Retiform hemangioendothelioma of the breast in a man with 18F-flurodeoxyglucose accumulation on positron emission tomography: a case report.

BACKGROUND: Retiform hemangioendothelioma (RH) is a rare, intermediate-grade vascular tumor that often arises in the trunk and extremities. The clinical and radiological features of RH remain largely unknown. CASE PRESENTATION: A male patient in his 70s presented with shortness of breath on exertion, and computed tomography incidentally revealed a tumor in his right breast. Positron emission tomography (PET) revealed moderate 18F-fluorodeoxyglucose (FDG) uptake in the tumor. RH was observed in the resected specimens. Three months after surgery, the patient was free of local recurrence and distant metastasis. CONCLUSIONS: RH was found in the male breast and was accompanied by FDG uptake on PET. PET may be useful in diagnosing RH. Although metastasis is rare in RH, local recurrence may occur, and careful follow-up is required.

Clinicopathologic and Immunohistochemical Findings from Autopsy of Patient with COVID-19, Japan.

An autopsy of a patient in Japan with coronavirus disease indicated pneumonia lung pathology, manifested as diffuse alveolar damage. We detected severe acute respiratory syndrome coronavirus 2 antigen in alveolar epithelial cells and macrophages. Coronavirus disease is essentially a lower respiratory tract disease characterized by direct viral injury of alveolar epithelial cells.

[Case of Peritoneal Dissemination from Gastrointestinal Stromal Tumor of Jejunum Treated with Repeated Non-Curative Surgery].

A 71-year-old male presented with abdominal distension and fever to our hospital. Abdominal CT revealed a huge tumor in abdomen, and non-curative surgery was performed. Peritoneal dissemination was widespread and the tumor invaded the bladder and sigmoid-colon mesenterium. Two months after the initial surgery, CT showed liver metastasis, and oral administration of imatinib mesylate was started. The peritoneal dissemination and liver metastasis showed a decrease, and this was well controlled for 45 months without severe side effects. Abdominal CT revealed peritoneal dissemination in the ileocecum after 43 months since the administration of imatinib. Therefore, sunitinib treatment was initiated. After 3 months of sunitinib administration, the tumor perforated. Emergency operation was performed to resect the ileocecum, and sunitinib was continued for 1 year. In GIST with liver metastasis and peritoneal dissemination, repeated surgical resection combined with chemotherapy is important to improve the patient's survival.

Correlation Between Telomere Attrition of Zona Fasciculata and Adrenal Weight Reduction in Older Men.

CONTEXT: Although numerous theories are reported on sex differences in longevity, the underlying biological mechanisms remain unknown. We previously reported that telomere length in the zona reticularis cells of the human adrenal cortex was significantly longer in older than that in younger subjects. However, we could not evaluate sex differences in the telomere lengths. OBJECTIVE: To compare the telomere lengths of adrenocortical and adrenal medullar cells between men and women from infancy through older adulthood. METHODS: Adrenal glands of 30 male (aged 0 to 100 years) and 25 female (aged 0 to 104 years) autopsied subjects were retrieved from autopsy files. Using quantitative fluorescence in situ hybridization, relative telomere lengths were determined in the parenchymal cells of the 3 adrenocortical zones and medulla. Age-related changes in the weight of adrenal glands were also investigated. MAIN RESULTS: Older male subjects (aged 65 years or older) had significantly shorter telomere lengths in zona fasciculata (ZF) cells compared to the corresponding female subjects. In men, older subjects exhibited a significant age-related reduction in adrenal weight; however, no age-related changes in adrenal weight were detected in women. CONCLUSION: Telomere attrition of ZF cells was correlated with adrenal weight reduction in older men but not in older women, suggesting a decreased number of ZF cells in older men. This may help us understand the possible biological mechanisms of sex difference in longevity of humans.

Correlation Between Differentiation of Adrenocortical Zones and Telomere Lengths Measured by Q-FISH.

