Objective:To study the clinicopathological features of metaplastic breast cancer (MBC) , and its prognostic factors.Methods:Data of 49 MBC cases and 30 cases of invasive ductal carcinoma (IDC) during the same period as matched control were collected. The immunohistochemistry staining of CK5/6, CK, P63, ER, HER2, Ki67 was performed in all MBC samples.Results:In MBC cases, the median age was 55 years. Median tumor size was 2.5 cm (range, 0.6-19 cm). Fifteen cases were classified as metaplastic carcinoma with heterologous mesenchymal differentiation (8 as matrix-producing carcinoma), 12 as spindle cell carcinoma, 7 as squamous cell carcinoma, 2 as low-grade adenosquamous carcinoma, 2 as fibromatosis-like metaplastic carcinoma, and 11 as mixed metaplastic carcinoma. The 5-, 10-year overall survival rate was 50%, 41%, respectively, lower than those of IDC (76%,63%) (all P<0.05). Lymph node metastasis rate, and expression of ER, PR, HER2 in MBC were lower than those in IDC (all P<0.05). Triple-negative cases in MBC were more than those of IDC ( χ2=26.244, P=0.000). The proliferative index of Ki67 was statistically different between the two groups ( t=2.624, P=0.011). Conclusions:MBC is a rare and heterogenous breast cancer. Compared to IDC, MBCs are usually larger, lower in lymph nodes metastasis, higher in proliferative index of Ki67, more triple-negative, hence with a poorer prognosis.

Objective:To investigate the clinical manifestations, imaging features, histopathological features, diagnostic pitfalls, treatment and prognosis of clear cell chondrosarcoma (CCCS).Methods:23 cases of CCCS admitted and operated from January 2010 to January 2020 were analyzed retrospectively. Among the 23 cases, 21 were males and 2 were females. There were 8 cases (35%) aged 21-40, 10 cases (43%) aged 41-60 and 5 cases (23%) aged 61-80. There were 8 femurs, 7 pelvis, 4 thoracolumbar spine, 3 sacrum and 1 tibia. The specimens were fixed with 10% phosphate-buffered formalin, decalcified with 5% nitric acid, embedded in paraffin and stained with hematoxylin and eosin (HE) and immunohistochemistry (Envision). The preoperative imaging and clinical symptoms, and the postoperative histopathological and immunophenotype under the microscope were collected. And the relevant literature was reviewed to summarize the clinical, imaging and pathomorphological characteristics of CCCS.Results:23 cases of CCCS showed bone destruction in imaging, some cases were well-circumscribed lytic lesions, some cases had sclerotic margin. The serum alkaline phosphatase was increased in 7 patients before operation. The tumor tissue was gray-white and gray-red in general and some cases showed porcelain white cartilage-like areas. Microscopically, the tumor cells are round or polygonal, some of them have clear cytoplasm and boundary, some of them are eosinophilic, some of them have round and centrally located nuclei, and mitotic image is rare. It is often seen that there are nodular distribution of cartilage-like matrix and immature woven bone, multinucleated osteoclast-like giant cell scattered in those components. Immunohistochemical staining: S-100, D2-40, EMA, Vimentin, p16, SATB2 can be positive in varying degrees. The surgical treatment is mainly through en bloc excision. 10 patients had recurrence and no distant metastasis.Conclusion:CCCS is a rare subtype of chondrosarcoma, which has low-grade malignant biological behavior and is easy to be misdiagnosed clinically and pathologically. Pathological diagnosis needs to be careful. Careful observation of microscopic histology is necessary in order to avoid over-diagnosis of osteosarcoma leading to clinical treatment errors. Once the biopsy is confirmed, it needs en bloc excision in order to reduce the recurrence rate. Long-term follow-up is needed after the operation, the overall prognosis was good.

