During the past decate, Chinese pathologists have made remarkable achievements in the area of soft tissue tumors. They have not only done in-depth researches in selected entities like liposarcoma and round cell sarcomas, but have also issued expert consenses and guideline, as well as published professional books and translation books, with purpose to comprehensively improve the level of diagnosis nationwide.

Over the past decade, the field of bone tumor pathology in China has made remarkable progress. These achievements are reflected not only in the innovation and standardization of diagnostic techniques, which have significantly improved diagnostic accuracy, but also in the in-depth exploration of tumor pathogenesis and the continuous refinement of treatment protocols. More than one hundred research papers on bone tumor pathology published in the Chinese Journal of Pathology stand as a testament to the relentless efforts and practical contributions of Chinese pathologists in this field. On the occasion of the Chinese Journal of Pathology′s 70th anniversary, we summarize the progress in bone tumor pathology while also looking forward to the future, aiming to promote greater advancements in this field.

During the past decate, Chinese pathologists have made remarkable achievements in the area of soft tissue tumors. They have not only done in-depth researches in selected entities like liposarcoma and round cell sarcomas, but have also issued expert consenses and guideline, as well as published professional books and translation books, with purpose to comprehensively improve the level of diagnosis nationwide.

Over the past decade, the field of bone tumor pathology in China has made remarkable progress. These achievements are reflected not only in the innovation and standardization of diagnostic techniques, which have significantly improved diagnostic accuracy, but also in the in-depth exploration of tumor pathogenesis and the continuous refinement of treatment protocols. More than one hundred research papers on bone tumor pathology published in the Chinese Journal of Pathology stand as a testament to the relentless efforts and practical contributions of Chinese pathologists in this field. On the occasion of the Chinese Journal of Pathology′s 70th anniversary, we summarize the progress in bone tumor pathology while also looking forward to the future, aiming to promote greater advancements in this field.

Objective:To investigate the radiologic, pathologic, and molecular features of simple bone cysts (SBC), and their differential diagnoses.Methods:Fourteen cases of SBC were collected at the Department of Pathology, the First Affiliated Hospital of Nanjing Medical University from 2017 to 2022, and fluorescence in situ hybridization (FISH) was performed for retrospective analysis.Results:There were 14 patients, including 7 females and 7 males, with age range of 7 to 45 (median 29) years. The most common complaint was pain, including 4 cases with pathological fracture and 5 with history of previous trauma. The tumor size ranged from 3.4 to 13.5 (median 5.6) cm. The lesion involved the femur ( n=4), humerus ( n=5) and iliac bone ( n=5). Radiologic diagnoses included SBC, aneurysmal bone cyst, and giant cell tumor of the bone or its combination with aneurysmal bone cyst-like region and fibrous dysplasia. Histologically, the cyst walls of the lesions were composed of fibrous tissue, fibrin-like collagen deposits, bone-like matrix and occasional woven bone. The lesional cells were spindled to ovoid, with scattered osteoclast-like giant cells, foamy histiocytes, hemosiderin deposits and cholesterol clefts. In 6 cases there were nodular fasciitis-like areas. Immunohistochemically, the spindled to ovoid cells were positive for SMA, EMA and SATB2 in varying degrees. FISH detection was performed in all 14 cases and EWSR1/FUS rearrangement were found in 9 cases. One case of FUS::NFATC2 fusion was detected by next-generation sequencing. Nine cases of SBC with the rearrangement were more cellular, and there were more mitotic figures in the recurrent FUS::NFATC2 fusion tumor. Clinical follow-up was obtained in all 14 cases with the time ranging from 5 to 105 (mean 46) months. Amongst them, the tumor with FUS::NFATC2 rearrangement had local recurrence twice after the first local excision, but had no more recurrence or metastasis 34 months after the subsequent segmental resection. The other 13 cases had no recurrence. Conclusions:EWSR1 or FUS rearrangement is most commonly identified in SBC, suggesting that SBC might be a neoplastic disease. In cases where the radiologic appearance and histomorphology are difficult to differentiate from aneurysmal bone cyst, FISH detection can aid in the definitive diagnosis.

