Disseminated peritoneal leiomyomatosis (DPL), also known as leiomyomatosis peritonealis disseminata, is a rare disease characterized by multiple benign smooth muscle tumors proliferating along the peritoneal surfaces. The cause of the disease is unclear, and possible factors include iatrogenic and hormonal stimulation. The patient was a 41-year-old Chinese woman with a history of laparoscopic myomectomy and subsequent pregnancy. Multiple abdominal masses were identified and required surgical intervention. The patient had no tenderness or other discomfort. The clinical and imaging diagnosis was gastrointestinal stromal tumor, but DPL was confirmed by postoperative pathological examination. The patient had a good prognosis, and no recurrence was observed during follow-up. Iatrogenic and hormonal stimulation leading to DPL is very rare, and we believe that multiple factors led to DPL in this case. Clinicians should be aware of such potential patients.

Objectives: The objective of the study was to compare the consistency of various staining methods, including H&E, Methylene Blue, Warthin-Starry (W-S), Immunohistochemistry (IHC) and Quantum dots immunohistochemistry (QDs-IHC), in detecting Helicobacter pylori (HP) in cases of mild, moderate and severe chronic gastritis.Methods: Biopsy samples were obtained from 225 patients with chronic gastritis at the Department of Pathology, Yichang Central People’s Hospital between January 2019 and October 2019. The presence of HP was detected using H&E, Methylene Blue, W-S, IHC, and QDs-IHC.Results: The positive rates for HP detection using H&E, Methylene Blue, W-S, IHC, and QDs-IHC were 42.22%, 51.11%, 53.78%, 59.11%, and 58.67%, respectively. In cases of mild chronic gastritis, the consistency of test results between H&E, Methylene Blue, W-S, and QDs-IHC with IHC were Kappa=0.196, P=0.033, Kappa=0.706, P<0.001, Kappa=0.717, P<0.001, and Kappa=0.968, P<0.001, respectively. Similarly, in cases of moderate chronic gastritis, Kappa values between H&E, Methylene Blue, W-S, and QDs-IHC with IHC were 0.356, P<0.001, 0.655, P<0.001, 0.741, P<0.001, and 0.946, P<0.001, respectively. For cases of severe chronic gastritis, the Kappa values between the staining methods and IHC were 0.271, P=0.037, 0.421, P=0.002, 0.621, P<0.001, and 1, P< 0.001, respectively.Conclusion: The study showed that the positivity rate of IHC was significantly higher than that of H&E, Methylene Blue, and W-S in detecting HP infection in chronic gastritis cases. In terms of consistency with IHC, QDs-IHC was the most reliable staining method across all severity grades, while the agreement between H&E and IHC was poor, and that between Methylene Blue and W-S with IHC was average. Pathology departments may choose the most appropriate staining method based on their specific needs, considering the staining time, contrast, and cost of each method.

Background: Meningioma is a common type of intracranial tumor in adults. It rarely arises in the chest, with only a few case reports in the English literature. Here, we report the case of a patient with a primary ectopic meningioma (PEM) located in the thoracic cavity.Case presentation: A 55-year-old woman presented with exercise-induced asthma, chest tightness, intermittent dry cough and fatigue for several months. Computed tomography revealed the presence of a huge mass in the thoracic cavity, with no connection to the spinal canal. Lung cancer and mesothelioma were suspected, and surgery was performed. Grossly, the mass was a grayish-white solid 9.5 cm × 8.4 cm × 5.3 cm in size. The microscopic morphology of the lesion was consistent with that of typical central nervous system meningioma. The pathological subtype was transitional meningioma. The tumor cells were arranged in a fascicular, whorled, storiform and meningithelial pattern, with occasional intranuclear pseudo-inclusions and psammoma bodies. In focal areas tumor cells were considerably dense, and the cells were round or irregular in shape, with less cytoplasm, uniform nuclear chromatin, and visible nucleoli and mitoses (2/10 HPF). By immunohistochemistry, the neoplastic cells showed strong and diffuse staining with vimentin, epithelial membrane antigen and SSTR2 with variable expression of PR, ALK and S100 protein. However, the cells were negative for GFAP, SOX-10, inhibin, CD34, STAT6, smooth muscle actin, desmin, CKpan, D2-40, WT-1, CK5/6 and CD45. The highest proliferation index by Ki-67 was 15%. The abnormal expression of ALK led to the initial misdiagnosis of an inflammatory myofibroblastic tumor. After 12 months of follow-up, no disease progression was observed.Conclusion: The presence of primary ectopic meningiomas in the thoracic cavity is extremely rare, and this tumor is easily misdiagnosed clinically. Imaging is suggested to determine the location and possible differential diagnosis, while the final diagnosis should be via pathological examination. Immunohistochemistry is crucial for disease diagnosis. Owing to our limited knowledge of PEM, its pathogenesis and tissue of origin remain unclear. Clinicians should pay close attention to such potential patients. The present case report may provide insights into the diagnosis and therapy of patients with this tumor.

This study seeks to address the challenge of melanoma identification in immunohistochemical (IHC) diagnosis, which is complicated by the similar coloration of melanin and DAB (Diaminobenzidine) staining, by introducing methylene blue counterstaining as an innovative solution. We compared the effectiveness of methylene blue counterstaining with that of the traditional hydrogen peroxide bleaching method in the diagnosis of melanoma. The study included 46 paraffin-embedded melanoma samples, and the staining efficacy for markers such as Melan A, HMB-45, PRAME, and Ki-67 was assessed via both methods. The results demonstrated that methylene blue counterstaining effectively converted the brownish-yellow melanin granules to a deep green color, significantly enhancing contrast and clarity with DAB staining. The average contrast and clarity scores for the methylene blue counterstaining method were 1.96 ± 0.21 and 1.91 ± 0.28, respectively, which were significantly greater than those of the conventional IHC group and the hydrogen peroxide bleaching group (P < 0.01). Furthermore, methylene blue counterstaining did not cause noticeable tissue damage or cellular morphology distortion, with tissue integrity scores comparable to those of the conventional IHC group (P > 0.05). Although the contrast and clarity also improved in the hydrogen peroxide bleaching group, it resulted in a significant decrease in tissue integrity (P < 0.01). This study is the first to apply methylene blue counterstaining in melanoma IHC analysis, demonstrating its advantages in enhancing staining quality, simplifying procedural workflows, and preserving antigenicity. This method provides a novel and effective tool for the pathological diagnosis of melanoma, potentially improving diagnostic accuracy and reliability.