Purpose: The unique chromosomal rearrangements of endometrial stromal sarcoma (ESS) make it possible to distinguish high-grade ESS (HGESS) and low-grade ESS (LGESS) from the molecular perspective. Analysis of ESS at the genomic and transcriptomic levels can help us achieve accurate diagnosis of ESS and provide potential therapy options for ESS patients. Materials and Methods: A total of 36 ESS patients who conducted DNA- and/or RNA-based next-generation sequencing were retrospectively enrolled in this study. The molecular characteristics of ESS at genomic and transcriptomic levels, including mutational spectrum, fusion profiles, gene expression and pathway enrichment analysis and features about immune microenvironment were comprehensively explored. Results: TP53 and DNMT3A mutations were the most frequent mutations. The classical fusions frequently found in HGESS (ZC3H7B-BCOR and NUTM2B-YWHAE) and LGESS (JAZF1-SUZ12) were detected in our cohort. CCND1 was significantly up-regulated in HGESS, while the expression of GPER1 and PGR encoding estrogen receptor (ER) and progesterone receptor (PR) did not differ significantly between HGESS and LGESS. Actionable mutations enriched in homologous recombination repair, cell cycle, and phosphoinositide 3-kinase/AKT/mammalian target of rapamycin pathways were detected in 60% of HGESS patients. Genes with up-regulated expression in HGESS were significantly enriched in five immune-related pathways. Most HGESS patients (85.7%) had positive predictors of immunotherapy efficacy. Moreover, immune microenvironment analysis showed that HGESS had relatively high immune infiltration. The degree of immune infiltration in HGESS patients with ZC3H7B-BCOR fusion was relatively higher than that of those with NUTM2B-YWHAE fusion. Conclusion This study investigated the molecular characteristics of ESS patients at the genomic and transcriptomic levels and revealed the potentially high sensitivity of targeted therapy and immunotherapy in a subset of HGESS with specific molecular features, providing a basis for guiding decision-making of treatment and the design of future clinical trials on precision therapy.

Objective:To study the clinicopathological features, diagnosis and differential diagnosis of myeloid sarcoma of the breast.Methods:Ten cases of myeloid sarcoma (MS) and 19 cases of diffuse large B cell lymphoma (DLBCL) of the breast were selected from Peking University People′s Hospital from February 2005 to September 2019. The cases were evaluated by microscopy and immunohistochemistry basing on WHO classification (2008 and 2017).Results:For the 10 cases of MS, the mean and median age was 33.8 and 31 years (range 23 to 47 years) respectively. All patients presented with breast masses; six presented with B symptoms (6/10); and LDH level was elevated in four patients. The largest tumor dimension was 1.0 to 5.3 cm (mean 2.7 cm). All 10 patients had history of acute myeloid leukemia (AML), and in one patient, the AML occurred after chemotherapy for hydatidiform mole. One case was classified as M0, four were M2, two were M4 and three were M5. For the AML, all patients received chemotherapy and nine were treated by allogeneic hematopoietic stem cell transplant (allo-HSCT) and the breast masses occurred4 months to 2 years post-transplant. Using Ann Arbor staging, five cases were stage Ⅰ, three were stage Ⅱ, and 2 were stage Ⅳ. The MS was found in the left breast (two cases); right breast (three cases) and both breasts (five cases). Lymphocyte in peripheral blood, B symptom and site of lesion had statistical significance between myeloid sarcoma and DLBCL( P<0.05). The tumor cells were primitive, expressing MPO, CD43, CD117, etc. All ten patients had follow-up information, and the median survival period was 14.4 months (range 1 to 50 months). Seven patients died. The prognosis of patients with MS was worse than DLBCL( P=0.002). Conclusions:The clinical history, pathologic morphology, immunophenotyping and molecular studies are very important for diagnosing MS tumors in the breast, and MS may occur after allo-HSCT for AML. Tumor resection, chemotherapy, radiotherapy and donor lymphocyte infusion are recommended for treatment. The prognosis is poor.

