A case of non-Hodgkin lymphoma of the upper gingiva with minimal residual disease detected in cryopreserved ovarian tissue: A case report

Recently, more than 200 live births following ovarian tissue cryopreservation (OTC) and transplantation in cancer survivors have been reported worldwide. However, cancer survivors with minimal residual disease (MRD) in cryopreserved ovarian tissue are at the risk of relapse through the graft. Here, we report a rare case of a 19-year-old female patient with non-Hodgkin lymphoma who had MRD in the ovary harvested for OTC. The patient was diagnosed with aggressive B-cell lymphoma after gingival biopsy. The 18F-fluoro-2-deoxy-D-glucose positron emission tomography scan performed before OTC showed no viable lesions in either ovary. However, on histological evaluation, we detected infiltration of lymphoma cells in the ovary. Informed consent about MRD is required even if there is no evidence of MRD in the ovary before OTC. Patients whose cryopreserved ovaries have MRD may require the development of alternative assisted reproductive technologies such as in vitro growth or artificial ovary.

Clinical Significance of Early Venous Filling Detected via Preoperative Angiography in Glioblastoma

Preoperative angiography in glioblastoma (GBM) often shows arteriovenous shunts and early venous filling (EVF). Here, we investigated the clinical implications of EVF in GBM as a prognostic and vascular mimicry biomarker. In this retrospective multicenter study, we consecutively enrolled patients who underwent angiography with a GBM diagnosis between 1 April 2013 and 31 March 2021. The primary and secondary endpoints were the differences in overall survival (OS) and progression-free survival (PFS), respectively, between cases with and without EVF. Of the 133 initially enrolled patients, 91 newly diagnosed with GBM underwent preoperative angiography and became the study population. The 6-year OS and PFS were significantly worse in the EVF than in the non-EVF group. Moreover, 20 GBM cases (10 with EVF and 10 without EVF) were randomly selected and evaluated for histological vascular mimicry. Except for two cases that were difficult to evaluate, the EVF group had a significantly higher frequency of vascular mimicry than the non-EVF group (0/8 vs. 5/10, p = 0.04). EVF on preoperative angiography is a robust prognostic biomarker for GBM and may help detect cases with a high frequency of histological vascular mimicry.

T‐cell lymphoma, B‐cell lymphoma, and myelodysplastic syndrome harboring common mutations: Trilineage tumorigenesis from a common founder clone

A 64‐year‐old man with angioimmunoblastic T‐cell lymphoma (AITL) subsequently developed diffuse large B‐cell lymphoma (DLBCL) and myelodysplastic syndrome (MDS). Genomic profiling of AITL, DLBCL, and MDS samples revealed that the tumor cells from all samples shared common mutations in TET2 and DNMT3A. In addition, the IDH2 mutation was observed in AITL, and TP53 mutation was observed in DLBCL and MDS. These findings illustrate the clonal relationship between AITL and DLBCL in addition to AITL and MDS, with the latter being increasingly reported. The present findings strongly support the theory of multistep and multilineage tumorigenesis from a common founder clone.

Severe acute heart failure during or following cytokine release syndrome after CAR T-cell therapy

Although cardiac dysfunction after chimeric antigen receptor (CAR) T-cell therapy has been increasingly reported, the underlying dynamics and pathogenesis are not well documented. Herein, we describe the clinical presentation and treatment for two patients who developed severe acute heart failure after CAR T-cell therapy. Both cases shared several common characteristics, including the bone marrow involvement at the time of CAR T-cell therapy and early onset of cytokine release syndrome (CRS) with fever developing on the day of CAR T-cell infusion. Patients with early onset and/or severe CRS should be carefully monitored for the possibility of heart failure.