CONTEXT: Adrenocortical zonation is associated with a markedly complex developmental process, and the pathogenesis and/or etiology of many disorders of adrenocortical zonal development have remained unknown. Cells from the three adrenocortical zones are morphologically and functionally differentiated, and the mature stage of cell development or senescence has been recently reported to be correlated with telomere length. However, the telomere length of each adrenocortical zonal cell has not yet been studied in human adrenal glands. OBJECTIVE: We aimed to study the telomere lengths of adrenocortical parenchymal cells from three different zones of the adrenal glands present during childhood, adolescence, and adulthood. METHODS: Adrenal glands of 30 autopsied subjects, aged between 0 and 68 years, were retrieved from pathology files. The normalized telomere to centromere ratio (NTCR), an index of telomere length, was determined in the parenchymal cells of the zona glomerulosa, zona fasciculata, and zona reticularis (ZR), using quantitative fluorescence in situ hybridization. RESULTS: NTCR of ZR cells was the longest, followed in decreasing order by that of zona glomerulosa and zona fasciculata cells in subjects aged 20 to 68 years, but no substantial differences in NTCR were detected among these three zones in the group <20 years of age. NTCR of ZR increased with age in subjects aged 20 to 68 years, whereas no important age-dependent changes in NTCR were detected in the group <20 years of age. CONCLUSION: The telomere lengths for three zones in adrenal cortex were correlated with their differentiation in adulthood but not in childhood and adolescence.

Age and CD20 Expression Are Significant Prognostic Factors in Human Herpes Virus-8-negative Effusion-based Lymphoma.

Human herpes virus-8 (HHV-8)-negative effusion-based lymphoma (HHV-8-negative EBL) can be distinguished from primary effusion lymphoma based on clinical and pathologic findings. Although the morphology between the 2 is similar and they both originate from body cavities with serous effusions and are characterized by lack of tumor masses, HHV-8-negative EBL generally occurs in older patients, and has favorable response to therapy and better prognosis than primary effusion lymphoma. However, no systematic studies have investigated prognostic factors in patients with HHV-8-negative EBL. In this report, clinical and pathologic characteristics of 67 cases of HHV-8-negative EBL, including 2 of our own cases, were analyzed. Univariate analyses revealed older age (70 y and above), Japanese ethnicity, pericardial effusion, CD20 expression, and chemotherapy with rituximab were significantly favorable prognostic factors. Peritoneal effusion was identified as an unfavorable prognostic factor. In the multivariate analysis, age and CD20 expression were independent prognostic factors (P=0.013 and 0.003, respectively). A past history of induced fluid overload, hepatitis C viral infection, and peritoneal effusion were significantly correlated with patients aged below 70 years, while pericardial and pleural effusions were significantly correlated with patients aged 70 years and above. A comparison of cases with and without CD20 expression revealed that Japanese ethnicity and pericardial effusion were significantly correlated with CD20 expression, whereas a past history of induced fluid overload and peritoneal effusion were significantly correlated with the absence of CD20. We concluded that older age and CD20 expression are significant and favorable independent prognostic factors of HHV-8-negative EBL.

Gastric lipomatosis treated by total gastrectomy: a case report.

BACKGROUND: Gastric lipomatosis is characterized by multiple gastric lipomas or a diffuse gastric infiltration of the submucosal or subserosal layer by the adipose tissue; diffuse-type gastric lipomatosis is an extremely rare condition. Here, we present the case of a patient with gastric lipomatosis treated by total gastrectomy. CASE PRESENTATION: A 54-year-old man diagnosed with gastric submucosal tumor in 2008 was referred to our hospital for further examination and treatment in September 2016. Upper gastrointestinal endoscopy revealed a submucosal tumor with an associated ulcer on the anterior wall of the lower body of the stomach. A compressing mass was observed on the anterior wall of the greater curvature and the posterior wall of the stomach. Following a biopsy of the submucosal tumor and ulcer, lipoma without malignancy was diagnosed by microscopy. A giant gastric lipoma was suspected because endoscopic ultrasound revealed a high-echoic lesion on the antral wall that extended to the stomach. Therefore, total gastrectomy was performed, and gastric lipomatosis was confirmed by a histological examination of the resected specimen. CONCLUSIONS: Surgical treatment is a highly effective treatment for symptomatic gastric lipomatosis with extensive involvement or multiple lipomas and can be used for patient diagnosis.

Outcomes after resection of occupational cholangiocarcinoma.

