Clinically relevant model of oxaliplatin-induced sinusoidal obstruction syndrome.

AIM: Sinusoidal obstruction syndrome (SOS) induced by oxaliplatin-including chemotherapies (OXCx) is associated with impaired hepatic reserve and higher morbidity after hepatic resection. However, in the absence of an appropriate animal experimental model, little is known about its pathophysiology. This study aimed to establish a clinically relevant reproducible model of FOLFOX-induced SOS and to compare the clinical/histopathological features between the clinical and animal SOS settings. METHODS: We performed clinical/pathological analyses of colorectal liver metastasis (CRLM) patients who underwent hepatectomy with/without preoperative treatment of FOLFOX (n = 22/18). Male micro-minipigs were treated with 50% of the standard human dosage of the FOLFOX regimen. RESULTS: In contrast to the monocrotaline-induced SOS model in rats, hepatomegaly, ascites, congestion, and coagulative necrosis of hepatocytes were absent in patients with CRLM with OXCx pretreatment and OXCx-treated micro-minipigs. In parallel to CRLM cases with OXCx pretreatment, OXCx-challenged micro-minipigs exhibited deteriorated indocyanine green clearance, morphological alteration of liver sinusoidal endothelial cells, and upregulated matrix metalloproteinase-9. Using our novel porcine SOS model, we identified the hepatoprotective influence of recombinant human soluble thrombomodulin in OXCx-SOS. CONCLUSIONS: With distinct differences between monocrotaline-induced rat SOS and human/pig OXCx-SOS, our pig OXCx-SOS model serves as a preclinical platform for future investigations to dissect the pathophysiology of OXCx-SOS and seek preventive strategies.

Cutaneous syncytial myoepithelioma with folliculocentric growth and EWSR1 gene rearrangement: A case report.

Cutaneous syncytial myoepithelioma is a tumor type that was initially reported in 2013 as a syncytial variant of cutaneous myoepithelioma characterized by intradermal nodular proliferation of oval to spindle-shaped tumor cells in solid and syncytial patterns. Fusion of genes Ewing sarcoma breakpoint region 1 / EWS RNA binding protein 1 (EWSR1) and pre-B cell leukemia homeobox 3 (PBX3) is found in approximately 90% of the cases. We report a case of cutaneous syncytial myoepithelioma with diagnostic difficulty due to folliculocentric morphology and atypical immunohistochemical results, including diffuse positivity of α-smooth muscle actin and claudin 4 and negative immunoreactions for epithelial membrane antigen and S100 protein. In the present case, fluorescence in situ hybridization study demonstrated EWSR1 rearrangement. We further provide a discussion of differential diagnoses with a review of relevant literature.

Eosinophilic pustular folliculitis developing at the site of COVID-19 vaccination.

We present a rare case of eosinophilic pustular folliculitis due to mRNA-based vaccines for COVID-19. Histology of the biopsy specimen was very interesting.

[A Case of Primary Testicular Mucinous Carcinoma].

A 68-year-old man presented withleft testicular painless swelling. His carbohydrate antigen 19-9 and carcinoembryonic antigen levels were elevated but his germ cell tumor markers were not high. Magnetic resonance imaging showed multiloculated cystic lesions with solid components in his left testis. Abdominal and chest computed tomography revealed multiple lung metastases, peritoneal dissemination and multiple lymph node metastases. Left high orchiectomy was performed. Histopathological examination demonstrated testicular mucinous carcinoma withsimilarity to gastric cancer. Since no tumor was found by the endoscopy of the upper gastrointestinal and the lower digestive tract, we diagnosed the patient with primary testicular mucinous carcinoma. Standard chemotherapy for gastric cancer, which consisted of tegafur, gimeracil and oteracil (TS-1) and cisplatin was administered for 16 months, and there was no progression of the disease. He died from testicular mucinous cancer 30 months after the diagnosis. In the literature, only 4 cases of testicular mucinous carcinoma have been reported. TS-1 and cisplatin are useful chemotherapeutic options for testicular mucinous carcinoma withmetastasis.

