Diagnostic accuracy of frozen section biopsy for early gastric cancer extent during endoscopic submucosal dissection: a prospective study.

BACKGROUND: Accurate diagnosis of the lateral extent of early gastric cancer during endoscopic submucosal dissection (ESD) is crucial to achieve negative resection margins. Similar to intraoperative consultation with a frozen section in surgery, rapid frozen section diagnosis with endoscopic forceps biopsy may be useful in assessing tumor margins during ESD. This study aimed to evaluate the diagnostic accuracy of frozen section biopsy. METHODS: We prospectively enrolled 32 patients undergoing ESD for early gastric cancer. Biopsy samples for the frozen sections were randomly collected from fresh resected ESD specimens before formalin fixation. Two different pathologists independently diagnosed 130 frozen sections as "neoplasia," "negative for neoplasia," or "indefinite for neoplasia," and the frozen section diagnosis was compared with the final pathological results of the ESD specimens. RESULTS: Among the 130 frozen sections, 35 were from cancerous areas, and 95 were from non-cancerous areas. The diagnostic accuracies of the frozen section biopsies by the two pathologists were 98.5 and 94.6%, respectively. Cohen's kappa coefficient of diagnoses by the two pathologists was 0.851 (95% confidence interval: 0.837-0.864). Incorrect diagnoses resulted from freezing artifacts, a small volume of tissue, inflammation, the presence of well-differentiated adenocarcinoma with mild nuclear atypia, and/or tissue damage during ESD. CONCLUSIONS: Pathological diagnosis of frozen section biopsy is reliable and can be applied as a rapid frozen section diagnosis for evaluating the lateral margins of early gastric cancer during ESD.

Dasatinib-induced colitis: clinical, endoscopic and histological findings.

BACKGROUND: Dasatinib, a second-generation tyrosine kinase inhibitor, is widely used in patients with haematological malignancies. The main side effects of dasatinib are myelosuppression and pleural effusion; however, colitis, such as haemorrhagic colitis and cytomegalovirus (CMV) colitis, have been reported as rare side effects. There are only a few studies conducted on dasatinib-induced colitis. AIMS: This study aimed to clarify the clinical, endoscopic and pathological features of dasatinib-induced colitis. METHODS: This retrospective study included 51 consecutive patients who received dasatinib therapy between June 2009 and July 2020. Dasatinib-induced colitis was defined as the presence of colitis symptoms, exclusion of other diseases that could cause colitis, and improvement in symptoms after dasatinib withdrawal or dose reduction. CMV positivity was determined based on the positive result of CMV immunostaining. RESULTS: Dasatinib-induced colitis was diagnosed in nine of 51 patients (17.6%), and most of the symptoms were mild diarrhoea and bloody stools. The endoscopic findings were characterised by loss of vascular pattern (100%) and multiple small erosions (83.3%) which were mainly found in the transverse and descending colon. In a patient who underwent follow-up colonoscopy once a year while taking dasatinib, endoscopic findings changed from initial erythematous spots to multiple erosions, and finally to multiple small round elevations with erosion on the top that disappeared after discontinuation of dasatinib. Anti-CMV therapy was administered to one patient, but the treatment failed. All patients with dasatinib-induced colitis were cured after the discontinuation of dasatinib. CONCLUSION: Physicians should consider CMV reactivation to manage dasatinib-induced colitis.

Endoscopic-assisted resection of pleomorphic adenoma in the accessory parotid gland.

Background : An accessory parotid gland (APG) is a common anatomical structure that occurs in 10%-56% of individuals. Pleomorphic adenomas are the most common benign tumors of the APG, and their ideal treatment is surgical excision, although there is a risk for aesthetic disorders and facial nerve damage due to the site of origin. Moreover, despite being benign, these tumors are known to recur. Therefore, it is necessary to achieve both reliable excision and avoidance of facial nerve damage. Case presentation : We report a case of a 49-year-old Japanese man with a mass in his left cheek. The lesion was diagnosed as a benign salivary gland tumor derived from the APG by computed tomography imaging, magnetic resonance imaging and fine needle aspiration cytology. We resected the tumor using modified high submandibular incision under the endoscopic-assisted field of view. Discussion and Conclusions : The tumor was less invasive and reliably resected using an endoscope. In surgical treatment, the endoscopic-assisted technique is very useful to achieve complete tumor resection and prevent relapse while avoiding serious complications due to surgical procedures. J. Med. Invest. 68 : 376-380, August, 2021.