[A Case of Curative Resection for Borderline-Resectable Locally Advanced Rectal Cancer Treated with Preoperative Chemoradiotherapy followed by Extended Surgery]

A 55-year-old man was referred for surgery after colonoscopy revealed type 3 advanced lower rectal cancer in the lower rectum. CT and MRI scan showed no distant metastasis but on the left side of the rectum, there was a 34×30 mm large mass suspicious of lymph node metastasis, which had left-sided wall pelvic fascia invasion. We performed preoperative chemoradiotherapy(CRT)to ensure a secure surgical margin. As a result, the tumor volume was reduced and robot-assisted rectal amputation and bilateral lateral lymph node dissection were performed using a combined transperineal speculum approach. The pathological results showed that circumferential resection margin of 3 mm was secured. The lymph nodes on the left side of the rectum were mostly fibrotic and the tumor component had almost disappeared. Preoperative CRT is useful for securing the surgical margin. The multidisciplinary treatment including extended surgery enabled the curative resection of even highly advanced rectal cancer.

Surface-state Coulomb repulsion accelerates a metal-insulator transition in topological semimetal nanofilms

The emergence of quantization at the nanoscale, the quantum size effect (QSE), allows flexible control of matter and is a rich source of advanced functionalities. A QSE-induced transition into an insulating phase in semimetallic nanofilms was predicted for bismuth a half-century ago and has regained new interest with regard to its surface states exhibiting nontrivial electronic topology. Here, we reveal an unexpected mechanism of the transition by high-resolution angle-resolved photoelectron spectroscopy combined with theoretical calculations. Anomalous evolution and degeneracy of quantized energy levels indicate that increased Coulomb repulsion from the surface states deforms a quantum confinement potential with decreasing thickness. The potential deformation strongly modulates spatial distributions of quantized wave functions, which leads to acceleration of the transition beyond the original QSE picture. This discovery establishes a complete picture of the long-discussed transition and highlights a new class of size effects dominating nanoscale transport in systems with metallic surface states.

Hypermethylation of Corticotropin Releasing Hormone Receptor-2 Gene in Ulcerative Colitis Associated Colorectal Cancer

BACKGROUND/AIM

The difficulty of early diagnosis of colitis associated colorectal cancer (CACRC) due to colonic mucosal changes in long-standing ulcerative colitis (UC) patients is often experienced in daily clinical practice. Noninvasive objective monitoring for cancer development is advantageous for optimizing treatment strategies in UC patients. We aimed to examine the epigenetic alterations occurring in CACRC, focusing on DNA hypermethylation of CpG islands.

MATERIALS AND METHODS

The level of DNA methylation in CpG cites was compared between CACRC and the counterpart non-tumorous mucosa using Infinium HumanMethylation 450K BeadChip.

RESULTS

Our subjects included 3 males and 3 females (median age, 49.5 years). The 450K CpG site DNA methylation microarray revealed that the difference in β value (level of hypermethylation) was the highest for corcicotropin releasing hormone receptor 2 (CRHR2) between CACRC and counterpart non-tumorous mucosa.

CONCLUSION

Detection of hypermethylation of CRHR2 may be promising for cancer screening in UC patients.

Determination of Total Dietary Fiber in Selected Foods Containing Resistant Maltodextrin by Enzymatic-Gravimetric Method and Liquid Chromatography: Collaborative Study

A method was developed for determination of total dietary fiber (TDF) in foods containing resistant maltodextrin (RMD) which includes nondigestible carbohydrates that are not fully recovered as dietary fiber by conventional TDF methods such as AOAC 985.29 or 991.43. Because the average molecular weight (MW) of RMD is 2000 daltons, lower MW soluble dietary fiber components do not precipitate in 78% ethanol; therefore, RMD is not completely quantitated as dietary fiber by current AOAC methods. The accuracy and precision of the method was evaluated through an AOAC collaborative study. Ten laboratories participated and assayed 12 test portions (6 blind duplicates) containing RMD. The 6 test pairs ranged from 1.5 to 100% RMD. The method consisted of the following steps: (1) The insoluble dietary fiber (IDF) and high MW soluble dietary fiber (HMWSDF) were determined by AOAC 985.29. (2) Ion exchange resins were used to remove salts and proteins contained in the AOAC 985.29 filtrates (including ethanol and acetone). (3) The amount of low MWRMD (LMWRMD) in the filtrates were determined by liquid chromatography. (4) The TDF was calculated by summation of the IDF, HMWSDF, and LMWRMD fractions having nondigestible carbohydrates with a degree of polymerization of 3 and higher. Repeatability standard deviations (RSDr) were 1.33–7.46%, calculated by including outliers, and 1.33–6.10%, calculated by not including outliers. Reproducibility standard deviations (RSDR) were 2.48–9.39%, calculated by including outliers, and 1.79–9.39%, calculated by not including outliers. This method is recommended for adoption as Official First Action.