Objective:To investigate the clinicopathological, immunohistochemical and molecular features of small round cell sarcoma (SRCS) of the bone and soft tissue, and to compare the diagnostic value of different techniques.Methods:Seventy-two cases of SRCS of the bone and soft tissue diagnosed at People′s Hospital, Peking University from January 2016 to March 2020 were recruited and retrospectively analyzed for pathological morphology, immunophenotype and fluorescence in situ hybridization (FISH) data. Next generation sequencing (NGS) was performed on 13 difficult cases.Results:In the study cohort, the patients ranged in age from 4-55 years, with a male predominance. The most Ewing′s sarcomas and osteosarcomas occurred in the bone, while CIC-rearranged sarcomas, BCOR-rearranged sarcoma, synovial sarcoma, extraskeletal myxoid chondrosarcoma and FUS-NFATc2 rearranged sarcoma occurred in soft tissue. Histologically, all cases were composed predominantly of small round cells. Most cases were positive for vimentin and CD99, and showed a variable reactivity for neurogenic markers. Muscle marker and epithelial marker were negative for most cases. Combined with clinical features, histopathologic findings, immunophenotype, FISH and NGS, we diagnosed 46 Ewing sarcomas, 14 osteosarcomas, 3 CIC-rearranged sarcomas, 1 BCOR-rearranged sarcoma, 1 synovial sarcoma, 1 clear cell soft tissue sarcoma, 1 extraskeletal myxoid chondrosarcoma, 1 FUS-NFATc2 rearranged sarcoma, and 4 undifferentiated small round cell sarcomas.Conclusions:SRCS of bone and soft tissue is a group of malignant mesenchymal tumors based on morphological features. Most cases can be diagnosed with a combination of clinical characteristics, morphological features and immunohistochemical phenotype, while some cases require such further tests as FISH and NGS technologies, and NGS can be useful in diagnosing and categorizing SRCS.

Objectives: To study the significance of SATB2 expression in colon adenocarcinoma and its differential diagnosis function for ovarian metastatic adenocarcinoma. Methods: Immunohistochemistry was used to detect the expression level of SATB2 in 130 cases of colon adenocarcinoma. The relationship between the positive rate of SATB2 expression in colon cancer and clinicopathological factors was studied. Forty-seven cases of pancreatic ductal adenocarcinoma, 22 cases of cholangiocarcinoma, 46 cases of gastric adenocarcinoma, and 53 cases of ovarian mucinous adenocarcinoma were studied respectively. Results: The positive expression rate of SATB2 in 130 cases of colon adenocarcinoma is 73.8%. The SATB2 expression bears no correlation with gender, age, tumor size, location, histology type, lymph node metastasis, staging, local recurrence, distant metastasis, survival, Kras mutation, and microsatellite stability. The expression rate of SATB2 is significantly higher in well differentiated and moderately differentiated colon adenocarcinoma than that in poorly differentiated adenocarcinoma (χ²=12.804, P=0.002); the expression rate in the cases without tumor deposit is significantly higher than in cases with tumor deposit (χ²=6.485, P=0.011). There was no positive expression in all cases of pancreatic adenocarcinoma, cholangiocarcinoma, gastric adenocarcinoma, nor in ovarian mucinous adenocarcinoma. Conclusion The expression of SATB2 is associated with the differentiation of colon adenocarcinoma and the formation of tumor deposit. SATB2 can be used as an effective tumor marker for identifying colorectal cancer ovarian metastases.