Anti-proteinase 3 antineutrophil cytoplasmic antibody reflects disease activity and predicts the response to steroid therapy in ulcerative colitis.

BACKGROUND: Serum anti-proteinase 3 antineutrophil cytoplasmic antibody (PR3-ANCA) is a disease-specific antibody against granulomatosis with polyangiitis. PR3-ANCA is a useful serological marker for disease severity in ulcerative colitis (UC). The purpose of this study was to investigate whether PR3-ANCA levels could also predict the success of induction therapy and to compare its performance against other markers, including serum CRP and fecal hemoglobin. METHODS: This was a multicenter retrospective study. In total, 159 patients with active-phase UC underwent colonoscopy. Disease activity was measured using the Mayo endoscopic subscore (MES). PR3-ANCA positivity and the response to induction therapy, either 5-aminosalicylic acid or steroid, were assessed. PR3-ANCA, CRP, and fecal hemoglobin were measured during the active phase, and during clinical remission. RESULTS: Eighty-five (53.5%) of 159 patients with active UC were positive for PR3-ANCA. PR3-ANCA titers were significantly higher in the group of patients with MES 3 compared to patients with MES 1 (P = 0.002) or MES 2 (P = 0.035). Steroid therapy was administered to 56 patients with a median partial Mayo score of 7 (5-9), which is equivalent to moderate-to-severe disease activity. PR3-ANCA positivity of non-responders to steroid therapy was significantly higher than that of responders (71.9% vs, 41.7%, P = 0.030), whereas CRP and fecal hemoglobin were not predictive of steroid response. Multivariate analysis demonstrated that PR3-ANCA positivity was associated with non-response to steroid therapy (odds ratio 5.19; 95% confidence interval, 1.54-17.5; P = 0.008). Of the 37 patients treated to clinical remission who were also positive for PR3-ANCA during the active phase, 27 had an MES of ≥ 1, and 10 patients had an MES of 0. In clinical remission, the proportion of patients with MES 0 in 17 patients whose PR3-ANCA became negative was significantly higher than that in 20 patients whose PR3-ANCA remained positive (47.1% vs. 10.0%, P = 0.023). CONCLUSIONS: PR3-ANCA not only serves as a marker of disease activity, but also predicts the failure of steroid therapy in moderate-to-severe UC. TRIAL REGISTRATION: This study was retrospectively registered in the UMIN Clinical Trials Registry System (000039174) on January 16, 2020.

Clinicopathological examination of ESD as salvage therapy for esophageal cancer after definitive chemo-radiation therapy.

BACKGROUND AND STUDY AIMS: Salvage therapy for esophageal cancer following chemo-radiation therapy (CRT) has not been established. We aimed to evaluate endoscopic submucosal dissection (ESD) as a salvage therapy based on histopathological features of lesions. PATIENTS AND METHODS: We compared 10 lesions in eight patients with local residual, recurrent, or metachronous esophageal squamous cell carcinoma treated by ESD after CRT (CRT group) and 59 lesions treated by ESD without CRT (non-CRT group) during the same period. RESULTS: The en bloc resection rate was 100 % while the complete resection rate was 80.0 % in the lesions after CRT, indicating no difference between the CRT and non-CRT groups. Pathological examination showed that fibrosis was more intense in the lamina propria mucosa, muscularis mucosa, and submucosa. The muscularis mucosa was thicker in both non-tumor and tumor sites in the CRT group compared to the non-CRT group. However, severe submucosal fibrosis was observed only in one lesion in the CRT group. The maximum diameter of the submucosal artery was significantly larger in the CRT group ( P  < 0.001). CONCLUSIONS: Compared to the non-CRT group, the lesions in the CRT group were accompanied by fibrosis while the muscularis mucosa were thicker; however, severe fibrosis of the submucosa was rare. It is important to dissect the muscularis mucosa appropriately during ESD, which makes successful dissection of the submucosa possible. Attention should be paid to bleeding from large arteries.

A20 (TNFAIP3) Alterations in Primary Intestinal Diffuse Large B-cell Lymphoma.