Expression of p16 in nodular fasciitis: an implication for self-limited and inflammatory nature of the lesion

Nodular fasciitis (NF) is a self-limited tumorous lesion occurring in the upper as well as lower extremities. NF is composed of a proliferation of "primary culture"-like myofibroblastic cells with nuclear atypia and large nucleoli, thus mimicking sarcoma. NF harbors a promoter-swapping fusion gene containing the entire coding region of USP6 gene. Therefore, NF is a tumor with a fusion oncogene but self-limited. In order to explore why NF is self-limited, we examined whether myofibroblastic cells in NF express p16 protein, a gene product of CDKN2A gene and an inhibitor of cyclin-dependent kinase 4 (CDK4) as well as one of the hallmarks of cellular senescence. We immunohistochemically demonstrated strong and diffuse expression of p16 in myofibroblastic cells in 11 out of 15 cases of NF, and strong but partial expression in the remaining 4 of the cases. We also showed that 15 out of 15 cases of NF were immunohistochemically negative or only showed focal and faint immunopositivity for CDK4, murine double minute 2 (MDM2), and TP53 proteins. Furthermore, there were no significant changes in the copy number of CDKN2A, CDK4 and MDM2 genes, and no significant mutations in TP53, RB1, and CDKN2A genes in 1 case of NF selected. These data suggest a possible involvement in cell cycle arrest and presumed cellular senescence by p16 in myofibroblastic cells in NF. This may explain the self-limited as well as inflammatory nature of NF as a senescence-associated secretory phenotype.

The eCura system as a novel indicator for the necessity of salvage surgery after non-curative ESD for gastric cancer: A case-control study

Endoscopic submucosal dissection (ESD) for early gastric cancer does not always lead to complete cancer resection. The aim of this study was to determine indicators for cancer residue (CR) status in cases of non-curative ESD. We analyzed 47 cases of non-curative ESD followed by salvage surgery and collected data regarding the rates of CR, which included both local CR and lymph node metastasis (LNM). To elucidate the risk factors for CR status, we compared the CR positive and the CR negative groups among surgical specimens according to the following variables obtained from ESD findings: tumor location, tumor size, depth of invasion, lympho-vascular invasion, histological margin, and histological diagnosis. The eCura system, which is an LNM risk scoring system, was also applied and scores were calculated in each case as follows: 3 points for lymphatic invasion and 1 point each for tumor size >30 mm, positive vertical margin, venous invasion, and submucosal invasion ≥500 μm. There were 9 (19%) CR positive cases, which included 6 cases of local CR and 4 cases of LNM; no cancer was detected in over 80% of the patients. The eCura scoring system was the only significant factor for CR status: the higher the eCura score, the greater the CR positivity (p = 0.0128). In particular, all patients in the low-risk group (score = 0-1 point) had no CR. Although no cancer recurrence was observed during a median follow-up of 4 years, 2 patients died of pneumonia. In conclusion, the eCura system might make it possible to select appropriate cases for salvage surgery.

Element Selectivity in Second-Harmonic Generation of GaFeO_{3} by a Soft-X-Ray Free-Electron Laser

Nonlinear optical frequency conversion has been challenged to move down to the extreme ultraviolet and x-ray region. However, the extremely low signals have allowed researchers to only perform transmission experiments of the gas phase or ultrathin films. Here, we report second harmonic generation (SHG) of the reflected beam of a soft x-ray free-electron laser from a solid, which is enhanced by the resonant effect. The observation revealed that the double resonance condition can be met by absorption edges for transition metal oxides in the soft x-ray range, and this suggests that the resonant SHG technique can be applicable to a wide range of materials. We discuss the possibility of element-selective SHG spectroscopy measurements in the soft x-ray range.

