ZFTA::RELA fusion in a distinct liposarcoma morphologically overlapping with chondroid lipoma.

Chondroid lipoma is a rare benign adipose tumor characterized by a recurrent ZFTA::MRTFB fusion. Herein, we report an unusual liposarcoma that partly exhibited overlapping features with those of chondroid lipoma and harbored a ZFTA::RELA fusion. A 59-year-old man presented with a shoulder mass that had existed for approximately 8 years and with increasing pain due to a pelvic mass. The 5.8-cm resected shoulder tumor partly consisted of nests and strands of variably lipogenic epithelioid cells within a hyalinized or focally chondromyxoid stroma, indistinguishable from chondroid lipoma. The histological pattern gradually transitioned to highly cellular, stroma-poor, diffuse sheets of cells with greater nuclear atypia and mitotic activity. Vascular invasion and necrosis were present. The metastatic pelvic tumor revealed a similar histology. Despite multimodal treatment, the patient developed multiple bone metastases and succumbed to the disease 14 months after presentation. Targeted RNA sequencing identified an in-frame ZFTA (exon 3)::RELA (exon 2) fusion, which was confirmed by reverse transcription-polymerase chain reaction, Sanger sequencing, and break-apart fluorescent in situ hybridization assays. The tumor showed a different histology from that of ependymoma, no brain involvement, and no match with any sarcoma types or ZFTA::RELA-positive ependymomas according to DNA methylation analysis. p65 and L1CAM were diffusely expressed, and a CDKN2A/B deletion was present. This is the first report of an extra-central nervous system tumor with a ZFTA::RELA fusion. The tumor partly displayed an overlapping histology with that of chondroid lipoma, suggesting that it may represent a hitherto undescribed malignant chondroid lipoma with an alternative ZFTA fusion.

A Novel Mouse Model of Nonalcoholic Steatohepatitis Suggests that Liver Fibrosis Initiates around Lipid-Laden Macrophages.

While the interaction of cells such as macrophages and hepatic stellate cells is known to be involved in the generation of fibrosis in nonalcoholic steatohepatitis (NASH), the mechanism remains unclear. This study employed a high-fat/cholesterol/cholate (HFCC) diet to generate a model of NASH-related fibrosis to investigate the pathogenesis of fibrosis. Two mouse strains: C57BL/6J, the one susceptible to obesity, and A/J, the one relatively resistant to obesity, developed hepatic histologic features of NASH, including fat deposition, intralobular inflammation, hepatocyte ballooning, and fibrosis, after 9 weeks of HFCC diet. The severity of hepatic inflammation and fibrosis was greater in A/J mice than in the C57BL/6J mice. A/J mice fed HFCC diet exhibited characteristic CD204-positive lipid-laden macrophage aggregation in hepatic parenchyma. Polarized light was used to visualize the Maltese cross, cholesterol crystals within the aggregated macrophages. Fibrosis developed in a ring shape from the periphery of the aggregated macrophages such that the starting point of fibrosis could be visualized histologically. Matrix-assisted laser desorption/ionization mass spectrometry imaging analysis detected a molecule at m/z 772.462, which corresponds to the protonated ion of phosphatidylcholine [P-18:1 (11Z)/18:0] and phosphatidylethanolamine [18:0/20:2 (11Z, 14Z)], in aggregated macrophages adjacent to the fibrotic lesions. In conclusion, the HFCC diet-fed A/J model provides an ideal tool to study fibrogenesis and enables novel insights into the pathophysiology of NASH-related fibrosis.

Verification of the Impact of Blood Glucose Level on Liver Carcinogenesis and the Efficacy of a Dietary Intervention in a Spontaneous Metabolic Syndrome Model.