Objective To explore the effects of lung rehabilitation using Spiro-tiger training apparatus on the respiratory mechanics and airway remodeling in patients with chronic obstructive pulmonary disease(COPD)in stable stage.Methods Ninety-three stable COPD patients admitted to Nanxiang Branch of Shanghai Ruijin Hospital were randomly divided into control group(46 cases)and observation group(47 cases).Control group was treated with the training for pursed lips breathing and abdominal breathing,and observation group was trained with Spiro-tiger training apparatus in addition to the treatment given to control group.Both groups were intervened continuously for 9 weeks.The two groups were compared in terms of respiratory mechanics(respiratory frequency,tidal volume,minute ventilation,and peak respiratory pressure),airway remodeling[matrix metalloproteinase-9(MMP-9),vascular endothelial growth factor(VEGF),and transforming growth factor-β1(TGF-β1)],and lung function[forced vital capacity(FVC),forced expiratory volume in the first second(FEV1),and FEV1/FVC],blood gas analysis indexes[arterial partial pressure of oxygen(PaO2),arterial partial pressure of carbon dioxide(PaCO2)],6-minute walking distance(6MWD)and health status[Borg scale and St.George's respiratory questionnaire(SGRQ)].The patients were followed up for 6 months,and the incidence of acute exacerbation of COPD was recorded.Results After 9 weeks of intervention,compared with control group,observation group had lower peak respiratory frequency and respiratory pressure,and higher tidal volume(P<0.05).There was no significant difference in minute ventilation between two groups(P>0.05).The levels of MMP-9,VEGF,TGF-β1 and PaCO2 were lower,and FVC,FEV1,FEV1/FVC and PaO2 were higher in observation group than in control group(P<0.05).Observation group had longer 6MWD,and lower Borg score and SGRQ score as compared with control group(P<0.05).After 6-month follow-up,the incidence of COPD acute exacerbation in observation group was lower than that in control group(4.26%vs19.57%,P<0.05).Conclusion Lung rehabilitation using Spiro-tiger training apparatus can effectively improve respiratory mechanics,lung function,blood gas analysis indexes and health status in stable COPD patients,alleviate airway remodeling,and avoid acute exacerbation of COPD.

Objective:To investigate the clinicopathological diagnosis and differential diagnosis of inflammatory myofibroblastic tumor (IMT).Methods:Thirty-two cases of IMT collected at the People′s Hospital of Jiangsu Province from May 2010 to May 2020 were evaluated for their clinical, histologic, immunohistochemical and genomic features, and relevant literature was reviewed.Results:There were 19 male and 13 female patients, with age ranging from 5 to 65 years (mean, 37 years). The tumors were located in the lung and mediastinum (10 cases), gastrointestinal tract and mesentery/omentum (12 cases), urinary bladder (5 cases), head and neck (3 cases), somatic soft tissue (1 case), and retroperitoneum (1 case). Four cases of epithelioid inflammatory myofibroblastic sarcoma (EIMS) were all located intra-abdominally. Histologically, the tumor cells were myofibroblasts and fibroblasts arranged in predominantly fusiform pattern, with variably edematous to myxoid background or sclerotic collagenized stroma, and variably mixed chronic or acute inflammatory cells infiltration. EIMS were composed mainly of epithelioid tumor cells, with myxoid stroma and numerous neutrophils. Immunohistochemically, the tumor cells expressed cytoplasmic ALK (25/32, 78%), whereas the four EIMS showed nuclear membrane ALK staining pattern. The tumor cells also expressed CKpan (8/19), SMA (24/32, 75%) and desmin (12/32, 38%); all four EIMS also showed strong positivity for desmin. Fluorescence in situ hybridization (FISH) for ALK gene rearrangement showed split apart signals in 12 of 15 cases, most commonly with atypical signals. Next-generation sequencing (NGS) was performed in three tumors and showed that one case of lower leg IMT harbored a novel CLIP2-ALK fusion, and two cases of EIMS harbored RANBP2-ALK fusion. Follow-up data were available in 29 patients. Twenty-two patients were alive with no evidence of tumor, four patients had tumor recurrences (three patients were treated with crizotinib and were alive with tumor), and three patients died of the disease (including two patients with EIMS).Conclusions:IMTs show a wide morphologic spectrum, and should be differentiated form a variety of benign or malignant tumors. Immunohistochemistry (ALKp80, ALKD5F3) and FISH (ALK break-apart probe) could assist the diagnosis of IMT, with NGS recommended for the atypical cases.

