaluated the prognostic value of a novel algorithm that combined immunohistochemistry (IHC) testing with conventional risk factors. This retrospective study included 237 patients with stage I-III EC who underwent surgery. Low-risk patients were classified without IHC, while intermediate- and high-risk patients were categorized as MMR-deficient (MMRd), p53-abnormal (p53abn), or nonspecific molecular profile (NSMP) groups based on IHC. Additionally, L1CAM expression was also evaluated. Survival outcomes were analyzed using Kaplan-Meier curves and Cox regression models. Data from 233 cases were analyzed; the median follow-up duration was 63 months. Among 87 low-risk patients, only 1 experienced recurrence. The intermediate- and high-risk groups were subdivided into 42 MMRd, 16 p53abn, and 88 NSMP patients. The 5-year disease-free survival (DFS) rates were 98.8% (low-risk), 94.7% (NSMP), 80.6% (MMRd), and 59.8% (p53abn), highlighting the poorer prognosis of p53abn. p53abn independently predicted recurrence (hazard ratio [HR], 10.1) and mortality (HR, 25.6). L1CAM positivity correlated with worse DFS but was not an independent prognostic factor. Conventional risk classification combined with IHC classification using p53 and MMR is a cost-effective prognostic tool that enables risk stratification and personalized treatment decisions, even when genetic testing is unavailable.

A Case Study of a High-Grade Serous Carcinoma of the Fallopian Tube Transformed into Carcinosarcoma at the Site of Peritoneal Dissemination With Immunohistological Evidence of an Epithelial–Mesenchymal Transition

We report a patient in whom a primary high-grade serous carcinoma (HGSC) of the fallopian tube transformed into a carcinosarcoma at the site of peritoneal dissemination, and immunohistological analysis suggested the involvement of an epithelial–mesenchymal transition (EMT). The patient, a 70-year-old woman, had an abdominal mass palpated on admission, and a laparotomy was performed after a close examination. The resected right fallopian tube was cystically dilated, and a solid mass was observed in its lumen. The histological diagnosis was HGSC of the right fallopian tube with a papillary or complex tubular structure composed of tumor cells with marked nuclear irregularities. p53 was overexpressed, and no mesenchymal tumor component was observed. The resected left-sided abdominal mass of the omentum was a solid with a long diameter of 100 mm. Microscopically, the tumor exhibited a mixture of HGSC and high-grade sarcoma with nonspecific differentiation. Furthermore, a heterologous chondrosarcoma was subsequently observed from the high-grade sarcoma. The HGSC component was E-cadherin positive. The high-grade sarcoma component was positive for EMT-related proteins such as zinc finger E-box–binding homeobox 1 (ZEB1) and twist family bHLH transcription factor 1 (TWIST1). The chondrosarcoma component was ZEB1 positive and TWIST1 negative. p53 overexpression was found in all 3 components. The tumor of the omentum suggested that an EMT phenomenon was involved in the tumorigenesis. In this scenario, the primary HGSC of the fallopian tube with obvious invasion demonstrated that the conversion from carcinoma to sarcoma by EMT occurs only with peritoneal dissemination.