BACKGROUND: Cholangiocarcinoma caused by exposure to 1,2-dichloropropane and/or dichloromethane is recognized as occupational cholangiocarcinoma. The aim of this study was to investigate the outcomes after resection of occupational cholangiocarcinoma to establish a treatment strategy for this disease. METHODS: Clinicopathological findings and outcomes after surgical intervention in 20 patients with occupational cholangiocarcinoma were investigated. RESULTS: Of 20 the patients, curative resection was performed in 16 patients. Three patients underwent radiation at the stump of the bile ducts. Adjuvant chemotherapy was performed in 12 patients. Biliary intraepithelial neoplasia, intraductal papillary neoplasm of the bile duct, and/or chronic bile duct injury was detected in most subjects. Intraabdominal infection developed after surgery in nine patients. Cholangiocarcinoma recurred in 12 of the 20 patients. The recurrent tumors in five patients developed at a different part of the bile duct from the primary tumor and a second resection was performed in four of these five patients. CONCLUSIONS: The incidence of postoperative complications including intraabdominal infection was high in patients with occupational cholangiocarcinoma. Multicentric recurrence occurred not infrequently after surgery because the bile ducts had a high potential for the development of carcinoma. The aggressive treatment including second resection for the multicentric recurrence appeared to be effective.

Clonorchis sinensis ova in bile juice cytology from a patient with severe hyperbilirubinemia and portal vein thrombosis.

Infection with the trematode Clonorchis sinensis is the most common human fluke infection in East Asian populations. Although this infection is associated with obstructive jaundice or choledocholithiasis, portal vein thrombosis has not been reported. Here, we report the first case of a 60-year-old man who had both C. sinensis infection and portal vein thrombosis with severe hyperbilirubinemia (75.4 mg/dl). He initially presented with abdominal pain and jaundice. Computed tomography revealed gallstones, common bile duct calculus, and thrombus in the left main branch of the portal vein. A nasobiliary tube was inserted under endoscopic retrograde cholangiography. Cytology of the bile juice revealed many C. sinensis eggs. The abdominal pain and jaundice improved following choledocholithotomy and combination treatment with a chemotherapeutic agent and anti-coagulant. This case suggests that inflammation around the portal vein as a result of C. sinensis infection has the potential to evoke portal vein thrombosis. Such cases should be treated with both a chemotherapeutic agent and anti-coagulant therapy. In conclusion, the possibility of infection with C. sinensis should be considered in patients presenting with hyperbilirubinemia and portal vein thrombosis, particularly in East Asian populations.

Sigmoid volvulus is associated with a decrease in enteric plexuses and ganglion cells: a case-control study.

PURPOSE: Although sigmoid volvulus (SV) causes acute obstruction, its pathogenesis and mechanism of torsion are unknown, and few reports have described its pathological findings. Here, we evaluated the clinicopathological characteristics of volvulus and factors contributing to volvulus of the sigmoid colon. METHODS: We compared 14 patients with SV (10 men and 4 women; median age, 78.5 years) with 14 age- and sex-matched control patients for differences in clinical characteristics, focusing on dysmotility (enteric visceral myopathy, neuropathy, and mesenchymopathy). RESULTS: Of the 14 SV patients, 7 had recurrent volvulus, 11 had an associated condition, and 5 required emergency surgery. Atrophy and fibrosis of the inner muscle were more prevalent in the SV than control patients (p = 0.041). Median extent (per centimeter of muscularis propria) of the myenteric plexus (12.5 versus 17.5, p < 0.001) and submucous plexus (15.0 versus 25.5, p < 0.001) was lower in the SV patients, as were the median numbers of myenteric (9.7 versus 30.4, p < 0.001) and submucous ganglion cells (10.0 versus 23.2, p < 0.001). Inflammatory neuropathy was more prevalent in the SV than control patients (p = 0.046); whereas, the prevalence of mesenchymopathy did not differ (p = 0.481). CONCLUSIONS: A decrease in the extent of enteric plexus and ganglion cells precedes the clinical manifestation of SV. Although further elucidation is needed, this decrease may play an important role in the diagnosis of SV and in identifying the mechanism leading to torsion in SV.

Immunohistochemical study of pseudohypertrophy of the inferior olivary nucleus.