Metabolic syndrome (MS) is a risk factor for type 2 diabetes mellitus, vascular inflammation, atherosclerosis, and renal, liver, and heart diseases. Non-alcoholic steatohepatitis (NASH) is a progressive representative liver disease and may lead to the irreversible calamities of cirrhosis and hepatocellular carcinoma. Metabolic disorders such as hyperglycemia have been broadly reported to be related to hepatocarcinogenesis in NASH; however, direct evidence of a link between hyperglycemia and carcinogenesis is still lacking. Tsumura Suzuki Obese Diabetic (TSOD) mice spontaneously develop metabolic syndrome, including obesity, insulin resistance, and NASH-like liver phenotype, and eventually develop hepatocellular carcinomas. TSOD mice provide a spontaneous human MS-like model, even with significant individual variations. In this study, we monitored mice in terms of their changes in blood glucose levels, body weights, and pancreatic and liver lesions over time. As a result, liver carcinogenesis was delayed in non-hyperglycemic TSOD mice compared to hyperglycemic mice. Moreover, at the termination point of 40 weeks, liver tumors appeared in 18 of 24 (75%) hyperglycemic TSOD mice; in contrast, they only appeared in 5 of 24 (20.8%) non-hyperglycemic mice. Next, we investigated three kinds of oligosaccharide that could lower blood glucose levels in hyperglycemic TSOD mice. We monitored the levels of blood and urinary glucose and assessed pancreatic lesions among the experimental groups. As expected, significantly lower levels of blood and urinary glucose and smaller deletions of Langerhans cells were found in TSOD mice fed with milk-derived oligosaccharides (galactooligosaccharides and lactosucrose). At the age of 24 weeks, mild steatohepatitis was found in the liver but there was no evidence of liver carcinogenesis. Steatosis in the liver was alleviated in the milk-derived oligosaccharide-administered group. Taken together, suppressing the increase in blood glucose level from a young age prevented susceptible individuals from diabetes and the onset of NAFLD/NASH, as well as carcinogenesis. Milk-derived oligosaccharides showed a lowering effect on blood glucose levels, which may be expected to prevent liver carcinogenesis.

Two Ectopic Liver Lobes Discovered Incidentally at an Autopsy: A Case Report.

The ectopic liver lobe is a rare anomaly and is most frequently reported as a solitary mass. Herein, we report a case of multiple (two) ectopic liver lobes detected at an autopsy. A Japanese man in his 70s died of an infectious disease associated with acquired immunodeficiency syndrome (AIDS). Autopsy revealed the incidental finding of two 1-cm masses, located anterior to the inferior vena cava. Both masses were composed of liver tissue and had internal microscopic structures resembling the porta hepatis, consisting of an outflow bile duct and blood vessels. The outflow bile duct appeared to be continuous with the common bile duct, but the connection point of the outflow vessel was unclear. The liver tissue showed fibrous thickening of the central veins and portal venopathy, including fibrosis in the portal area as well as narrowing and loss of the portal veins. There was no evidence of congestion, fibrosis, biliary stasis, or neoplasm. The incidence of hepatocellular carcinoma is higher in the ectopic liver lobe than in the proper liver, presumably due to the abnormal circulation and bile excretion pathways. The patient also presented with portal venopathy; this suggests the presence of abnormal circulatory dynamics.

Accumulation of α-synuclein in hepatocytes in nonalcoholic steatohepatitis and its usefulness in pathological diagnosis.

BACKGROUNDS: Nonalcoholic steatohepatitis (NASH) is characterized by fat deposition, inflammation, and hepatocellular damage. The diagnosis of NASH is confirmed pathologically, and hepatocyte ballooning is an important finding for definite diagnosis. Recently, α-synuclein deposition in multiple organs was reported in Parkinson's disease. Since it was reported that α-synuclein is taken up by hepatocytes via connexin 32, the expression of α-synuclein in the liver in NASH is of interest. The accumulation of α-synuclein in the liver in NASH was investigated. Immunostaining for p62, ubiquitin, and α-synuclein was performed, and the usefulness of immunostaining in pathological diagnosis was examined. METHODS: Liver biopsy tissue specimens from 20 patients were evaluated. Several antibodies against α-synuclein, as well as antibodies against connexin 32, p62, and ubiquitin were used for immunohistochemical analyses. Staining results were evaluated by several pathologists with varying experience, and the diagnostic accuracy of ballooning was compared. RESULTS: Polyclonal α-synuclein antibody, not the monoclonal antibody, reacted with eosinophilic aggregates in ballooning cells. Expression of connexin 32 in degenerating cells was also demonstrated. Antibodies against p62 and ubiquitin also reacted with some of the ballooning cells. In the pathologists' evaluations, the highest interobserver agreement was obtained with hematoxylin and eosin (H&E)-stained slides, followed by slides immunostained for p62 and α-synuclein, and there were cases with different results between H&E staining and immunostaining CONCLUSION: These results indicate the incorporation of degenerated α-synuclein into ballooning cells, suggesting the involvement of α-synuclein in the pathogenesis of NASH. The combination of immunostaining including polyclonal α-synuclein may contribute to improving the diagnosis of NASH.