Intralymphatic histiocytosis comprises M2 macrophages in superficial dermal lymphatics with or without smooth muscles.

Intralymphatic histiocytosis represents a rare reactive disorder, which is characterized by the accumulation of macrophages within lymphatic vessels and observed predominantly in upper extremities. The infiltration and preferential M2 differentiation of macrophage are observed in chronic lymphedema, and lymphedema is considered a causative factor of intralymphatic histiocytosis. However, what causes accumulation of histiocytes in the lymphatic vessels remains unclear, and investigation regarding the characteristics of the macrophages has not been evaluated. We present a case of intralymphatic histiocytosis, in which immunohistochemical staining for both macrophages and lymphatic vessels was performed to evaluate the nature of macrophages within lymphatic vessels and to determine the causative factor. Aggregated macrophages were shown to be M2 macrophages positive for CD68, CD163 and CD206 but negative for inducible nitric oxide synthase. Thick lymphatic vessels positive for D2-40 and α-SMA in the superficial dermis were observed. We speculate that chronic lymphedema leads to hypertrophy of lymphatic vessels with smooth muscle in the superficial dermis, which may be a kind of malformation, and these lymphatic vessels produce some chemokines that induce intralymphatic aggregation of macrophages.

Exophytic Tumor Growth After Incomplete Removal of Polypoid Malignant Melanoma of the Maxillary Gingiva: A Case Report and Review of the Literature.

Polypoid malignant melanoma of the oral cavity is extremely rare. This report describes the case of the 3-time occurrence of a polypoid malignant melanoma of the maxillary gingiva in an 84-year-old woman who had removed the primary tumor by herself. The second polypoid malignant melanoma was a black 7-cm pedunculated mass surrounded by pigmented mucosa. Histologically, the tumor exhibited an ulcerated surface lined by squamous cells and contained polygonal cells with brown-and-black pigmentation. The third polypoid malignant melanoma was observed at the same location 7 months after surgery; it was a black hemorrhagic mass approximately 1.5 cm. Histologic analysis showed morphologic findings that were similar to those observed in the second polypoid melanoma. The patient died of lung metastasis 28 months after the second surgery. This report also reviews the 5 previously reported cases of polypoid malignant melanoma of the oral cavity, all of which occurred in the upper jaw. In 2 cases, initial exophytic growth of the tumor before invasion of the submucosa and relatively early detection resulted in a good prognosis. However, in 1 case, amelanotic melanoma located in the periodontal tissues was clinically misdiagnosed as epulis. Therefore, immunostaining for S-100 and HMB-45 should be considered for nonpigmented epulis-like lesions, and wide surgical resection of primary polypoid malignant melanomas at an early stage should result in a favorable prognosis.

Exacerbation of intracranial aneurysm and aortic dissection in hypertensive rat treated with the prostaglandin F-receptor antagonist AS604872.

Intracranial aneurysm (IA) and aortic dissection are both complications of hypertension and characterized by degeneration of the media. Given the involvement of prostaglandin F2α and its receptor, FP, in extracellular matrix remodeling in a mouse model of pulmonary fibrosis, here we induced hypertension and IA in rats by salt loading and hemi-lateral ligation of renal and carotid arteries and examined effects of a selective FP antagonist, AS604872, on these vascular events. AS604872 significantly accelerated degeneration of the media in both cerebral artery and aorta as evidenced by thinning of the media and disruption of the elastic lamina and promoted IA and aortic dissection. Notably, AS604872 induced expression of pro-inflammatory genes such as E-selectin in lesions and significantly enhanced macrophage infiltration. Suppression of surface expression of E-selectin with cimetidine prevented macrophage infiltration and aortic dissection. Thus, AS604872 exacerbates vascular inflammation in hypertensive rats and facilitates IA and aortic dissection. These results demonstrate that both IA and aortic dissection are caused by chronic inflammation of the arterial wall, which is worsened by AS604872, cautioning that other FP antagonists may share such deleterious actions in vascular homeostasis and suggesting that AS604872 can be used to make models of these vascular diseases with extensive degeneration.

