Pathology International最新文献

Gastric cancer (GC) confined to the mucosa (pT1a-GC) has a low incidence (approximately 3%) of lymph node metastasis (LNM), making it a suitable candidate for endoscopic resection. However, the current risk stratification system inadequately identifies high-risk patients. Although RhoGAP fusion has been identified as a risk factor for LNM in pT1b-GC, its role in pT1a-GC remains unclear. In the present study, medical records of 1099 surgically resected pT1a-GC cases over 12 years were reviewed, identifying 33 cases (3.0%) with LNM. A case-control study compared these cases to 99 LNM-negative cases based on clinicopathological data. Histological reviews and fluorescence In Situ hybridization assays to evaluate RhoGAP fusions, represented by CLDN18::ARHGAP26, were conducted. Univariate analysis revealed significant associations between LNM and larger tumor size (> 30 mm), mixed histological type, muscularis mucosae invasion (MMI), microtubular-mucocellular histology, and RhoGAP fusion. Multivariate analysis identified RhoGAP fusion and MMI as independent LNM predictors. Among LNM-positive cases, RhoGAP fusion was observed in 51.5% (17/33) and was associated with younger age and less frequent MMI. In conclusion, RhoGAP fusion and MMI may be significant biomarkers for LNM in pT1a-GC. Incorporating these factors could enhance risk stratification and inform clinical management strategies for pT1a-GC.

A gastric neuroendocrine tumor (NET) with pancreatic acinar cell differentiation is extremely rare. We report the case of an 87-year-old woman with a submucosal tumor in the gastric body on a background of atrophic gastritis. She also had Sjögren's syndrome. Initially 17.8 × 6.5 mm, the tumor enlarged over 10 years, leading to wedge resection. The resected mass (45 × 40 × 30 mm) was solid with a pale yellow to gray-white cut surface. Histologically, it showed trabecular or solid nests of epithelial cells with round nuclei and eosinophilic cytoplasm. Immunohistochemistry showed positivity for CKAE1/3, VMAT2, neuroendocrine markers, and pancreatic acinar markers. Ki-67 index was 11.2%. The tumor co-expressed PDX1 and ARX and showed loss of menin and ATRX. These findings support a diagnosis of gastric ECL-cell NET G2 arising in autoimmune gastritis, with secondary pancreatic acinar differentiation. This tumor may represent a variant of type 1 gastric NET.

Complete loss of nuclear SMARCB1 expression was originally described as a hallmark of malignant rhabdoid tumors, typically occurring in the kidney, soft tissue, and central nervous system (CNS). Generally, SMARCB1 deficiency is associated with malignant histopathological appearance, except for some rare tumors. Herein, we present a case of hitherto undescribed SMARCB1-deficient pulmonary mesenchymal tumor without rhabdoid features or malignant histopathology involving a 62-year-old male patient. Histologically, the tumor demonstrated a moderately cellular proliferation of monomorphic spindle cells arranged in short fascicles or a storiform pattern with intervening collagenous stroma. The mitotic activity was lower than that of typical SMARCB1-deficient tumors, and rhabdoid features and necrosis were absent. Nuclear SMARCB1 expression was lost, and a part of SMARCB1 was revealed to be homozygously deleted. DNA methylation analysis demonstrated that this case was not clustered with other well-known SMARCB1-deficient tumors.

The study investigated the clinicopathological features and characteristic immune tumor microenvironment (TME) of lung squamous cell carcinoma (SqCC) adjacent to emphysematous lesions. 184 consecutive patients with peripheral-type SqCC who had undergone complete surgical resection were enrolled. The clinicopathological differences between emphysema-adjacent SqCC (EA-SqCC) and non-emphysema-adjacent SqCC (non-EA-SqCC) were examined. The immune TME, including tumor-infiltrating lymphocytes (TILs) and PD-L1 expression, was also analyzed. EA-SqCC was detected in 132 (71.7%) of the 184 patients. Patients with EA-SqCC had shorter recurrence-free survival (RFS) [median 58.2 months vs. not Reached (NR); hazard ratio (HR) 0.47; 95% CI 0.25-0.81, p < 0.01] and tended to have shorter overall survival (NR vs. NR; HR 0.47; 95% CI 0.27-1.03, p = 0.07) compared to patients with non-EA-SqCC. Evaluation of TILs in the cancer stroma showed the number of Foxp3+ TILs in the EA-SqCC group was significantly higher than that in the non-EA-SqCC group (median number 58 vs. 43, p < 0.01). However, there were no significant differences in the number of CD8 + T cells and the PD-L1 expression between the two groups. Immunosuppressive microenvironment is a characteristic feature of EA-SqCC, which may contribute to the poor prognosis of this disease.