Objective:To investigate the clinicopathological and molecular features, diagnosis and differential diagnosis of TFE3-rearranged epithelioid hemangioendothelioma (EHE). Methods Two cases of TFE3-rearranged EHE arising from soft tissues, diagnosed by the Pathology Department of the First Affiliated Hospital of Nanjing Medical University from 2013 to 2020 were observed. EnVision method was used for immunophenotyping, fluorescence in situ hybridization (FISH) was used to test TFE3 gene rearrangements and WWTR1-CAMTA1 fusion gene,and next-generation sequencing (NGS) was used to delineate the fusion transcripts.Results:Details of these two cases were as follows: case 1, male, 51 years old, with tumor in the right temporal region; case 2, female, 42 years old, with tumor in the right neck. The tumors showed progressive painless enlargement. Grossly, the tumor of case 1 was multinodular with unclear boundary and grayish red cut surface, while the tumor of case 2, originating from a vein, appeared as a firm, tan mass within vessel wall. Microscopically, both tumors showed moderate cellularity and were consisted of plump, epithelioid, or histiocytoid cells with eosinophilic cytoplasm and mild-to-moderate nuclear pleomorphism. Most of the tumor cells were arranged in solid or alveolar growth patterns, while some tumor cells showed intraluminal papillary growth pattern in case 1 and anastomosing vascular channels and extramedullary hematopoiesis in case 2. Immunohistochemically, the tumor cells showed diffuse positivity for CD31, CD34, ERG, and TFE3. FISH revealed TFE3 break-apart signals in two cases, but WWTR1-CAMTA1 gene fusion was not detected. NGS identified YAP1 (exon1)-TFE3 (exon6) fusion gene in case 2. Clinical follow-up information was available in both cases for a follow-up period of 15 and 59 months respectively. Patient 1 had a relapse 22 months after surgery, and was currently alive with the tumor. Patient 2 remained disease-free.Conclusions:TFE3-rearranged EHE is a rare molecular subtype of EHE, with accompanying characteristic morphologic features. However the morphologic spectrum remains under-recognized, and more experience is needed. Immunohistochemical and molecular examinations are helpful for the diagnosis and differential diagnosis of the disease.

Objective:To investigate the clinicopathological characteristics, genetic features, diagnosis and differential diagnosis of pulmonary artery intimal sarcoma (PAIS).Methods:Three cases of PAIS were collected from Jiangsu Province People′s Hospital (from February 2016 to November 2019). The clinical data, imaging examination, morphology, immunostaining, and molecular changes were retrospectively analyzed.Results:There were 1 male and 2 females (age: 32, 50, 60 years), who had symptoms of cough, asthma or chest tightness. Imaging findings indicated low density filling defects which were suspected as thrombus, embolism or myxoma. Grossly, the main tumor was located in the elastic arteries and their lobar branches, also extended into the atrium and ventricle, with lung parenchymal infiltration focally. Microscopically, tumor cells were predominantly composed of abundant spindle cells with obvious atypia and myxoid background, resembling fibroblastic or myofibroblastic differentiation. Active mitotic figures and necrosis could be seen in some areas. Immunohistochemical staining of vimentin was strongly positive, while pan-cytokeratin, S-100, desmin, Fli-1, CD31, SMA and ERG etc were variably positive only in focal areas. FISH detection showed amplification of MDM2 gene in three cases and EGFR gene in two cases. Metastatic lesions were found in one case by 18, 32 and 42 months after surgery respectively. There was no recurrence or metastasis in the other two cases.Conclusions:PAIS is one of exceptionally poor differentiated mesenchymal tumor that arises from the arterial intima of elastic pulmonary arteries. There was no definite differention in morphology. Gene detection shows amplification of MDM2 and EGFR gene. This tumor often has poor prognosis with aggressive behavior. Complete resection is the only effective therapeutic option. There is disagreement as to whether chemotherapy and radiotherapy can improve survival.

Objective:To study the clinicopathological features of large B-cell lymphoma (LBCL) with IRF4 rearrangement.Methods:Seven cases of LBCL with IRF4 rearrangement collected at the First Affiliated Hospital of Nanjing Medical University from November 2018 to October 2019 were evaluated by hematoxylin and eosin staining, immunohistochemistry and fluorescence in situ hybridization detection. The relevant literature was reviewed.Results:Four tumors were located in the tonsils, 2 tumors in the lymphoid nodes and one tumor in the adenoid.The patients were 3 males and 4 females patients with a median age of 24 years (range, 6 to 39 years).Microscopically, entirely follicular pattern was present in one case, entirely diffuse pattern in 2 cases, and follicular and diffuse pattern in other 4 cases. The tumor cells were medium to large in size and showed the morphology of centroblasts or blastoid cells with irregular nuclei, brisk mitotic activity in 3 cases and starry sky in 2 cases. All of the cases were positive for CD20, PAX-5, bcl-6, and MUM1 and had a Ki-67 index>80%, while CD10 and bcl-2 were positive in 3 cases. IRF4 gene rearrangement was identified in all cases and bcl-6 gene rearrangement in 2 cases. All patients presented with localized disease with clinical stage Ⅰ or Ⅱ, except one with stage Ⅳ at presentation and a new lesion in the mediastinum developed 8 months later.Conclusions:LBCL with IRF4 rearrangement is a clinicopathologically distinct entity. The observations reveal a broader spectrum of morphology and biological behaviors. The relationship between clinical stage and prognosis needs to be determined in more cases.