OBJECTIVE: Pathogenesis of pseudohypertrophy of the inferior olivary nucleus (PH-IO) was analyzed based on immunohistochemical study. METHODS: Immunostained medullas with PH-IO were observed with confocal laser microscopy. RESULTS: αB-crystallin (αBC) was frequently expressed in the neurons and co-localized with microtubule-associated protein 2 (MAP2). The neurons were occasionally positive for SMI-31. αBC and SMI-31 were co-localized in some neurons. Synaptophysin (SYP)-immunoreactive dots were present around MAP2-positive hypertrophic neurons and hypertrophic thick neurites. Periphery-stained Lys-Asp-Glu-Leu (KDEL)-positive neurons were shown. Central chromatolytic neurons were found with Klüver-Barrera staining, which indicated that the rough endoplasmic reticulum (ER) was distributed to the periphery of the cytoplasm. CONCLUSIONS: αBC prevents microtubule disassembly and phosphorylation of the neurofilaments under stressful conditions. Our results indicated that αBC protected microtubules and neurofilaments in PH-IO. The retrograde transport of KDEL receptors from the Golgi complex to the ER is increased under stressful conditions. We considered that KDEL receptors were retro-transported to ER, and then the ER containing KDEL receptors was distributed to the periphery of the cytoplasm. PH-IO showed various immunohistochemical changes due to trans-synaptic degeneration.

[Sustained remission of blastic plasmacytoid dendritic cell neoplasm with ABVD chemotherapy].

Blastic plasmacytoid dendritic cell neoplasm is a rare but clinically aggressive tumor known to be derived from the precursors of plasmacytoid dendritic cells with frequent cutaneous involvement. Though the majority of patients initially respond to multi-agent chemotherapy, most cases without hemopoietic stem cell transplantation relapse within a year. We describe a case of a 71-year-old man with a dark-purple subcutaneous nodule (5×3 cm) under his right auricle. Histologic examination of the excisional biopsy specimen revealed a diffuse proliferation of blast cells with irregular nuclei, fine chromatin and one to several small nucleoli in the dermis extending to the subcutaneous soft tissues. The tumor cells expressed CD123, CD56, CD4, CD7, LCA, and TdT but not CD3, CD20, CD79a, CD10, CD68, CD163, myeloperoxidase (MPO), or naphthol-ASD-chloroacetate (ASD-Ch) esterase. A diagnosis of blastic plasmacytoid dendritic cell neoplasm was made. He did not have any other lesions except for the solitary skin nodule. He had refractory cytopenia with multilineage dysplasia (RCMD) and renal dysfunction. It was difficult for him to receive hemopoietic stem cell transplantation because of his advanced age and renal dysfunction. We had previously experienced successful treatment with ABVD chemotherapy for interdigitating dendritic cell sarcoma after ineffective CHOP chemotherapy. The plasmacytoid dendritic cell is one of the precursor cells of the interdigitating dendritic cell. Therefore we tried to apply ABVD therapy to him. The first course of ABVD induced complete remission. Although the therapies were reduced and postponed because of various complications, he is now in complete remission that has lasted for 21 months. Although previously not reported, ABVD therapy is useful for patients with blastic plasmacytoid dendritic cell neoplasm who cannot receive hemopoietic stem cell transplantation.

Histopathological and immunohistochemical findings of 20 autopsy cases with 2009 H1N1 virus infection.

Twenty autopsy cases with 2009 pandemic influenza A (2009 H1N1) virus infection, performed between August 2009 and February 2010, were histopathologically analyzed. Hematoxylin-eosin staining, immunohistochemistry for type A influenza nucleoprotein antigen, and real-time reverse transcription-PCR assay for viral RNA were performed on formalin-fixed and paraffin-embedded specimens. In addition, the D222G amino acid substitution in influenza virus hemagglutinin, which binds to specific cell receptors, was analyzed in formalin-fixed and paraffin-embedded trachea and lung sections by direct sequencing of PCR-amplified products. There were several histopathological patterns in the lung according to the most remarkable findings in each case: acute diffuse alveolar damage (DAD) with a hyaline membrane (four cases), organized DAD (one case), acute massive intra-alveolar edema with variable degrees of hemorrhage (three cases), neutrophilic bronchopneumonia (five cases) and tracheobronchitis with limited histopathological changes in alveoli (four cases). In two cases, the main findings were due to preexisting disease. Influenza virus antigen was only detected in the respiratory tract in 10 cases by immunohistochemistry. The antigen was detected in type II pneumocytes (three cases) in the epithelial cells of the trachea, bronchi and glands (six cases), and in the epithelial cells in both of the above (one case). The four cases with acute DAD presented with antigen-positive type II pneumocytes. In one case, the D222G substitution was detected in the lung as a major sequence, although 222D was prominent in the trachea, suggesting that selection of the viral clones occurred in the respiratory tract. In five cases, the pathogenesis of 2009 H1N1 was confirmed to be viral infection in pneumocytes, which caused severe alveolar damage and fatal viral pneumonia. Further studies on both host and viral factors in autopsy or biopsy materials will be essential to elucidate the other pathogenic factors involved in influenza virus infection.