Digestive disease management in Japan: a report on the 6th diagnostic pathology summer fest in 2012.

The 6th Diagnostic Pathology Summer Fest, held in Tokyo on August 25-26, 2012, opened its gates for everyone in the medical profession. Basic pathology training can contribute to the improvement of algorithms for diagnosis and treatment. The 6th Summer Fest with the theme 'Pathology and Clinical Treatment of Gastrointestinal Diseases' was held at the Ito International Research Center, The University of Tokyo. On August 25, 'Treatment of Early Gastrointestinal Cancer and New Guidelines' was discussed in the first session, followed by 'Biopsy Diagnosis of Digestive Tract: Key Points of Pathological Diagnosis for Inflammation and Their Clinical Significance' in the second session. On August 26, cases were discussed in the third session, and issues on pathological diagnosis and classification of neuroendorcrine tumor in the fourth session. The summaries of speeches and discussions are introduced along with the statements of each speaker. This meeting was not a formal evidence-based consensus conference, and 20 experts gave talks on their areas of specialty. Discussion was focused on how the management strategy should be standardized on the algorithm of patient care.

A quantitative trait locus responsible for inducing B-cell lymphoblastic lymphoma is a hotspot for microsatellite instability.

While the molecular mechanisms underlying microsatellite instability (MSI) have been exhaustively investigated, identifying the patterns of MSI distribution within diverse cancer genomes has remained an elusive issue. In the present study, we conducted genome-wide MSI screening in B-cell lymphoblastic lymphomas (B-LBL) which spontaneously develop in the SL/Kh strain of mice. Tumor samples harvested from 16 mice were investigated using a framework map consisting of 150 microsatellite markers spaced at increments of roughly 0.5-3.0 centimorgans, spanning the entirety of mouse chromosomes (mus musculus chromosomes [MMU]) 3-6. MMU3 contains a quantitative trait locus (QTL), Bomb1 (bone marrow pre-B1), known to induce an aberrant expansion of pre-B cells in bone marrow prior to the onset of B-LBL in SL/Kh mice. The remaining chromosomes were selected on the basis of those most closely resembling MMU3 in terms of total estimated length (maximum variance 10 Mb). MSI was confirmed at 2

Clinicopathologic features of non-small-cell lung cancer with EML4-ALK fusion gene.

BACKGROUND: A fusion gene between echinoderm microtubule-associated protein-like 4 (EML4) and the anaplastic lymphoma kinase (ALK) has recently been identified in nonsmall-cell lung cancers (NSCLCs). We screened for EML4-ALK fusion genes and examined the clinicopathological and genetic characteristics of fusion-harboring NSCLC tumors. METHODS: We examined 313 NSCLC samples from patients who underwent resection at our hospital between May 2001 and July 2005. We screened for the fusion genes using reverse-transcription polymerase chain reaction (RT-PCR) assay and confirmed the results with direct sequencing. We also examined mutations in the epidermal growth factor receptor (EGFR), KRAS, and ERBB2 genes. RESULTS: Five EML4-ALK fusion genes were detected (four from 111 female samples and one from 202 male samples; 1.6% overall). All five genes were found in adenocarcinomas and accounted for 2.4% of the 211 adenocarcinoma samples. One EML4-ALK fusion was variant 1, and two were variant 3. In addition, we also found two new fusion variants. Patients with fusion-positive tumors were nonsmokers or light smokers. Among the 211 adenocarcinomas, mutations in EGFR, KRAS, and ERBB2 were detected in 105, 29, and 7 tumors, respectively. Interestingly, all of the fusion-positive NSCLCs had no mutations within these genes. CONCLUSIONS: EML4-ALK fusion genes were observed predominantly in adenocarcinomas, in female or nonsmoking populations. Additionally, the EML4-ALK fusions were mutually exclusive with mutations in the EGFR, KRAS, and ERBB2 genes.