The gastrointestinal (GI) tract is the most frequently involved site of extranodal non-Hodgkin lymphomas, and diffuse large B-cell lymphoma (DLBCL) is the most common subtype occurring in the GI tract. TNFAIP3 (A20) genetic alterations were reported to be involved in DLBCL's pathogenesis and a portion of GI-DLBCL cases harbor this alteration. However, the frequency and clinicopathological relations focusing on small and large intestinal DLBCL are unclear. Here, we examined A20 deletion and protein expression and analyzed the clinicopathological features of 52 cases of primary intestinal DLBCL. The most frequently involved site was the ileocecal region (75%), followed by small bowel (13.5%) and large intestine. Immunohistochemically, the ileocecal cases expressed BCL6 (p=0.027) and MUM1 (p=0.0001) significantly more frequently than the small intestinal cases. Six of 47 cases (13%) had A20 heterozygous deletion, whereas all 6 heterozygously deleted cases had detectable A20 protein expression. In summary, A20 abnormality was less prevalent among intestinal DLBCLs with some discordancy between gene deletion and protein expression. Although the A20 alteration status did not affect any clinicopathological characteristics in this series, further studies exploring alterations of A20 and other NF-κB components in primary intestinal DLBCL are needed.

A Case of Spontaneous Tumor Lysis Syndrome in a Patient with Ovarian Cancer.

Tumor lysis syndrome (TLS) is a potentially life-threating complication of tumors or chemotherapy treatment. TLS commonly occurs in hematological malignancies, but it is very rare in patients with a solid tumor. In cases of solid tumors, TLS usually occurs spontaneously and after the initiation of anticancer therapy, and it has a high mortality rate. We present the novel case of a 62-year-old woman with an ovarian tumor who spontaneously developed TLS. Surgical reduction of the tumor mass vastly improved her condition. She showed no sign of tumor recurrence 8 months after treatment. As TLS is life-threatening, successful treatments must be seriously considered.

Immunohistochemical characterization of renal tumors in patients with Birt-Hogg-Dubé syndrome.

Birt-Hogg-Dubé syndrome (BHD) is an autosomal dominant disorder associated with a germline mutation of folliculin (FLCN). The affected families are at a high risk for developing multiple renal cell carcinomas (RCC). Little is known about the immunostaining patterns of mutant FLCN-associated RCCs. We investigated 32 RCCs obtained from 17 BHD patients. The studied tumors included chromophobe RCCs (n = 15), hybrid oncocytic/chromophobe tumors (HOCT) (n = 14) and clear cell RCCs (n = 3). Almost all chromophobe RCCs and HOCTs revealed positive staining for S100A1, Ksp-cadherin and CD82. They stained either focally or diffusely for CK7, and were negative for CA-IX. All clear cell RCCs were positively stained for CA-IX and negative for CK7. These data confirmed that mutant FLCN-associated oncocytic and clear cell RCCs exhibited generally similar immunostaining patterns compared to their sporadic counterparts. Frequent positive staining for S100A1, Ksp-cadherin and CD82 in chromophobe RCCs and HOCTs indicated that these two types were relatively similar rather than distinctively different in their patterns of immunoreactivity. Characteristic peri-nuclear halos and polygonal cells with clear cytoplasm, which often misleads pathologists into the diagnosis of clear cell RCC, should be carefully examined using an immunohistochemical panel including CA-IX, Ksp-cadherin, CD82 and CK7.

Duodenal follicular lymphoma: comprehensive gene expression analysis with insights into pathogenesis.

Follicular lymphoma (FL) of the gastrointestinal tract, particularly duodenal follicular lymphoma (DFL), is a rare variant of FL with indolent clinical behavior, and this disease is included in the 2008 World Health Organization classification system. In contrast to nodal follicular lymphoma (NFL), DFL occurs most frequently in the second part of the duodenum, lacks follicular dendritic cell meshworks and has memory B-cell characteristics. However, its molecular pathogenesis is still unclear. In the present study, we examined 10 DFL, 18 NFL and 10 gastric MALT lymphoma samples using gene expression analysis. Quantitative RT-PCR experiments and immunohistochemical analysis for 72 formalin-fixed, paraffin-embedded tissues from an independent series, including 32 DFL, 19 gastric MALT lymphoma and 27 NFL samples, were performed for validation of microarray data. Gene expression profiles of the three lymphoma types were compared using 2918 differentially expressed genes (DEG) and results suggested that DFL shares characteristics of MALT lymphoma. Among these DEG, CCL20 and MAdCAM-1 were upregulated in DFL and MALT but downregulated in NFL. In contrast, protocadherin gamma subfamily genes were upregulated in DFL and NFL. Quantitative RT-PCR and immunohistochemical studies demonstrated concordant results. Double immunofluorescence studies revealed that CCL20 and CCR6 were co-expressed in both DFL and MALT. We hypothesize that increased expression of CCL20 and MAdCAM-1 and co-expression of CCL20 and CCR6 may play an important role in tumorigenesis.

