Background and purpose: Collecting duct carcinomas of the kidney are a rare malignant tumor accounting for<1%of renal malignancies. It is associated with aggressive nature and more than 50%of patients have metastatic disease at the time of initial diagnosis. The diagnosis of collecting duct carcinoma is often dififcult and to some extent is one of exclusion. This study aimed to study the clinicopathologic features of collecting duct carcinoma of the kidney. Methods:We retrieved the data of ifve cases of collecting duct carcinomas of the kidney from pathology ifles, and determined the expressions of CK19, CAM5.2, CK7, Vimentin, CD10, P63 and PaX-8 by pathohistological observation and immunohistochemical examination. Results: The most common symptoms were blood urine, bellyache and abdomen mass. The tumor originated from the medulla of the kidney central zone. Histologically, the tumors demonstrated irregular tubular or papillary architecture with the stroma of inflammatory cells and fibrous tissue proliferation. Immunohistochemically, the tumor cells were positive for CK19(5/5), CAM5.2(5/5), PaX-8(5/5), Vimentin(2/5), CK7(1/5), and negative for P63, CD10. Conclusion: The correct diagnosis in collecting duct carcinomas of the kidney is based on characteristic morphological features and immunophenotype labeling.

Background and purpose: Solid papillary carcinoma (SPC) is an uncommon histological pattern accounting for <1% of breast carcinomas. It is a distinctive form of papillary carcinoma characterized by closely apposed expansile, cellar nodules. The present study aimed to investigate the clinicopathologic features, immunophenotype and prognosis of SPC of breast. Methods:We retrieved the data of 32 cases of SPC of the breast from pathology files, and determined the expressions of ER, PR, C-erbB-2, p63, Calponin, CK5/6, Ki-67, Syn and CgA by pathohistological observation and immunohistochemical examination. Results:All the patients were females with a mean age of 67.3 years. The clinical features were a palpable mass or bloody nipple discharge. The tumor was observed as a whitish-grey or yellowish-brown, lfeshy ifrm or soft, nodular circumscribed mass on gross examination. Microscopy showed solid and papillary area inside the capsule wall and that fine delicate fibrovascular septa were discovered amid the solid proliferation. The tumor cells were oval, polygonal, spindled or signet ring-like with abundant eosinophilic cytoplasm and contained mildly to moderately pleomorphic nuclei. Immunohistochemically, all tumor cells were strongly positive for ER and PR (++-+++), negative for C-erbB-2 and all cases were negative for CK5/6, p63 and Calponin in the cellular nodules. The positive expression rates of Syn and CgA were 68.8%and 78.2%, respectively. The average positive rate of Ki-67 in tumor cells was 7.5%(2%-20%). Twenty-seven patients were available for follow-up examination from 6 to 84 months and 25 patients were alive and disease free. One patient had tumor recurrence, and was alive after reoperation. Another patient died of the tumor metastasis. Conclusion:SPC is predominantly found in elderly females with distinctive pathological features and immunophenotype. SPC often carries an indolent clinical behavior, and even if accompanied by inifltration, very rare cases have recurrence and metastasis after resection, so its prognosis is better.

Objective To investigate the clinicopathological features and prognoses of papillary glioneuronal tumor (PGNT), and to improve the understanding of clinical worker on the tumor. Methods Three patients with PGNT got conformation in our center from July 1, 2011 to Apral 20, 2019, were chosen. The clinical features, histopathological characteristics, immunohistochemical findings, and prognoses of these patients were retrospectively analyzed. Results Two patients were female and one was male. Two tumors were located in the lateral ventricle and one in the temporal lobe. All patients presented with headache, and two exhibited dizziness. Imaging showed solid or cystic mass with well-defined boundary. Microscopically, it was characterized by papillary structures covered by single to multiple layers of small cuboidal gliocytes, and neurocyte-like cells scattered between the papilla. Immunohistochemically, the tumor cells covering papilla were positive for glial fibrillary acidic protein and oligodendrocyte transcription factor 2, and neurocyte-like cells were positive for synaptophysin; and the tumor cells were negative for isocitrate dehydrogenase 1 and silk/threonine specific protein kinase gene BRAF V600E. The proliferating cell nuclear antigen Ki-67 labeling index ranged from 1％-2％. Three patients were followed up for 12, 24 and 48 months after tumor resection, respectively, and no recurrence was found. Conclusion PGNT is an uncommon and variant of mixed neuronal-glial neoplasm with low-grade malignancy; the prognosis is good after gross total resection.

DNA methylation is an epigenetic modification form with the most extensive and in-depth studying. DNA methylation is a powerful tool for tumor classification in the central nervous system (CNS), which is used in the molecular classification of various tumors, such as ependyma and meningioma, to accurately predict tumor biological behavior and survival prognosis, and to provide important information for individualized treatment. DNA methylation will also become an important auxiliary diagnostic method for the identification of different types of CNS tumors, improve the accuracy of pathological diagnosis, and even help to find new tumor entities. In the current review, we focus on the role of DNA methylation in the molecular classification and pathological diagnosis of CNS tumors, in order to provide more enlightenment for accurate diagnoses and treatments of tumors.