Objective:To investigate the pathological characteristics and the clinical significance of novel coronavirus (2019-nCoV)-infected pneumonia (termed by WHO as coronavirus disease 2019, COVID-19).Methods:Minimally invasive autopsies from lung, heart, kidney, spleen, bone marrow, liver, pancreas, stomach, intestine, thyroid and skin were performed on three patients died of novel coronavirus pneumonia in Chongqing, China. Hematoxylin and eosin staining (HE), transmission electron microcopy, and histochemical staining were performed to investigate the pathological changes of indicated organs or tissues. Immunohistochemical staining was conducted to evaluate the infiltration of immune cells as well as the expression of 2019-nCoV proteins. Real time PCR was carried out to detect the RNA of 2019-nCoV.Results:Various damages were observed in the alveolar structure, with minor serous exudation and fibrin exudation. Hyaline membrane formation was observed in some alveoli. The infiltrated immune cells in alveoli were majorly macrophages and monocytes. Moderate multinucleated giant cells, minimal lymphocytes, eosinophils and neutrophils were also observed. Most of infiltrated lymphocytes were CD4-positive T cells. Significant proliferation of type Ⅱ alveolar epithelia and focal desquamation of alveolar epithelia were also indicated. The blood vessels of alveolar septum were congested, edematous and widened, with modest infiltration of monocytes and lymphocytes. Hyaline thrombi were found in a minority of microvessels. Focal hemorrhage in lung tissue, organization of exudates in some alveolar cavities, and pulmonary interstitial fibrosis were observed. Part of the bronchial epithelia were exfoliated. Coronavirus particles in bronchial mucosal epithelia and type Ⅱ alveolar epithelia were observed under electron microscope. Immunohistochemical staining showed that part of the alveolar epithelia and macrophages were positive for 2019-nCoV antigen. Real time PCR analyses identified positive signals for 2019-nCoV nucleic acid. Decreased numbers of lymphocyte, cell degeneration and necrosis were observed in spleen. Furthermore, degeneration and necrosis of parenchymal cells, formation of hyaline thrombus in small vessels, and pathological changes of chronic diseases were observed in other organs and tissues, while no evidence of coronavirus infection was observed in these organs.Conclusions:The lungs from novel coronavirus pneumonia patients manifest significant pathological lesions, including the alveolar exudative inflammation and interstitial inflammation, alveolar epithelium proliferation and hyaline membrane formation. While the 2019-nCoV is mainly distributed in lung, the infection also involves in the damages of heart, vessels, liver, kidney and other organs. Further studies are warranted to investigate the mechanism underlying pathological changes of this disease.

Objective: To investigation HER2 status in gastric adenocarcinoma of Chinese and contributing factors to the HER2 expression. Methods: HER2 status of 40 842 gastric adenocarcinomas and clinical data were retrospectively collected from 23 hospitals dated from 2013 to 2016. The association between HER2 positivity and clinicopathologic features was analyzed. Results: Of the 40 842 patients the median age was 62 years, the male female ratio was 2.6∶1.0. The rate of HER2 positivity was 8.8% (3 577/40 842). HER2 expression was related to the tissue type, tumor location, Lauren classification and tumor differentiation (P values: 0.009, 0.001, <0.01 and <0.01, respectively). Different HER2 expression status was observed between primary and recurrent tumors in 7.6% (48/635) cases. The rates of HER2 positivity ranged from 2% to 10% among different institutions. The rates of HER2 FISH amplification were dramatically different among the 23 hospitals (0-100%) with an average rate of 10% (810/8 156) in patients with HER2 IHC 2+ . Conclusions HER2 expression is associated with clinicopathologic characteristics. HER2 re-assessment of tumor tissue and use of in situ hybridization techniques increase HER2 positivity. The current retrospective study should reflect the HER2 status in gastric adenocarcinoma of Chinese patients.