IgG4-related disease involving the sclera.

A 49-year-old female patient previously treated for scleritis and uveitis-induced cataract in the right eye presented with a subretinal white lesion in the same eye. With a preliminary diagnosis of choroidal tumor, enucleation of the eyeball was performed in accordance with the patient's request. Histologic and immunohistologic examinations were consistent with immunoglobulin G4-related disease. The case demonstrates that it is important to consider IgG4-related disease in the differential diagnosis of an intraocular tumor.

Distinct morphologic, phenotypic, and clinical-course characteristics of indolent peripheral T-cell lymphoma.

Peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) consists of a heterogeneous group of lymphomas. Patients generally show an aggressive clinical course and very poor outcome. Although the 2008 World Health Organization classification of PTCL-NOS includes 3 variants, low-grade lymphoma is not included. Of 277 PTCL-NOS cases recorded in our consultation files, we examined the clinicopathologic characteristics of 10 patients with T-cell lymphomas composed of small-sized cells with slight nuclear atypia. Eight patients showed extranodal involvement (5 patients, spleen; 3 patients, thyroid), and 5 patients were at clinical stage I or II. Histologically, all samples presented diffuse infiltrate of small lymphoid cells, with few mitotic figures. Immunohistologically, all samples were positive for CD3, and CD20 was detected in 5 samples. All samples showed a low Ki-67 labeling index (mean, 1.05%), and 7 samples were positive for central memory T-cell markers. Clonal T-cell receptor γ chain and/or α-ß chain gene rearrangements were detected in all 10 patients. Five patients received chemotherapy, whereas for 3 patients, treatment consisted only of observation following surgical resection of the spleen or thyroid. Nine patients were alive at a median follow-up time of 19.5 months, whereas 1 patient died of an unrelated disease. The present study strongly indicates that T-cell lymphoma with small-sized lymphoma cells and a low Ki-67 labeling index is a distinct variant. Recognition of this novel lymphoma subtype, which should not be defined merely as PTCL-NOS, should be seriously considered.

A20 (TNFAIP3) deletion in Epstein-Barr virus-associated lymphoproliferative disorders/lymphomas.

A negative regulator of the nuclear factor (NF)-κB pathway, A20 (TNFAIP3), is inactivated in several types of lymphomas; particularly in diffuse large B-cell lymphoma (DLBCL), classical Hodgkin's lymphoma, and extranodal marginal zone lymphoma of the mucosa-associated lymphoid tissue. These findings suggest that the NF-κB activation is related to A20 inactivation. Recently, A20 inactivation has also been observed in Epstein-Barr virus (EBV)-related lymphomas; however, this occurrence has not been well investigated. Moreover, NF-κB is a key molecule in activated B-cell-like (ABC)-type DLBCL; EBV-associated DLBCL is of the ABC type. Therefore, we focused on A20 deletions in EBV-associated lymphoproliferative disorders/lymphomas. Using fluorescent in situ hybridization analysis, A20 deletions were identified in 4 of 13 samples from patients with pyothorax-associated lymphoma (PAL) (31%), 3 of 20 samples from nasal-type NK/T cell lymphomas (NKTLs) (15%), 1 of 8 samples of EBV-positive DLBCL of the elderly (DLBCL-e) (13%), but not in any of the 11 samples from individuals with methotrexate-related lymphoproliferative disorder (MTX-LPD) (0%). Among the samples with A20 deletions, EBV latent membrane protein 1 (LMP-1) expression was detected in all 4 of the PAL samples with A20 deletions and in the DLBCL-e sample with an A20 deletion, but not in any of the 3 NKTL samples. This finding indicated that A20 deletions were not directly related to the EBV latency pattern of lymphomas, although such deletions might be related to the diagnostic category. Immunohistologically, the A20 protein was absent in 2 (15%) of the 13 PAL samples, 1 (9%) of 11 MTX-LPD samples, and in none of the 20 NKTL (0%) or 8 DLBCL-e samples. In conclusion, A20 deletion and/or dysfunctional expression are frequently associated with PALs, and A20 abnormalities may be related to the pathogenesis of PAL.

Strong anti-tumor effect of NVP-AUY922, a novel Hsp90 inhibitor, on non-small cell lung cancer.