Trehalose dimycolate elicits eosinophilic skin hypersensitivity in mycobacteria-infected guinea pigs.

Delayed-type hypersensitivity represents high levels of protein Ag-specific adaptive immunity induced by mycobacterial infection, and can be monitored in the Ag-challenged skin. Besides protein Ags, recent evidence has suggested that a substantial immunity directed against glycolipid Ags is also elicited in response to mycobacterial infection, but skin hypersensitivity to this class of Ags has not been fully assessed. To address this issue directly, glycolipid-specific skin reactions were evaluated in guinea pigs infected with Mycobacterium avium complex (MAC). Significant skin induration was observed in MAC-infected, but not mock-infected, guinea pigs, following intradermal administration of a mixture of MAC-derived glycolipids. Surprisingly, this glycolipid-specific skin response involved up-regulated expression of IL-5 mRNA in situ and marked local infiltration of eosinophils. Challenge experiments with individual glycolipid components detected an outstanding capability for trehalose dimycolate (TDM), but not a structurally related glycolipid, glucose monomycolate, to elicit the skin response. T lymphocytes derived from the spleen of MAC-infected, but not uninfected, guinea pigs specifically responded to TDM in vitro by up-regulating IL-5 transcription, and this response was not blocked by Abs that reacted to the known guinea pig group 1 CD1 proteins. Finally, the eosinophilic skin hypersensitivity to TDM was also elicited in guinea pigs vaccinated with bacillus Calmette-Guerin, which contrasted sharply with the classical delayed-type hypersensitivity response to the purified protein derivative. Therefore, the TDM-elicited eosinophilic response defines a new form of hypersensitivity in mycobacterial infection, which may account for local infiltration of eosinophils often observed at the site of infection.

Ankyrin repeat domain 28 (ANKRD28), a novel binding partner of DOCK180, promotes cell migration by regulating focal adhesion formation.

DOCK180 is a guanine exchange factor of Rac1 originally identified as a protein bound to an SH3 domain of the Crk adaptor protein. DOCK180 induces tyrosine phosphorylation of p130(Cas), and recruits the Crk-p130(Cas) complex to focal adhesions. To understand the role of DOCK180 in cell adhesion and migration, we searched for DOCK180-binding proteins with a nano-LC/MS/MS system, and identified ANKRD28, a protein that contains twenty-six ankyrin domain repeats. Knockdown of ANKRD28 by RNA interference reduced the velocity of migration of HeLa cells, suggesting that this protein plays a physiologic role in the DOCK180-Rac1 signaling pathway. Furthermore, knockdown of ANKRD28 was found to alter the distribution of focal adhesion proteins such as Crk, paxillin, and p130(Cas). On the other hand, expression of ANKRD28, p130(Cas), Crk, and DOCK180 induced hyper-phosphorylation of p130(Cas), and impaired detachment of the cell membrane during migration. Consequently, cells expressing ANKRD28 exhibited multiple long cellular processes. ANKRD28 associated with DOCK180 in an SH3-dependent manner and competed with ELMO, another protein bound to the SH3 domain of DOCK180. In striking contrast to ANKRD28, overexpression of ELMO induced extensive lamellipodial protrusion around the entire circumference. These data suggest that ANKRD28 specifies the localization and the activity of the DOCK180-Rac1 pathway.

Non-specific interstitial pneumonia as a manifestation of graft-versus-host disease following pediatric allogeneic hematopoietic stem cell transplantation.

Bronchiolitis obliterans (BO) is generally believed to be a marker of pulmonary manifestation of graft-versus-host disease (GVHD) in patients who have undergone bone marrow transplantation for hematological malignancy. Pulmonary manifestations reported as GVHD (other than BO) include lymphocytic bronchiolitis with cellular interstitial pneumonia, lymphoid interstitial pneumonia, veno-occlusive disease, and diffuse alveolar damage. Morphological reactions in the lungs of bone marrow transplant recipients associated with interstitial pneumonia have not been described systematically. Reported herein is a fibrosing non-specific interstitial pneumonia (NSIP) pattern together with BO in both lungs in an 8-year-old girl following a second allogeneic hematopoietic stem cell transplantation for relapsed neuroblastoma of adrenal origin. The course was complicated by bilateral pneumothoraces, and the patient underwent lung transplantation 3 years after the second stem cell transplantation. Because the patient had chronic GVHD of the skin and the liver preceeded by the development of pulmonary involvement, NSIP may represent one of the facets of pulmonary GVHD.