[A case of lipoma of the lesser omentum with torsion of the pedicle in a twenty-eight-year-old woman].

A 28-year-old woman was admitted to our hospital with abdominal pain. Abdominal CT scan demonstrated a well-demarcated heterogeneous lipid tumor about 8 cm in diameter anterior to the stomach. Abdominal ultrasonography (US) revealed a low echoic mass without enhancement of vascular images. We made a diagnosis of the lipoma, but not excluding the possibility of a liposarcoma, or the torsion of a tumor. We performed an operation to remove the tumor. Finally the tumor was diagnosed as a lipoma of the lesser omentum with torsion of the pedicle. This is the third reported case of torsion of a lipoma. In addition, this case is considered as the first such case of lipoma of the lesser omentum.

[History of the histological staining survey in the Tokyo Metropolitan Hospital].

The Tokyo metropolitan hospital society of chief medical technologist has carried out a staining survey once a year since 1992. This staining survey is performed to plan improvements of the staining technology at each hospital and reduction of differences among hospitals. This report describes the examination results for PAS stain, Papanicolaou stain, and PAM stain.

[Solitary brain metastasis of thyroid papillary carcinoma mimicking a cavernous angioma by MRI].

We report a case of a brain metastasis of thyroid papillary carcinoma. A 50-year-old man suffered generalized convulsion. MRI showed a mixed intensity mass with a perifocal low intensity rim in T2WI, mimicking cavernous angioma. The patient underwent craniotomy and total removal of the mass. The resected specimen revealed thyroid papillary carcinoma. Further examination showed a mass in his thyroid gland. Other distant metastases were not revealed. This is a case of a solitary brain metastasis of thyroid papillary carcinoma and the patient's initial symptom was caused by brain metastasis. Such cases are extremely rare. The mass was presurgically diagnosed as a cavernous angioma but was actually a case of brain metastasis. If we had not performed mass removal, we would not have been able to diagnose it as brain metastasis from thyroid papillary carcinoma and would have not taken appropriate steps toward further examinations and treatment. We must manage carefully a mass resembling cavemous angioma in MRI in consideration of the possibility of its being another diseases such as a metastatic tumor.

Bortezomib-induced enzyme-targeted radiation therapy in herpesvirus-associated tumors.

We investigated the possibility of using a pharmacologic agent to modulate viral gene expression to target radiotherapy to tumor tissue. In a mouse xenograft model, we had previously shown targeting of [(125)I]2'-fluoro-2'-deoxy-beta-D-5-iodouracil-arabinofuranoside ([(125)I]FIAU) to tumors engineered to express the Epstein-Barr virus thymidine kinase (EBV-TK). Here we extend those results to targeting of a therapeutic radiopharmaceutical [(131)I]FIAU to slow or stop tumor growth or to achieve tumor regression. These outcomes were achieved in xenografts with tumors that constitutively expressed the EBV-TK. With naturally infected EBV tumor cell lines (Burkitt's lymphoma and gastric carcinoma), activation of viral gene expression by pretreatment with bortezomib was required. Marked changes in tumor growth could also be achieved in naturally infected Kaposi's sarcoma herpesvirus tumors after pretreatment with bortezomib. Bortezomib-induced enzyme-targeted radiation therapy illustrates the possibility of pharmacologically modulating tumor gene expression to result in targeted radiotherapy.

Virus-associated tumor imaging by induction of viral gene expression.