Histological and immunohistochemical analysis of epithelial cells in epidermoid cysts in intrapancreatic accessory spleen.

BACKGROUND: Epidermoid cysts in intrapancreatic accessory spleen (ECIPAS) are a rare lesion. Its pathogenesis, including the origin of cystic epithelium, is not well established. We aimed to elucidate new aspects of the pathological features of ECIPAS to clarify its pathogenesis. METHODS: Six cases of ECIPAS were included in this study. As well as histopathological analysis, to elucidate the features and nature of cystic epithelial cells, immunohistochemical analysis including Pbx1 and Tlx1 and imaging mass spectrometry was performed. RESULTS: Histologically, the cysts were covered by either monolayered or multilayered epithelium. Immunohistochemistry revealed that the epithelial cells in multilayered epithelium exhibited different attributes between the basal and superficial layers. Few epithelial cells had abundant clear cytoplasm and were immunohistochemically positive for adipophilin, suggesting lipid-excreting function. The intracystic fluid contained cholesterol clefts and foamy macrophages, and imaging mass spectrometry revealed the accumulation of lipids. Immunohistochemical analysis indicated that the epithelial cells were positive for Pbx1 in some cases. CONCLUSION: Novel histological features of epithelial cells of ECIPAS were indicated. Although more cases need to be evaluated, we propose that the cause of ECIPAS may be different from that of pancreatic ductal origin. J. Med. Invest. 70 : 251-259, February, 2023.

Triple-negative breast cancer and basal-like subtype†: Pathology and targeted therapy.

Triple-negative breast cancer (TNBC) is a heterogenous disease. For personalized medicine, it is essential to identify and classify tumor subtypes to develop effective therapeutic strategies. Although gene expression profiling has identified several TNBC subtypes, classification of these tumors remains complex. Most TNBCs exhibit an aggressive phenotype, but some rare types have a favorable clinical course. In this review, we summarize the classification and characteristics related to the various TNBC subtypes, including the rare types. Therapeutic methods that are suitable for each subtype are also discussed. Of the intrinsic breast cancer subtypes identified by gene expression analysis, the basal-like subtype specifically displayed decreased expression of an estrogen receptor (ER) and human epidermal growth factor receptor 2 (HER2) cluster. We also present results that characterize the TNBC and basal-like phenotypes. TNBC may be categorized into four major classes : basal-like, immune-enriched, mesenchymal, and luminal androgen receptor. Therapeutic strategies for each subtype have been proposed along with newly approved targeted therapies for TNBC, such as immune checkpoint inhibitors. Understanding the classification of TNBC based on gene expression profiling in association with clinicopathological factors will facilitate accurate pathological diagnosis and effective treatment selection. J. Med. Invest. 68 : 213-219, August, 2021.

Neonatal streptozotocin treatment rapidly causes different subtype of hepatocellular carcinoma without persistent hyperglycemia in 4CS mice fed on a normal diet.

