[Erdheim-Chester disease initially discovered at extraskeletal locations: a clinicopathological analysis of four cases]

Objective: To investigate the clinicopathological features of Erdheim-Chester disease (ECD) initially diagnosed at extraskeletal locations. Methods: Clinical and pathological data of four cases of ECD diagnosed initially in extraskeletal locations were collected at Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, from January 2013 to June 2023. BRAF V600E gene was detected by reverse transcription polymerase chain reaction (RT-PCR). Pertinent literatures were reviewed. Results: Four ECD patients included two males and two females ranging in ages from 2 years 11 months to 69 years. The lesions located in the lung (two cases), central nervous system (one case), and the testicle (one case) were collected in the study. One patient had occasional fever at night, one had nausea and vomiting, and two were asymptomatic. Radiologically, the two pulmonary ECD showed diffuse ground-glass nodules in both lungs, and the lesions in central nervous system and testicle both showed solid masses. Microscopically, there were infiltration of foamy histiocyte-like cells and multinucleated giant cells in a fibrotic background, accompanied by varying amounts of lymphocytes and plasma cells. The infiltration of tumor cells in pulmonary ECD was mainly seen in the subpleural area, interlobular septa, and perivascular and peribronchiolar areas. The fibrosis was more pronounced in the pleura and interlobular septa, and less pronounced in the alveolar septa. Immunohistochemical staining showed that all tumor cells expressed CD68, CD163 and F􀃼a; one case showed S-100 expression; three cases were positive for BRAF V600E; all were negative for CD1α and Langerin. RT-PCR in all four cases showed BRAF V600E gene mutation. Conclusions: Extraskeletal ECD is often rare and occult, and could be easily misdiagnosed, requiring biopsy confirmation. The radiologic findings of pulmonary ECD is significantly different from other types of ECD, and the histopathological features of pronounced infiltration in the subpleura area, interlobular septa, perivascular and peribronchiolar areas can be helpful in the differential diagnosis from other pulmonary diseases. Detection of BRAF V600E gene mutation by RT-PCR and its expression by immunohistochemical staining are also helpful in the diagnosis.

[Clinicopathological features and HER2 expression of metaplastic squamous cell carcinoma of the breast]

Objective: To investigate the clinicopathological features and HER2 expression of metaplastic squamous cell carcinoma (MSCC) of the breast. Methods: A total of 47 MSCC cases diagnosed in the Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China from January 2010 to December 2021 were reviewed. The clinical information (including the follow-up data of HER2 positive patients) and pathological features were collected and analyzed. Results: All of the patients were female. Among the 47 cases, 25 were pure squamous cell carcinoma (PSCC) and 22 were mixed metaplastic carcinoma with squamous cell component (MMSC). The median age of the patients was 54 years (range, 29-84 years). The maximum diameter of the mass ranged from 0.8 to 10.0 cm, with a mean value of 3.3 cm, 85.7% (24/28) of the cases were smaller than 5 cm, and only 4 cases were larger than or equal to 5 cm. 89.5% of the MMSC presented with a solid mass. Cystic changes were more commonly found in the PSCC group (50%, P<0.05) than the MMSC group. 36.7% (11/30) of the patients had lymph node metastasis at the time of diagnosis. The squamous cell carcinoma component in all cases showed diffuse or patchy expression of p63, p40 and CK5/6. 55.3% (26/47) of the cases showed triple-negative phenotype. Among the 7 HER2-positive patients, 6 were MMSC group, which had a significantly higher rate of HER2-positivity than that in the PSCC group (1 case). In 1 MMSC case, immunohistochemistry showed HER2 2+in the invasive ductal carcinoma component and HER2 negativity (0) in the squamous cell carcinoma component, but HER2 FISH was negative in invasive ductal carcinoma and positive in squamous cell carcinoma component. Six HER2-positive MSCC patients received anti-HER2-targeted therapy, including two patients who received neoadjuvant chemotherapy combined with anti-HER2-targeted therapy before surgery. One patient achieved pathological complete remission, while the other achieved partial remission (the residual tumors were squamous cell carcinoma components). After 9-26 months of follow-up, four patients had no disease progression, two patients developed pulmonary metastases, and one patient showed local recurrence. Conclusions: MSCC is a group of heterogeneous diseases. PSCC and MMSC may be two different entities. Most of the MSCC are triple-negative and HER2 positivity is more commonly seen in MMSC with invasive ductal carcinoma component. Some HER2-positive MSCC patients can achieve complete remission or long-term progression-free survival after receiving anti-HER2 targeted therapy, but the squamous cell carcinoma component may be less sensitive to targeted therapy than the invasive ductal carcinoma component.

[Pathological changes of the spleen in ten patients with coronavirus disease 2019(COVID-19) by postmortem needle autopsy]