Objective To investigate the pathological feathers,diagnosis,differential diagnosis and prognosis of esophageal granular cell tumor. Methods The data of seven patients of esophageal granular cell tumor diagnosed from 2008 to 2014 in our hospital were analyzed. Seven cases of esophageal granular cell tumor were studied by hematoxylin-eosin and EliVision immunohistochemical staining,the clinical and pathological feathers were analyzed with review of the literatures. Results The pathological feathers of seven cases were very typical. The tumors located in the submucosa,and showed gray to grayish yellow,nodular,with no capsule. The size of these tumors ranged from 0. 4 ~1. 0 cm in diameter. Microscopically,the tumor cells were round,polygonal or spindle with small central nuclei and rich eosinophilic granules cytoplasm,the nucleolus could not be easily seen. Immunohistochemical stain showed that the tumor cells were positive for S-100,CD68 and NSE,but negative for SMA,Desmin,CK,CD34,CD117,DOG1,HMB45. The proportion of Ki-67 positive cells was very low. Histochemical stain showed that the tumor cells were positive for PAS. All 7 cases were benign,and the follow-up time was from 8 months to 6 years without recurrence in patients. Conclusion Granular cell tumor of esophagus is very rare in soft tissue tumors,most of which are benign and located in the middle and lower segment of esophagus. The tumor has a better prognosis. The definite diagnosis should depend on the pathological di-agnosis.

Purpose To analyze the clinical and pathological features of intracranial tumor in children. Methods 221 cases of in-tracranial tumors in children ( ages≤18 years) were retrospectively analyzed. Results The cases of intracranial tumor in children ac-counted for 7. 21% of total cases in our hospital during the same period. There is no documented gender bias. There were only 14 cases (6. 33%) with age less than 3 years old. The supratentorial tumors were 153 cases (69. 23%) and infratentorial tumors were 68 cases (30. 77%) . The most frequently affected sites were the cerebral hemispherse, sellar region, vermis and the fourth ventricle. There were 89 benign tumor and 132 malignant tumor in this series of cases. The most common five tumors were astrocytic tumors (30. 32%), embryonal tumors (19. 00%), craniopharyngiomas (11. 76%), ependymal tumors (8. 14%) and germ cell tumors (5. 88%). Conclusion The morbidity of intracranial tumors in children has increased in the recent years. The histological classifica-tion of intracranial tumors in children is multiple and it is essential to make a correct diagnosis.

Objective To explore the clinicopathological and immunohistochemical features of wolffian adnexal tumour ( WAT) . Meth-ods The clinical and pathological features analysis and immunohistochemistry methods were utilized to study the histopathology features of a case Wolffian adnexal tumor. Results One case of unilateral WAT which located in broad ligament display a solid-cystic mass with pedicled and enveloped,its histology showed large and small tubulars,screen structure and solid zone. Its immunohistochemistry staining was positive for pan-cytokeratin,vimentin,CK18 and CD99,positive staining for α-inhibin in a little tumor cell,and negative for calretinin,CD10,EMA, ER,PR,Syn,CA15-3,CA19-9,Ki-67 index is less than 5%. PAS positive staining for the basement membrane around Gland like structure. Conclusion Wolffian adnexal tumour is diagnosised by its histopathological,immunohistochemical and it’ s distinctive location where Wolffi-an duct remnants are found.

The establishment of professional master degree in pathology is a new branch of the professional degree graduate education.It is an important measure to bring the clinical pathology into the teaching system of clinical medicine specialty in China.In response to a wave of education reform in the new century, our department has positively converted the traditional postgraduate training and teaching mode, innovated the teaching idea and content, and continued to improve the teaching method and means.On the basis of fully respecting students' subject consciousness, we have combined traditional and modern teaching means, made full use of modern education information technology, actively built and promoted pathology specialized degree graduate student research, teaching and clinical trinity management: the new training mode.Through the practice of bilingual, network, clinical problems and cases of teaching and combined with the leading edge forum of famous pathologists' research and the professional standardized training of clinical pathology, we have extensively carried out the education training, which is based on the theory, practice, research, and sub specialist guidance.