Although diabetes mellitus (DM) is a well-known risk factor for hepatocellular carcinoma (HCC), the underlying mechanisms have not yet to be defined. We previously reported that DIAR mice fed with standard murine diet developed type 1 diabetes and HCC at age of 16 weeks old with a neonatal streptozotocin treatment (n-STZ). Because DIAR mice did not manifest obesity nor develop steatohepatitis, hyperglycemia with streptozotocin trigger or streptozotocin alone might turn on the hepato-carcinogenesis. An insulin-recruitment to DIAR-nSTZ mice showed an increased frequency of HCC during the first 12 weeks of age, although the diabetic indications notably improved. To elucidate the role of hyperglycemia in hepato-carcinogenesis, we performed a head-to-head comparative study by using 4CS mice and DIAR mice with n-STZ treatment. Newborn 4CS mice and DIAR mice were divided into STZ treated group and control group. The blood glucose levels of DIAR-nSTZ mice increased at age of eight weeks, while that of 4CS-nSTZ mice were maintained in the normal range. At eight weeks old, three out of five DIAR-nSTZ mice (60%) and one out of ten 4CS-nSTZ mice (10%) developed multiple liver tumors. At age of 12 weeks old, all eight of DIAR-nSTZ mice (100%) and two of 10 4CS-nSTZ mice (20%) developed multiple liver tumors. At 16 weeks old, all animals of DIAR-nSTZ and 4CS-nSTZ mice occurred liver tumors. DIAR-nSTZ showed hyperglycemia and HCC, and 4CS-nSTZ developed HCC without hyperglycemia. These results were interpreted that the onset of HCC maybe not related to the presence or absence of hyperglycemia but nSTZ treatment. On the other hand, since the carcinogenesis of 4CS-nSTZ is delayed compared to DIAR-nSTZ, hyperglycemia may play a role in the progression of carcinogenesis. Histologically, the liver tumor appeared irregularly trabecular arrangements of hepatocytes with various degrees of nuclear atypia. By immunohistochemical analyses, all liver tumors showed positive staining of glutamine synthetase (GS), an established human HCC marker. The expression pattern of GS was divided into a strong diffuse pattern and weak patchy pattern, respectively. The liver tumor showing the weak GS-patchy pattern expressed biliary/stem markers, EpCAM, and SALL4, partially. Because 4CS-nSTZ mice did not show any metabolic complications such as gaining body weight or high blood glucose level, it is a unique animal model with a simple condition to investigate hepatic carcinogenesis by excluding other factors.

Applying Probe Electrospray Ionization Mass Spectrometry to Cytological Diagnosis: A Preliminary Study by Using Cultured Lung Cancer Cells.

OBJECTIVES: Cytology and histology are 2 indispensable diagnostic tools for cancer diagnosis, which are rapidly increasing in importance with aging populations. We applied mass spectrometry (MS) as a rapid approach for swiftly acquiring nonmorphological information of interested cells. Conventional MS, which primarily rely on promoting ionization by pre-applying a matrix to cells, has the drawback of time-consuming both on data acquisition and analysis. As an emerging method, probe electrospray ionization-MS (PESI-MS) with a dedicated probe is capable to pierce sample and measure specimen in small amounts, either liquid or solid, without the requirement for sample pretreatment. Furthermore, PESI-MS is timesaving compared to the conventional MS. Herein, we investigated the capability of PESI-MS to characterize the cell types derived from the respiratory tract of human tissues. STUDY DESIGN: PESI-MS analyses with DPiMS-2020 were performed on various type of cultured cells including 5 lung squamous cell carcinomas, 5 lung adenocarcinomas, 5 small-cell carcinomas, 4 malignant mesotheliomas, and 2 normal controls. RESULTS: Several characteristic peaks were detected at around m/z 200 and 800 that were common in all samples. As expected, partial least squares-discriminant analysis of PESI-MS data distinguished the cancer cell types from normal control cells. Moreover, distinct clusters divided squamous cell carcinoma from adenocarcinoma. CONCLUSION: PESI-MS presented a promising potential as a novel diagnostic modality for swiftly acquiring specific cytological information.

Endurance exercise training inhibits activity of plasma GOT and liver caspase-3 of mice [correction of rats] exposed to stress by induction of heat shock protein 70.

A single bout of exercise increases production of heat shock protein 70 (HSP70), which protects cells against various stresses. In this study, we investigated whether endurance exercise training enhances liver level of HSP70 and, if so, whether HSP70 contributes to hepatic protection against stress in vivo. Mice of an exercise-training group performed 60 min of treadmill running 5 days/wk for 4 wk. The resting level of liver HSP70 was 4.5 times higher in the trained than in sedentary mice. After 4 wk of exercise training, both groups of mice were exposed to the following stresses: 1) heat stress, 2) cold stress, 3) oxidative stress, 4) ethanol stress, and 5) exercise stress by compelling the mice to run on a treadmill until exhausted. After exposure to the stresses, the liver was immediately isolated. Elevation of liver HSP70 in the trained mice was evident, whereas no elevation was found in the sedentary mice. On exposure to heat, diethyldithiocarbamate and ethanol, activities of glutanic oxalacetic transaminase in plasma, and liver caspase-3, a key enzyme of apoptotic processing, were elevated in the sedentary mice but not in the trained mice. These results suggest that exercise training enhanced the resting level of liver HSP70 and hepatic protection against various stresses, at least partly attributing to the suppression of caspase-3 activity by the increase in HSP70.