Genomic landscape of colitis-associated cancer indicates the impact of chronic inflammation and its stratification by mutations in the Wnt signaling

Inflammatory bowel disease (IBD) increases the risk of colorectal cancer, known as colitis-associated cancer (CAC). It is still unclear what driver mutations are caused by chronic inflammation and lead to CAC development. To get insight into this issue, we investigated somatic alterations in CAC. We performed exome sequencing of 22 fresh CACs and targeted sequencing of 43 genes on 90 archive specimens from Japanese CAC patients, of which 58 were ulcerative colitis (UC) and 32 were Crohn's disease (CD). Consistently with the previous reports, TP53 was commonly mutated (66%) whereas APC, KRAS and SMAD4 were mutated less frequently (16%, 11% and 11%, respectively). Mucinous CD-CACs in the anus, an Asian-specific subtype of CD-CAC, had less somatic mutations in our target genes. We also found that RNF43, a negative regulator of the Wnt signaling, was somatically mutated in a significant fraction of CACs (10 of 90; 11%). Two lines of evidence indicated that somatic mutations of RNF43 were related to chronic inflammation. First, somatic mutations of RNF43 were significantly associated with longer duration of IBD. Second, clinico-pathological features suggested many of the APC-mutated CACs were actually sporadic colorectal cancer whereas RNF43-mutated CACs did not have this tendency. RNA-Seq analysis showed that RNF43-mutated CACs had elevated expression of c-Myc and its target genes, suggesting that RNF43 is a bona fide driver of CAC development. This study provides evidence that somatic mutation of RNF43 is the driver genetic alteration that links chronic inflammation and cancer development in about 10% of CACs.

Abstract 1439: Genetic profiling of colitis-associated cancer indicates de novo carcinogenesis and the impact of chronic inflammation

Background: Chronic inflammation is one of the major causes of carcinogenesis. Ulcerative colitis (UC) and Crohn’s disease (CD) increase the risk of colitis-associated cancer (CAC) development, and its biological and pathological characters are also distinct. However, the genetic mechanism of how chronic inflammation leads to CACs is still unclear.

Methods: We obtained frozen tumor tissues from 21 CAC patients and performed exome or whole-genome sequencing of the matched tumor-normal samples. We enumerated recurrently mutated genes and selected 43 genes among them for target capture. We then performed targeted resequencing of 84 FFPE specimens from CAC tissues. Totally, we made genomic profiles of 105 CACs.

Results: The most frequently mutated gene was TP53, whose mutation was found in 70 of 105 samples (67%), which is more prevalent in CACs than common colorectal cancers (CRCs). Somatic mutations of APC and KRAS were less prevalent (17 and 13 samples, respectively). Genes in the Wnt signaling pathway (APC, FBXW7, TCF7L2, and RNF43) were mutated in 31 samples, whereas those in the TGFβ pathway (TGFBR2, ACVR1B, SMAD2, SMAD4, LTBP4) were mutated in 25 samples. Mutational signature of CACs shows some differences from common CRCs.

Conclusion: Our results confirmed genetic differences for cancer development between CACs and common CRCs. Frequent TP53 mutations and less frequent APC mutations are consistent with the idea of “de novo” carcinogenesis than adenoma-carcinoma sequence. The association between the mutations and clinical information are also discussed.

Citation Format: Masashi Fujita, Nagahide Matsubara, Kazuhiro Maejima, Tomoki Yamano, Ikuo Matsuda, Seiichi Hirota, Hiroki Ikeuchi, Naohiro Tomita, Hidewaki Nakagawa. Genetic profiling of colitis-associated cancer indicates de novo carcinogenesis and the impact of chronic inflammation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1439. doi:10.1158/1538-7445.AM2017-1439

Interface electronic structure at the topological insulator-ferrimagnetic insulator junction

An interface electron state at the junction between a three-dimensional topological insulator film, Bi₂Se₃, and a ferrimagnetic insulator film, Y₃Fe₅O₁₂ (YIG), was investigated by measurements of angle-resolved photoelectron spectroscopy and x-ray absorption magnetic circular dichroism. The surface state of the Bi₂Se₃ film was directly observed and localized 3d spin states of the Fe³⁺ in the YIG film were confirmed. The proximity effect is likely described in terms of the exchange interaction between the localized Fe 3d electrons in the YIG film and delocalized electrons of the surface and bulk states in the Bi₂Se₃ film.

