Objective: To investigate the clinicopathological characteristics of malignant gastrointestinal neuroectodermal tumors (GNET), and to describe their clinical, histological, immunophenotypic, ultrastructural, and molecular features, diagnosis and differential diagnosis. Methods: Three cases of malignant GNET were collected at Xijing Hospital of the Fourth Military Medical University, from 2013 to 2022. All patients underwent surgical resection of the tumor. Histological, immunohistochemical (IHC), ultrastructural and molecular genetic analyses were performed, and the patients were followed up for six months, three years and five years. Results: There were two males and one female patients. The tumors were located in the ileum, descending colon, and rectum, respectively. Grossly, the tumors were solid, firm, and poorly circumscribed, measured in size from 2 to 4 cm in greatest dimension, and had a greyish-white cut surface. These tumors were histologically characterized by a sheet-like or nested population of oval to spindled cells or epithelioid cells with weakly eosinophilic or clear cytoplasm, small nucleoli and scattered mitoses. Electron microscopy showed neuroendocrine differentiation, and no evidence of melanogenesis. IHC staining showed that the tumor cells were diffusely positive for S-100 protein, SOX10, CD56, synaptophysin and vimentin. They were negative for melanocytic markers, HMB45 and Melan A. All three cases showed split EWSR1 signals consistent with a chromosomal translocation involving EWSR1. Next-generation sequencing in one case confirmed the presence of EWSR1-ATF1 fusion. These patients were followed up for 6 months, 3 years and 5 years, respectively, and all of them developed possible lung or liver metastases, and one of them died of multiple pulmonary metastases. Conclusion: Malignant GNET has distinctive morphological, IHC, and molecular genetic features and it should be differentiated from other malignancies of the gastrointestinal tract, especially clear cell sarcoma and melanoma.
Male ; Humans ; Female ; Biomarkers, Tumor/analysis* ; Gastrointestinal Neoplasms/pathology* ; S100 Proteins/analysis* ; Melanoma

Humans ; Immunoglobulin G ; Lymphadenopathy ; Diagnosis, Differential

Humans ; Carcinoma, Renal Cell/pathology* ; Kidney Neoplasms/pathology* ; Biomarkers, Tumor

Humans ; Sarcoma ; NFATC Transcription Factors ; RNA-Binding Protein EWS

Male ; Humans ; Spermatic Cord ; Mesothelioma ; Mesothelioma, Malignant

Objective: To investigate the clinicopathological characteristics of plurihormonal PIT1-lineage pituitary neuroendocrine tumors. Methods: Forty-eight plurihormonal PIT1-lineage tumors were collected between January 2018 and April 2022 from the pathological database of Sanbo Brain Hospital, Capital Medical University. The related clinical and imaging data were retrieved. H&E, immunohistochemical and special stains were performed. Results: Out of the 48 plurihormonal PIT1-lineage tumors included, 13 cases were mature PIT1-lineage tumors and 35 cases were immature PIT1-lineage tumors. There were some obvious clinicopathological differences between the two groups. Clinically, the mature plurihormonal PIT1-lineage tumor mostly had endocrine symptoms due to increased hormone production, while a small number of immature PIT1-lineage tumors had endocrine symptoms accompanied by low-level increased serum pituitary hormone; patients with the immature PIT1-lineage tumors were younger than the mature PIT1-lineage tumors; the immature PIT1-lineage tumors were larger in size and more likely invasive in imaging. Histopathologically, the mature PIT1-lineage tumors were composed of large eosinophilic cells with high proportion of growth hormone expression, while the immature PIT1-lineage tumors consisted of chromophobe cells with a relatively higher expression of prolactin; the mature PIT1-lineage tumors had consistently diffuse cytoplasmic positive staining for keratin, while the immature PIT1-lineage tumors had various expression for keratin; the immature PIT1-lineage tumors showed more mitotic figures and higher Ki-67 proliferation index; in addition, 25.0% (12/48) of PIT1-positive plurihormonal tumors showed abnormal positive staining for gonadotropin hormones. There was no significant difference in the progression-free survival between the two groups (P=0.648) by Kaplan-Meier analysis. Conclusions: Plurihormonal PIT1-lineage tumor belongs to a rare type of PIT1-lineage pituitary neuroendocrine tumors, most of which are of immature lineage. Clinically increased symptoms owing to pituitary hormone secretion, histopathologically increased number of eosinophilic tumor cells with high proportion of growth hormone expression, diffusely cytoplasmic keratin staining and low proliferative activity can help differentiate the mature plurihormonal PIT1-lineage tumors from the immature PIT1-lineage tumors. The immature PIT1-lineage tumors have more complicated clinicopathological characteristics.
Humans ; Neuroendocrine Tumors ; Pituitary Neoplasms/pathology* ; Pituitary Hormones ; Growth Hormone/metabolism* ; Keratins