PURPOSE: EBV and other herpesviruses are associated with a variety of malignancies. The EBV thymidine kinase (TK) is either not expressed or is expressed at very low levels in EBV-associated tumors. However, EBV-TK expression can be induced in vitro with several chemotherapeutic agents that promote viral lytic induction. The goal of this study is to image EBV-associated tumors by induction of viral TK expression with radiolabeled 2'-fluoro-2'-deoxy-beta-D-5-iodouracil-arabinofuranoside (FIAU). EXPERIMENTAL DESIGN: Immunoblot, luciferase reporter assay, and in vitro assay with [(14)C]FIAU were used to show the effects of bortezomib on the induction of lytic gene expression of EBV-associated tumor cells. In vivo imaging and ex vivo biodistribution studies with [(125)I]FIAU on EBV-associated tumors were done to visualize and confirm, respectively, the EBV(+) tumor-specific effects of bortezomib. RESULTS: In vitro assays with [(14)C]FIAU and ex vivo biodistribution studies with [(125)I]FIAU showed that uptake and retention of radiolabeled FIAU was specific for cells that express EBV-TK. Planar gamma imaging of EBV(+) Burkitt's lymphoma xenografts in severe combined immunodeficient mice showed [(125)I]FIAU localization within tumors following treatment with bortezomib. CONCLUSIONS: These results indicate the feasibility of imaging chemotherapy-mediated viral lytic induction by radiopharmaceutical-based techniques such as single photon emission computed tomography and positron emission tomography.

p73 gene promoter methylation in Epstein-Barr virus-associated gastric carcinoma.

To clarify the significance of p73 in Epstein-Barr virus (EBV)-associated gastric carcinoma (GC), the immunohistochemical expression and CpG-island methylation of p73 were evaluated in cancer tissues and adjacent nonneoplastic tissues of GC with and without EBV infection. Loss of p73 expression by immunohistochemistry was specific to EBV-associated GC (11/13) compared to EBV-negative GC (3/38), which was independent of abnormal p53 expression. With methylation-specific polymerase chain reaction (MSP), the aberrant methylation of p73 exon 1 was similarly specific to EBV-associated GC (12/13), and also rare in EBV-negative GC (2/38). Bisulfite sequencing for p73 exon 1 and its 5' region confirmed the MSP results, showing uniform and high-density methylation in EBV-associated GC. Comparative MSP analysis of p14, p16 and p73 methylation, using 20 cases each of formalin-fixed and paraffin-embedded tissues of early GC with and without EBV infection, confirmed 2 types of methylation: global methylation with increased rates (p14 and p16) and specific methylation of p73 in EBV-associated GC. In nonneoplastic mucosa, p14, p16 and p73 methylation occurred in both EBV-associated (8/33, 6/34 and 3/38, respectively) and EBV-negative GC (6/23, 4/35, and 1/35). p73 methylation was observed in the mucosa without H. pylori infection in all 4 samples. Loss of p73 expression through aberrant methylation of the p73 promoter occurs specifically in EBV-associated GC, together with the global methylation of p14 and p16. A specific type of gastritis, prone to a higher grade of atrophy and p73 methylation, may facilitate the development of EBV-associated GC.

Phenotype analysis by MUC2, MUC5AC, MUC6, and CD10 expression in Epstein-Barr virus-associated gastric carcinoma.

BACKGROUND: Gastric marker mucins (MUC5AC and MUC6) and intestinal marker molecules (MUC2 and CD10) have been used to determine the cell lineage of epithelial cell of gastric carcinoma (GC). METHODS: To clarify the characteristics of Epstein-Barr virus (EBV)-associated GC, 18 cases were immunohistochemically evaluated along with 56 cases of EBV-negative GC. RESULTS: MUC2 expression was lower in EBV-associated GC: immunostaining grades 0, 1, 2, 3, and 4 were observed in 10, 6, 1, 1, and 0 cases of EBV-associated GC, respectively, and in 18, 11, 15, 6, and 6 cases of EBV-negative GC, respectively (P = 0.013). CD10 positivity (grades 2-4) in EBV-associated GC was 6%, significantly lower than in EBV-negative GC (34%) (P = 0.030). When phenotypes of GC were categorized by the combined positivities of gastric markers (either MUC5AC or MUC6) and intestinal markers (either MUC2 or CD10), EBV-associated GC included primarily null (44%) and gastric (39%) types, but EBV-negative GC comprised null (7%), gastric (30%), intestinal (27%), and mixed (36%) types. The age of patients with gastric types was significantly younger for both EBV-associated GC and EBV-negative GC cases. CONCLUSIONS: Neoplastic epithelial cells of EBV-associated GC did not express MUC2 or CD10, and most of them were categorized as null or gastric types. EBV infection may occur in the epithelial cells of null or gastric phenotypes, which may be devoid of transdifferentiation potential toward intestinal phenotypes.