Objective:To investigate the acceptance and attitude toward a novel fecal immunochemical test (FIT) in colorectal cancer screening among populations in China.Methods:From May 2018 to May 2019, 2 474 people aged 50-74 years were recruited from five provinces of China (Zhejiang, Anhui, Jiangsu, Hunan and Yunnan). The general demographic characteristics, acceptance of the new FIT technology and operational difficulties through the whole screening process were obtained through questionnaire survey. Multivariate logistic regression model was used to analyze the factors related to difficulties encountered in sampling stool, reading and uploading results.Results:The subjects were (60.0±6.4) years old, and female, high school of above educated, unemployed/retired/other, married and with medical insurance status of “new rural cooperative medical care (NRCMC)” accounted for 61.7% (1 526), 29.0%(718), 34.3% (849), 92.7% (2 293) and 31.3%(775), respectively. The population's acceptance of the FIT technology was 94.8%. In the process of FIT screening, the percentage of occurred difficulties in sampling stool, reading and uploading results were 33.1% (819), 46.4% (1 147) and 62.9% (1 557), respectively. The main difficulties were the uncertainty about whether the sampling operation was standard (28.0%), the inability to accurately judge the result displayed (32.5%) and the need for help without using a smartphone (44.2%). The results of multivariate logistic regression model analysis showed that people aged 65-74 years old and with medical insurance status of “NRCMC” were more likely to encounter difficulties in sampling, and those who were unemployed/retired/other and living with 3 or more family members were less likely to encounter difficulties in sampling. Those aged 65-74 years old, farmers or migrant workers, and those with “NRCMC” were more likely to encounter difficulties in readingresults, and those with 3 or more family members were less likely to encounter difficulties in reading result. Those with “NRCMC” were more likely to encounter difficulties in uploading results, and those with education level of high school or above, living with more than 3 family members were less likely to encounter difficulties in uploading results.Conclusion:The acceptance of the new FIT technology is relatively high among the subjects. Age, education level, occupation, number of family members living together and medical insurance status might be related to difficulties encountered in sampling stool, reading and uploading results, and it can be further strengthened in terms of the technology and characteristics of sub-populations.

Objective:To investigate the acceptance and attitude toward a novel fecal immunochemical test (FIT) in colorectal cancer screening among populations in China.Methods:From May 2018 to May 2019, 2 474 people aged 50-74 years were recruited from five provinces of China (Zhejiang, Anhui, Jiangsu, Hunan and Yunnan). The general demographic characteristics, acceptance of the new FIT technology and operational difficulties through the whole screening process were obtained through questionnaire survey. Multivariate logistic regression model was used to analyze the factors related to difficulties encountered in sampling stool, reading and uploading results.Results:The subjects were (60.0±6.4) years old, and female, high school of above educated, unemployed/retired/other, married and with medical insurance status of “new rural cooperative medical care (NRCMC)” accounted for 61.7% (1 526), 29.0%(718), 34.3% (849), 92.7% (2 293) and 31.3%(775), respectively. The population's acceptance of the FIT technology was 94.8%. In the process of FIT screening, the percentage of occurred difficulties in sampling stool, reading and uploading results were 33.1% (819), 46.4% (1 147) and 62.9% (1 557), respectively. The main difficulties were the uncertainty about whether the sampling operation was standard (28.0%), the inability to accurately judge the result displayed (32.5%) and the need for help without using a smartphone (44.2%). The results of multivariate logistic regression model analysis showed that people aged 65-74 years old and with medical insurance status of “NRCMC” were more likely to encounter difficulties in sampling, and those who were unemployed/retired/other and living with 3 or more family members were less likely to encounter difficulties in sampling. Those aged 65-74 years old, farmers or migrant workers, and those with “NRCMC” were more likely to encounter difficulties in readingresults, and those with 3 or more family members were less likely to encounter difficulties in reading result. Those with “NRCMC” were more likely to encounter difficulties in uploading results, and those with education level of high school or above, living with more than 3 family members were less likely to encounter difficulties in uploading results.Conclusion:The acceptance of the new FIT technology is relatively high among the subjects. Age, education level, occupation, number of family members living together and medical insurance status might be related to difficulties encountered in sampling stool, reading and uploading results, and it can be further strengthened in terms of the technology and characteristics of sub-populations.