Proving Nontrivial Topology of Pure Bismuth by Quantum Confinement

The topology of pure Bi is controversial because of its very small (∼10  meV) band gap. Here we perform high-resolution angle-resolved photoelectron spectroscopy measurements systematically on 14-202 bilayer Bi films. Using high-quality films, we succeed in observing quantized bulk bands with energy separations down to ∼10  meV. Detailed analyses on the phase shift of the confined wave functions precisely determine the surface and bulk electronic structures, which unambiguously show nontrivial topology. The present results not only prove the fundamental property of Bi but also introduce a capability of the quantum-confinement approach.

Comprehensive behavioral phenotyping of a new Semaphorin 3 F mutant mouse

BACKGROUND

Semaphorin 3 F (Sema3F) is a secreted type of the Semaphorin family of axon guidance molecules. Sema3F and its receptor neuropilin-2 (Npn-2) are expressed in a mutually exclusive manner in the embryonic mouse brain regions including olfactory bulb, hippocampus, and cerebral cortex. Sema3F is thought to have physiological functions in the formation of neuronal circuitry and its refinement. However, functional roles of Sema3F in the brain remain to be clarified. Here, we examined behavioral effects of Sema3F deficiency through a comprehensive behavioral test battery in Sema3F knockout (KO) male mice to understand the possible functions of Sema3F in the brain.

RESULTS

Male Sema3F KO and wild-type (WT) control mice were subjected to a battery of behavioral tests, including neurological screen, rotarod, hot plate, prepulse inhibition, light/dark transition, open field, elevated plus maze, social interaction, Porsolt forced swim, tail suspension, Barnes maze, and fear conditioning tests. In the open field test, Sema3F KO mice traveled shorter distance and spent less time in the center of the field than WT controls during the early testing period. In the light/dark transition test, Sema3F KO mice also exhibited decreased distance traveled, fewer number of transitions, and longer latency to enter the light chamber compared with WT mice. In addition, Sema3F KO mice traveled shorter distance than WT mice in the elevated plus maze test, although there were no differences between genotypes in open arm entries and time spent in open arms. Similarly, Sema3F KO mice showed decreased distance traveled in the social interaction test. Sema3F KO mice displayed reduced immobility in the Porsolt forced swim test whereas there was no difference in immobility between genotypes in the tail suspension test. In the fear conditioning test, Sema3F KO mice exhibited increased freezing behavior when exposed to a conditioning context and an altered context in absence of a conditioned stimulus. In the tests for assessing motor function, pain sensitivity, startle response to an acoustic stimulus, sensorimotor gating, or spatial reference memory, there were no significant behavioral differences between Sema3F KO and WT mice.

CONCLUSIONS

These results suggest that Sema3F deficiency induces decreased locomotor activity and possibly abnormal anxiety-related behaviors and also enhances contextual memory and generalized fear in mice. Thus, our findings suggest that Sema3F plays important roles in the development of neuronal circuitry underlying the regulation of some aspects of anxiety and fear responses.

Histological diagnosis of gastric submucosal tumors: A pilot study of endoscopic ultrasonography-guided fine-needle aspiration biopsy vs mucosal cutting biopsy

AIM: To compare the usefulness of endoscopic ultrasonography-guided fine-needle aspiration biopsy (EUS-FNAB) without cytology and mucosal cutting biopsy (MCB) in the histological diagnosis of gastric submucosal tumor (SMT).

METHODS: We prospectively compared the diagnostic yield, feasibility, and safety of EUS-FNAB and those of MCB based on endoscopic submucosal dissection. The cases of 20 consecutive patients with gastric SMT ≥ 1 cm in diameter. who underwent both EUS-FNAB and MCB were investigated.