Reactive mesothelial cells (RMCs) are of interest for differentiating mesothelioma from benign conditions and have been discussed in cytology and biopsy; however, their behavior in the body remains poorly understood. In this study, we report an autopsy case of an older woman with a long-standing pleural effusion due to cardiac disease, providing insights into the relationship between body cavities, and lymphatic vessels (LVs), mesothelial cells (MCs), and endothelial cells. Cytological examination of pleural effusion revealed RMCs with mild atypia, multinucleation, and intercellular phagocytosis. Immunohistochemistry confirmed the mesothelial origin of these cells. Autopsy findings showed extensive involvement of RMCs in the pleura, diaphragm, peritoneum, lymph vessels, and lymph node sinuses. The visceral pleural submesothelial LVs were dilated, had small openings in the thoracic cavity, and were lined with endothelial and mesothelial cells. Large cavernous LVs with MC clusters were observed on the diaphragm. These structures resembled "stomata" or "lacunae," suggesting a mechanism by which RMCs migrate from the body cavities to the lymphatic network. This study focuses on the RMCs in LVs and shows the contiguity between body cavities and lymphatic networks, providing important insights into the flow of bodily fluids.

Air transport of FFPE cancer tissue samples led to increased DNA fragmentation, primarily due to radiation exposure rather than temperature changes or freeze-thaw cycles. While overall degradation was minor, critical samples requiring high nucleic acid integrity may benefit from local testing or research. Avoiding air transport could help mitigate potential risks and ensure reliable results.

The incidence of upper tract urothelial carcinoma (UTUC) in Taiwan is high, characterized by aggressive clinical behavior and a tendency to be more invasive at diagnosis. Identifying tumorigenic genes remains an important challenge. Myc binding protein 2 (MYCBP2) regulates the cAMP, p38MAPK, TSC/mTOR, and autophagy signaling pathways in mammalian cells. MYCBP2 dysfunction has been associated with poor prognosis in leukemia, melanoma, colon, and prostate cancer. Its role in UTUC needs to be clarified. We investigated the expression of MYCBP2 in UTUC and its relationship to patient outcomes. MYCBP2 expression levels were assessed by immunohistochemistry in 110 tissue samples from UTUC patients. Higher MYCBP2 protein expression was significantly correlated with worse disease-free survival (p = 0.001) and cancer-specific survival (p = 0.007). The major clinicopathological characteristics associated with MYCBP2 expression were stage, lymphovascular invasion, distant metastasis, recurrence, and cancer death. Based on multivariate analysis, pathological stage (HR:2.31, p = 0.017) and MYCBP2 expression (HR:2.75, p = 0.015) were significant predictors of disease-free survival in UTUC. MYCBP2 is elevated in UTUC cell lines compared with immortalized uroepithelial cells. Knocking down MYCBP2 significantly suppressed cellular migration and invasion activity in BFTC909 cells. In conclusion, MYCBP2 expression might predict poor survival among UTUC patients.

Kidney injury molecule-1 (KIM-1) is a potential prognostic marker of advanced-stage clear cell renal cell carcinoma (ccRCC) and is associated with tumor immunogenicity. Little is known about its role in early-stage ccRCC, especially in pathological T1b (pT1b) disease, which shows a higher recurrence rate than pT1a disease. Resected specimens from 112 pT1b ccRCC cases were reviewed and immunohistochemically analyzed for KIM-1 expression. High membranous KIM-1 expression was defined as H score ≥ 140, based on the immunoreactive intensity and area, and cytoplasmic expression in ≥ 10% of cancer cells was considered as high cytoplasmic KIM-1 expression. KIM-1 expression status was compared with clinicopathological variables, including tumor-associated immune cell (TAIC) status. Among the 112 cases, high membranous and cytoplasmic KIM-1 expression was observed in 30 (27%) and 38 (34%) cases, respectively. High membranous KIM-1 expression was significantly associated with a higher nuclear grade, tumor necrosis, hot TAIC status, and shorter recurrence-free survival (RFS) and cancer-specific survival, whereas high cytoplasmic expression was only related to a higher nuclear grade. Multivariate Cox regression analysis revealed that high membranous KIM-1 expression and tumor necrosis were independent predictors of shorter RFS. Our results indicate that membranous KIM-1 expression could be a biomarker for predicting postnephrectomy recurrence in pT1b ccRCC.