A large cystic gastrointestinal stromal tumor of the rectum in the retrorectal space.

A 54-year-old man presented with pain on defecation and rectal bleeding. Colonoscopy revealed a submucosal tumor extending from the lower rectum to the upper rim of the anal canal, which compressed the rectal wall inward by two thirds of its circumference. Magnetic resonance images demonstrated a 70 × 80-mm unilocular cystic mass with a solid portion in the periphery in the retrorectal space, which displaced the rectum anterolaterally. The peripheral solid portion was hypointense on T2-weighted images and not hyperintense on diffusion-weighted images, suggesting low cellularity of the lesion. Cytological examination of the clear and serous fluid obtained by transrectal biopsy showed the presence of normal columnar and squamous epithelial cells and the absence of malignant cells. Therefore, the cystic retrorectal mass was presumed to be tailgut cysts rather than gastrointestinal stromal tumors (GISTs). The mass and rectum were extirpated en bloc with an adequate surgical margin by laparoscopic intersphincteric resection. Pathologically, spindle tumor cells proliferated with nuclear palisading and were strongly immunopositive for c-kit, leading to a final diagnosis of rectal GIST. There are no reports describing a huge, cystic rectal GIST arising in the retrorectal space, which should be considered in the differential diagnosis of cystic retrorectal lesions.

Xanthogranulomatous cholecystitis complicated with primary sclerosing cholangitis: report of a case.

Patients with primary sclerosing cholangitis (PSC) are at an increased risk for biliary tract carcinoma. The preoperative diagnosis of a biliary tract tumor as a malignancy is difficult, even using new modalities such as multidetector computed tomography (MD-CT), magnetic resonance cholangiopancreatography (MRCP), endoscopic retrograde cholangiography (ERC), and (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET). Surgery is considered to be first line of treatment when these examinations suggest the presence of malignancy in the biliary tract, depending on both the curability of the cancer and the impaired liver function due to PSC. The management of gallbladder masses in patients with PSC remains problematic due to difficulties with the precise diagnosis and adequate surgery. Xanthogranulomatous cholecystitis (XGC) is a type of chronic cholecystitis, and sometimes coexists with gallbladder cancer. It is very difficult to make a preoperative diagnosis differentiating these two diseases. This report presents the case of a patient with XGC, who had been suspected of having gallbladder cancer before surgery, because the tumorous lesion emerged within a year and showed a focally increased uptake by FDG-PET during the follow up for PSC for years. This is the first case of XGC discovered during treatment for PSC.

Loss of heterozygosity on 10q23 is involved in metastatic recurrence of hepatocellular carcinoma.

We performed loss of heterozygosity (LOH) analysis on five chromosomal arms (1p, 3p, 9p, 10q, 17p) in hepatocellular carcinoma (HCC). Univariate analyses of 80 patients who underwent liver transplantation demonstrated significant correlations between cancer recurrence and the following variables: LOH on 3p26, LOH on 10q23, LOH on 17p13, tumor diameter > or = 5 cm, number of tumors > or = 4, histologic Grade 3, alpha-fetoprotein (AFP) > or = 400 ng/mL, American Joint Committee on Cancer (AJCC) pT classification, and portal invasion. Patients with LOH on 10q23 exhibited a significantly higher 3-year recurrence rate (38.9%vs 11.9%, P = 0.0009). Multivariate analysis identified LOH on 10q23, histologic Grade 3, tumor nodules > or = 4, and AFP > or = 400 ng/mL as the risk factors of advanced HCC recurrence. These results suggest that LOH on 10q23 is associated with metastatic recurrence of HCC.