Objective To analyze the clinicopathological characteristics, immunophenotypes and immu-noglobulin heavy chain gene rearrangement of gastric mucosa-associated lymphoid tissue (MALT) lymphoma. Methods The clinical data of 35 patients with gastric MALT lymphoma who had been admitted to Southwest Hospital from January 1984 to June 2003 were retrospectively analyzed. The specimens of the gastric MALT lymphoma were obtained and their pathomorphological classifications were studied. The immunophenotypes and immunoglobulin heavy chain gene rearrangement were detected by immunohistochemistry and polymerase chain reaction, respectively. All the data were analyzed by chi-square test and Mann-Whitney U test. Results The main manifestations of patients with gastric MALT lymphoma were epigastric discomfort and abdominalgia. The percentage of patients with age≥40 accounted for 74% (26/35). The gastric MALT lyrnphoma has low differentia-tion in 32 patients, and high differentiation in 3 patients. There were 31 patients in Ⅰ E stage, 2 in Ⅱ E1 stage and 2 in Ⅳ stage. Pathological examination showed that gastric MALT lymphoma was composed of centrocyte-like cells and mononuclear-like B cells or lymphoplasma cells. Twenty-nine specimens were with lymphoepithelial lesions (83%), 2 with follicular colonization (6%), and 11 with plasma cells segregated beneath the surface epithelium (33%). All the 35 specimens were B cell immunotype. Restrictive expression of κ and λ light chains of the immunoglobulin was found in 19 cases, and Bcl-2 positive expression was found in 16 cases. High expres-sion of proliferating cell nuclear antigen was found in gastric MALT lymphoma with transformed blasts, which indicated that gastric MALT lymphoma with transformed blasts was more active in proliferation than those of low grade. A monoclonal pattern of immunoglobulin heavy chain gene rearrangement was detected in 33 patients (94%). Conclusions Digestive symptoms are the main manifestations of patients with gastric MALT lymphoma. The incidence of gastric MALT lymphoma increases with age. The final diagnosis of gastric MALT lymphoma depends on the pathological, immunohistochemical examination and laboratory test.

Objective To obtain anoikis-resistant cells from human osteosarcoma cell line hFOB1.19 and investigate its biological characteristics.Methods The osteosarcoma cell line we used was malignant transformed immortalized human fetal osteoblastic human cells(hFOB1.19)which was transformed in our lab(called transformant in this paper).We have used anti-adhesion cell culture method to mimic detachment of tumor cells from extracellular matrix(ECM)to obtain anoikis-resistant variants.Transmission electron microscopy and fluorescence microscopy were used to observe the morphological changes,flow cytometry was used to observe the apoptotic rate.The growth characteristic was observed by MTT.The migration characteristics was examined by transwell cell culture system.Results Typical apoptotic cells were seen after de-adhesion culture.The apoptotic rate of the transformant at 24,48 and 72 h showed a gradually increasing tendency.The apoptotic rate of anoikis-resistant cells was lower than that of the transformant at the same time point.Compared with the transformant,the anoikis-resistant variants had stronger ability in proliferation and in migration with statistical significance(P

Objective To investigate the expressions and significance of PAX-5, OCT-2 and BOB.1 in Hodgkin lymphoma (HL). Methods Immunohistochemical method was used to detect the expressions of CD30, CD15, PAX-5, OCT-2, BOB.1, CD20 and CD3 in 44 samples of formalin-fixed, paraffin-embedded tissues of HL. The histological classification was carried out according to the WHO classification for tumors of hematopoietic and lymphoid tissues (2001). Results In all 44 cases, 3 (6.8) were nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) and 41 (93.2) were classical Hodgkin lymphoma (CHL). In Hodgkin and Reed Sternberg cells, CD30 were expressed in 36 samples (81.8), CD15 in 27 (61.4), CD20 in 14 (31.8), PAX-5 in 43 (97.7), OCT-2 in 14 (31.8), and BOB.1 in 7 (15.9). All samples of NLPHL expressed OCT-2 and BOB.1, while in the samples of CHL, 30 samples (73.2) expressed both OCT-2 and BOB.1, 7 (17.1) expressed only OCT-2, 1 (2.4) expressed only BOB.1 and all were negative for CD30. Conclusion Hodgkin lymphoma is a rare neoplasm with uncertain cause and difficult to diagnose. The detection of PAX-5, OCT-2 , BOB.1 in combination with CD30, CD15 will conduce to the diagnosis and differential diagnosis of Hodgkin lymphoma.

Objective To study the effect of neurotrophic tyrosine kinase receptor B(TrKB) on in vitro invasiveness of malignant transformed hFOB1.19 cells and the role of TrKB in invasion and metastasis of osteosarcoma.Methods Expression of TrKB in malignant transformed hFOB1.19 cells and SaOS-2 osteosarcoma cells was detected by RT-PCR and immunofluorescence.Function of TrKB of malignant transformed hFOB1.19 cells was further studied.Malignant transformed hFOB1.19 cells were treated with specific tyrosine kinase inhibitor K252a for 24 h as a treatment group,and untreated malignant transformed hFOB1.19 cells into which DMSO was added served as a control group.Morphology of cells was observed under an inverted phase contrast microscope.Cell invasiveness was detected by Transwell assays.Microfilaments of cells were detected by actin immunofluorescence.Results The expression of TrKB was significantly higher in malignant transformed hFOB1.19 cells than in SaOS-2 osteosarcoma cells(P