The anti-tumor activity of a newly developed Hsp90 inhibitor, NVP-AUY922 (AUY922), against non-small cell lung cancer (NSCLC) was examined. Twenty-one NSCLC cell lines were used, the somatic alterations of which were characterized. Cell proliferation was analyzed using a modified MTS assay. Expression of the client proteins was assessed using Western blotting. The cell cycle was analyzed using flow cytometry. The IC50 value of AUY922 for the NSCLC cell lines ranged from 5.2 to 860 nM (median, 20.4 nM). Based on previous data, cells with an IC50 of less than 50 nM were classified as sensitive cells and 19 of the 21 NSCLC cell lines were judged to be sensitive. The IC50 of five malignant pleural mesothelioma (MPM) cell lines revealed that the MPM cells had a significantly higher IC50 value (median, 89.2 nM; range, 22.2-24,100 nM) than the NSCLC cells (p=0.015). There was significant depletion of both the total and phosphorylated client proteins--EGFR, MET, HER2 and AKT--at low drug concentrations (50-100 nM) in drug-sensitive cell lines. Cell-cycle analysis was performed for two sensitive cell lines, H1975 and H838. Following AUY922 treatment, an increase in the sub-G0-G1 cell population, as well as appearance of cleaved PARP expression, indicated the induction of apoptosis. In conclusion, AUY922 was effective against most NSCLC cell lines, independent of the type of known molecular alteration, and appears to be a promising new drug for the treatment of NSCLC.

The anti-proliferative effect of heat shock protein 90 inhibitor, 17-DMAG, on non-small-cell lung cancers being resistant to EGFR tyrosine kinase inhibitor.

Acquired resistance to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), gefitinib and erlotinib, is frequently observed after initiation of TKIs therapy. Non-small-cell lung cancers (NSCLC) with activating EGFR mutations were reported to be sensitive to heat shock protein 90 (Hsp90) inhibitors regardless of the secondary TKI-resistant T790M mutation. We established EGFR-TKI resistant clones for PC-9 cell lines, harboring EGFR exon 19 deletions, with or without the secondary T790M mutation. We examined the anti-proliferative effect of 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG), an orally active Hsp90 inhibitor, on the growth of NSCLC cell lines in vitro and in vivo. In MTS assay, the IC(50) values of 17-DMAG for 13 EGFR-mutant cell lines including eight EGFR-TKI resistant cell lines ranged from 0.04 to 0.16 µM while those for seven EGFR-wild type cell lines ranged from 1.6 to 27.4 µM. Western blot analysis revealed that phospho-EGFR, phospho-Akt, phospho-MAPK, cdk4, and cyclin D1 were more readily depleted by 17-DMAG treatment in EGFR-mutant cell lines than in EGFR-wild type cell lines. Cleaved PARP expression confirmed apoptosis in response to 17-DMAG treatment in EGFR-mutant cell lines but not in EGFR-wild type cell lines. In mice xenograft models, 17-DMAG significantly reduced the growth of EGFR-mutant lines irrespective of T790M mutation. These results suggested that 17-DMAG is a potential novel therapeutic agent for NSCLC patients with EGFR mutations with or without EGFR-TKI resistance.

Aberrant methylation of p21 gene in lung cancer and malignant pleural mesothelioma.

Suppression of p21 has been implicated in the genesis and progression of many human malignancies. DNA methylation is an important mechanism of gene silencing in human malignancies. In this study, we examined the expression status and aberrant methylaion of p21 in lung cancers and malignant pleural mesotheliomas (MPM). We used 12 small cell lung cancer (SCLC) cell lines, 13 non-small cell lung cancer (NSCLC) cell lines, 50 primary NSCLCs, 6 MPM cell lines and 10 primary MPMs. The expression and methylation of p21 was examined by reverse transcription-PCR (RT-PCR), Western blotting and methylation-specific PCR (MSP) assay. Loss of p21 protein expression was observed in 7 SCLC cell lines (58.3%), 5 NSCLC cell lines (38.5%) and 3 MPM cell lines (50%) while mRNA expression was lost in 2 SCLC cell lines (16.7%), 2 NSCLC cell lines (15.4%) and none of the MPM cell lines. Aberrant methylation of p21 was found in 8.3% of SCLC cell lines, 30.2% of NSCLCs and 6.3% of MPMs. Among primary NSCLCs, methylation in adenocarcinomas was significantly more frequent than in squamous cell carcinomas. Loss of p21 expression was frequently observed in lung cancers and MPMs and aberrant methylation was one of the mechanisms of suppression of p21, especially in NSCLCs.