Allograft steatohepatitis in progressive familial intrahepatic cholestasis type 1 after living donor liver transplantation.

We studied histological features and long-term outcomes in patients with progressive familial intrahepatic cholestasis type 1 (PFIC1) after liver transplantation (LT). Histological findings were correlated with the post-LT course and treatment in 11 recipients with PFIC1. Ages at LT varied from 1 to 18 years (median, 4 years). Macrovesicular steatosis was observed in 8 patients at a median of 60 days post-LT (range, 21-191 days). Severe steatosis progressed to steatohepatitis in 7 patients at a median of 161 days (range, 116-932 days). The patients were followed up for a median of 7.3 years (range, 2.3-16.1 years). Six showed bridging fibrosis, with 2 progressing to cirrhosis. One patient with cirrhosis died because of the rupture of a splenic artery aneurysm 13.6 years post-LT. Post-LT refractory diarrhea was present in all 8 having steatosis. Three without post-LT diarrhea showed no allograft steatosis. Bile adsorptive resin therapy reduced the diarrhea and steatosis. Patients with posttransplant steatosis typically had more severe mutations of the ATPase class I type 8B member 1 (ATP8B1) gene and were more likely to have systemic complications such as pancreatitis. In conclusion, allograft steatosis was present in patients with PFIC1, progressing to steatohepatitis and cirrhosis. Because expression of the familial intrahepatic cholestasis 1 gene occurs in several organs, including the small intestine, pancreas, and liver, and it is involved in enterohepatic bile acid circulation, post-LT steatosis may be due to a malfunction of the ATP8B1 product.

Intracerebral schwannoma in a child with infiltration along perivascular spaces resembling meningioangiomatosis.

Schwannoma arising within brain parenchyma is a rare lesion, usually found in children. Reported herein is a case of intracerebral schwannoma in a 5-year-old boy, with a review of the English-language literature on the subject, in which 47 cases were found. Few detailed histological reviews of intracerebral schwannoma exist. The tumor had a distinctive plexiform growth pattern, and small aggregates of Schwann cells spread extensively into the surrounding brain tissue along perivascular spaces adjacent to the tumor nodule. Histological differential diagnoses included perivascular schwannosis and meningioangiomatosis. A few intratumoral axons, seen on immunostaining for neurofilament protein, were trapped at the periphery of the main lesion, but there was no evidence of intralesional axons in the multiple nodules of Schwann cell proliferations that extended into the perivascular spaces, suggesting that the lesions are neoplastic. Because Schwann cells are not a natural component of the central nervous system, the origin of intracerebral schwannomas remains unknown. The histology suggests that Schwann cells of the perivascular nerve plexus are a likely site of origin.

A comparative study of pathological staging systems in predicting recurrent hepatocellular carcinoma after liver transplantation.

BACKGROUND/PURPOSE: The applicability of the staging systems of hepatocellular carcinoma (HCC) to liver transplantation (LT) has not been fully evaluated. Therefore, we compared the HCC recurrence after LT as predicted by various staging systems, including the American Joint Committee on Cancer (AJCC) system 5th edition, the AJCC system 6th edition, the American Liver Tumor Study Group (ALTSG) system, and the Liver Cancer Study Group of Japan (LCSGJ) system. METHODS: A total of 108 patients who had HCC were classified according to these systems. We compared cumulative recurrence curves, recurrence-free survival curves, and overall survival curves of the systems estimated by Kaplan-Meier method. We compared cumulative event rates among different stages with the log-rank test for each staging system. RESULTS: The log-rank test showed that the cumulative recurrence rates were different among different stages with a statistical significance for the staging systems except for the AJCC 5th edition system. Cumulative recurrence curves by the AJCC 6th edition system and the LCSGJ system showed better visual separation than the other two systems. With respect to recurrence-free survival and overall survival, no staging systems showed significant discriminative power. CONCLUSIONS: The current AJCC tumor-node-metastasis staging and the LCSGJ system are superior in predicting HCC recurrence after LT.