Animals ; Mice ; Colon ; Histological Techniques

Objective: To investigate the clinicopathological features of perivascular epithelioid cell tumor (PEComa) of the lung. Methods: Eight PEComa cases of the lung diagnosed at the First Affiliated Hospital of Soochow University, Suzhou, China from July 2008 to December 2021 were collected and subject to immunohistochemical staining, fluorescence in situ hybridization and next generation sequencing. The relevant literature was reviewed and the clinicopathological features were analyzed. Results: There were 5 males and 3 females, aged from 18 to 70 years (mean 39 years). There were 3 cases of the right upper lung, 3 cases of the left lower lung, 1 case of the left upper lung and 1 case of the right middle lung. Seven cases were solitary and 1 case was multifocal (4 lesions). Seven cases were benign while one was malignant. The tumors were all located in the peripheral part of the lung, with a maximum diameter of 0.2-4.0 cm. Grossly, they were oval and well circumscribed. Microscopically, the tumor cells were oval, short spindle-shaped, arranged in solid nests, acinar or hemangiopericytoma-like patterns, with clear or eosinophilic cytoplasm. The stroma was rich in blood vessels with hyalinization. Coagulated necrosis and high-grade nuclei were seen in the malignant case, and calcification was seen in 2 cases. Immunohistochemically, the tumor cells were positive for Melan A (8/8), HMB45 (7/8), CD34 (6/8), TFE3 (4/7), and SMA (3/8). All cases were negative for CKpan and S-100. TFE3 (Xp11.2) gene fusion was examined using the TFE3 break-apart fluorescence in situ hybridization in 5 cases, in which only the malignant case was positive. The next generation sequencing revealed the SFPQ-TFE3 [t(X;1)(p11.2;p34)] fusion. Follow-up of the patients ranged from 12 to 173 months while one patient was lost to the follow-up. The malignant case had tumor metastasis to the brain 4 years after the operation and then received radiotherapy. Other 6 cases had no recurrence and metastasis, and all the 7 patients survived. Conclusions: Most of the PEComas of the lung are benign. When there are malignant morphological features such as necrosis, high-grade nuclei or SFPQ-TFE3 gene fusion, close follow-up seems necessary.
Male ; Female ; Humans ; In Situ Hybridization, Fluorescence ; Perivascular Epithelioid Cell Neoplasms/pathology* ; Lung/pathology* ; Basic Helix-Loop-Helix Leucine Zipper Transcription Factors/genetics* ; Necrosis ; Biomarkers, Tumor/analysis*

Humans ; Glomerulonephritis, Membranoproliferative/pathology* ; Fibronectins

Objective: To identify BRAF V600E mutations in adult Wilms tumor (WT) with overlapping histologic features of metanephric adenoma (MA) and to investigate the clinicopathological features of adult WT. Methods: The clinical features of adult WT diagnosed at the Fudan University Shanghai Cancer Center, Shanghai, China from 2012 to 2021 were reviewed. HE-stained slides of all cases were reviewed by 2 expert pathologists. Representative tissues were selected for BRAF V600E immunohistochemical (IHC) staining and gene sequencing. Results: In adult WT with MA-like areas (cohort Ⅰ, n=6), 5 of the 6 cases were composed of epithelial-predominant and were positive for WT-1 and CD56, respectively, and all were positive for CD57. All 6 cases revealed highly variable Ki-67 indices, ranging from 1% in some areas to 60% in others. 5 of the 6 cases harbored a BRAF V600E mutation. All cases in cohort I were followed up for 23 to 71 months, and all survived. In classical adult WT without MA-like areas cohort (cohort Ⅱ, n=13), all 7 cases with available material were negative for BRAF by IHC and none of them had any BRAF mutation. Conclusions: BRAF V600E mutations are frequently present in adult WT with overlapping morphologically features of MA, but not in those without. More importantly, adult WTs with overlapping histologic features of MA may be an intermediate entity between typical MA and WT that may have a favorable prognosis and possible therapeutic targets.
Adult ; Humans ; Proto-Oncogene Proteins B-raf/genetics* ; China ; Wilms Tumor/genetics* ; Kidney Neoplasms/pathology* ; Mutation ; Adenoma/genetics* ; Biomarkers, Tumor/genetics*