Objective: To study the pathological changes of the spleen in patients with COVID-19 and to analyze the relationship between the weakened immune system and splenic lesions. Methods: Postmortem needle autopsies from the spleen were carried out on 10 patients who died from COVID-19 in Wuhan. Routine hematoxylin and eosin (HE) staining was used to observe the pathological changes. The changes of lymphocytes were studied further with immunohistochemistry.RT-PCR was used to detect 2019-nCoV RNA in the spleen. In addition,the Epstein-Barr virus (EBV) was detected by in situ hybridization, and coronavirus particles were detected by transmission electron microscopy in 2 cases. Results: There were 7 males and 3 females, with an average age of 68.3 years.Of the 10 cases, 4 had cancer history and another 4 had other underlying diseases respectively.Cough, fever, malaise and dyspnea were the main clinical symptoms.The time from onset to death was 15-45 days.Ten cases patients had normal or slight increase in peripheral blood leukocyte count in the early stage of the disease, 6 cases had significant increase before death. Five patients' peripheral blood lymphocyte count decreased in the early stage of the disease, and 10 patients' peripheral blood lymphocyte count decreased significantly before the disease progressed or died. Seven cases were treated with corticosteroid (methylprednisolone ≤40 mg/d, not more than 5 days). Histopathological examination showed that the cell composition of the spleen decreased, white pulp atrophied at different levels, meanwhile lymphoid follicles decreased or absent;in addition, the ratio of red pulp to white pulp increased with varying degrees. In 7 cases, more neutrophil infiltration was found, and in 5 cases, scattered plasma cell infiltration was found. Macrophage proliferation and hemophagocytic phenomena in a few cells were found in a case. Meanwhile, necrosis and lymphocyte apoptosis were detected in 2 cases, small artery thrombosis and spleen infarction in 1 case, and fungal infection in 1 case. The results of immunohistochemistry showed that the T and B lymphocyte components of the spleen in all cases decreased in varying degrees. CD20(+) B cells were found to accumulate in the lymphoid sheath around the splenic artery in 8 cases. However, CD20 and CD21 immunostaining in 2 cases showed that the number of white pulp was almost normal, and splenic nodules were atrophic. CD3(+), CD4(+) and CD8(+)T cells were decreased. In 9 cases,CD68(+) macrophages were no significant changes in the distribution and quantity. While more CD68(+) cells were found in the medullary sinuses of 1 case (related to fungal infection). Few CD56(+) cells were found. EBV was negative by in situ hybridization. RT-PCR was used to detect the nucleic acid of 2019-nCoV. One of 10 cases was positive, 39 years old,who was the youngest patient in this group, and the other 9 cases were negative. Coronavirus particles were found in the cytoplasm of macrophage under electron microscope in 2 cases. Conclusions: The death of COVID-19 occurs mainly in the elderly, and some cases have no underlying diseases. Spleen may be one of the organs directly attacked by the virus in some patients who died from COVID-19. T and B lymphocyte in the spleen decrease in varying degrees, lymphoid follicles are atrophied, decreased or absent, and the number of NK cells do not change significantly. And the pathological changes of the spleen are not related to the use of low dose corticosteroid, which may be related to the direct attack of virus and the attack of immune system on its own tissues.

Morphology and Isothermal Crystallization Kinetics of Polypropylene/Poly(ethylene-co-vinyl alcohol) Blends

Polypropylene (PP)/poly(ethylene-co-vinyl alcohol) (EVOH) blends were prepared by melt blending using PP-g-MAH as a compatabilizer. The microstructure and rheological behavior of PP/EVOH blends were studied. The results showed the that EVOH particles were uniformly dispersed in the PP matrix and inhibited the mobility of PP chains. The isothermal crystallization kinetics and morphology development of PP/EVOH blends were compared with that of pure PP. It was found that the EVOH essentially acted as an effective nucleating agent for PP, which could significantly increase the nucleation rate because the EVOH molecules in PP/EVOH blends aggregated together to form interface. Therefore, the introduction of EVOH increased the overall rate of isothermal crystallization compared with pure PP, although the PP molecular chains would be hindered seriously if excessive amounts of EVOH were added. X-ray diffraction showed that pure PP and PP/EVOH blends exhibited an identical crystal structure, and the crystallinity of the PP phase in the blends was not significantly different from that of pure PP.

Effects of Cooling Ways on the Structure of Polypropylene Hollow Fiber Membranes Prepared by Stretching

Air, water, and DINCH (Di-isononyl-cyclohexane-1,2-dicarboxylate) were selected as the cooling media to prepare polypropylene hollow fiber membranes by melt spinning. The effects of various cooling ways with different cooling rates on the row-nucleated lamellar crystallization were investigated. The crystallinity, orientation and arrangement of the crystals were examined by differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), and small-angle X-ray scattering (SAXS). Membrane morphology was observed by SEM. The less uniform pores, a layer of amorphous phase, and only a small part of slit-shaped pores were observed on the surface of samples when water and DINCH were used as the heat transfer medium because the fast cooling rate froze the surface molecules and decreased the crystallinity and orientation. However, when air was used as the cooling medium, the higher crystallinity and the better orientation of the annealed hollow fibers were obtained mainly due to the slow cooling rate. Corresponding hollow fiber membranes prepared by stretching had better interconnectivity of pores and larger pure water flux. Thus this study explains why air was selected as the cooling medium to prepare polypropylene hollow fiber membranes which can have larger pure water flux. Also, it provides new insights into the structure control of polypropylene hollow fiber membranes by stretching in order to prepare membranes with high strength.

Effect of Spin-Draw Rate and Stretching Ratio on Polypropylene Hollow Fiber Membrane Made by Melt-Spinning and Stretching Method

A series of polypropylene hollow fiber membranes was fabricated by melt-spinning and stretching. The crystalline behavior and hard elasticity of precursor hollow fibers were studied by differential scanning calorimetry (DSC), elastic recovery and strain-stress curves. The structure and properties of membranes were investigated in detail by scanning electron microscopy (SEM), optical microscopy, pure water flux, and so on. The results showed that membranes with excellent structure and properties can be obtained at a spin-draw rate of 350 m/min and a stretching ratio of 200 %. The evolution of crystal structure was explored during the annealing and stretching processes by two-dimensional small-angle X-ray scattering (2D-SAXS). Shish-kebab structure was obtained during annealing for hollow fibers at a spin-draw rate of 350 m/min. The crystalline lamellae were destroyed and micropores were formed during the fabrication of membranes by stretching.