RESULTS: The histological diagnoses were gastrointestinal stromal tumors (n = 7), leiomyoma (n = 6), schwannoma (n = 2), aberrant pancreas (n = 2), and one case each of glomus tumor, metastatic hepatocellular carcinoma, and no-diagnosis. The tumors’ mean size was 23.6 mm. Histological diagnosis was made in 65.0% of the EUS-FNABs and 60.0% of the MCBs, a nonsignificant difference. There were no significant differences in the diagnostic yield concerning the tumor location or tumor size between the two methods. However, diagnostic specimens were significantly more frequently obtained in lesions with intraluminal growth than in those with extraluminal growth by the MCB method (P = 0.01). All four SMTs with extraluminal growth were diagnosed only by EUS-FNAB (P = 0.03). No complications were found in either method.

CONCLUSION: MCB may be chosen as an alternative diagnostic modality in tumors showing the intraluminal growth pattern regardless of tumor size, whereas EUS-FNAB should be performed for SMTs with extraluminal growth.

A case of gastric cancer with heterogeneous components of EB virus (+)/TP53 (+) and EB virus (-)/TP53 (-)

Epstein-Barr virus (EBV)-associated gastric adenocarcinoma is a histological subtype of gastric adenocarcinoma, in which all of the carcinoma cells are basically positive for EBV-encoded small RNA (EBER) by in situ hybridization. Although its typical histology has some overlap with gastric carcinoma with lymphoid stroma, absence of massive lymphoid infiltrate is sometimes observed either in whole or in part. EBV-associated adenocarcinoma is one of the four representative molecular pathological subtypes recently identified by comprehensive genomic analysis of gastric adenocarcinomas. According to the analysis, typical EBV-associated gastric adenocarcinoma constitutes an independent molecular pathological subgroup, which is mutually exclusive to TP53-mutated adenocarcinoma with chromosomal instability, another molecular pathological subtype in gastric adenocarcinomas. Here, we report a rare case of gastric cancer heterogeneously composed of EBER (+)/TP53 (+) and EBER (-)/TP53 (-) portions. The EBER (+)/TP53 (+) component with massive lymphoid infiltrate surrounded the EBER (-)/TP53 (-) component showing well to moderately differentiated tubular adenocarcinoma. Although collision of two independent gastric cancers could be the simplest and most possible explanation for this situation, we discussed another possibility. In the case of gastric collision tumors, concurrent development of EBER (+) gastric adenocarcinomas and EBER (-) gastric adenocarcinomas in a single stomach is a rare incident. Since presence of the EBER (+)/TP53 (+) tumor component is atypical in itself, we also discussed the mechanism of development of the clone.

Ultrafast spin-switching of a ferrimagnetic alloy at room temperature traced by resonant magneto-optical Kerr effect using a seeded free electron laser

Ultrafast magnetization reversal of a ferrimagnetic metallic alloy GdFeCo was investigated by time-resolved resonant magneto-optical Kerr effect measurements using a seeded free electron laser. The GdFeCo alloy was pumped by a linearly polarized optical laser pulse, and the following temporal evolution of the magnetization of Fe in GdFeCo was element-selectively traced by a probe free electron laser pulse with a photon energy tuned to the Fe M-edge. The results have been measured using rotating analyzer ellipsometry method and confirmed magnetization switching caused by ultrafast heating.

Bone marrow infiltration of CD20-negative follicular lymphoma after rituximab therapy: a histological mimicker of hematogones and B-cell acute lymphoblastic leukemia/lymphoma

Rituximab is a monoclonal antibody against CD20. Rituximab combined with CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) chemotherapy, termed R-CHOP, have improved the overall survival of patients with B-cell lymphoma in comparison with that of CHOP therapy. However, as with other molecularly-targeted therapies, resistance to rituximab could emerge sooner or later after rituximab administration. A number of mechanisms for rituximab resistance have been proposed, including downregulation of CD20 protein expression. Differential diagnosis of B-cell proliferation with reduced or lost CD20 expression includes not only B-cell lymphomas with CD20 downregulation, but also other tumorous and non-tumorous lesions. These include precursor B-cell neoplasms such as B acute lymphoblastic leukemia/lymphoblastic lymphoma (B-ALL/LBL) and hematogones, a normal precursor B-cell proliferation during regeneration of hematopoiesis, typically observed following bone marrow suppression by chemotherapy. It is important to distinguish these possibilities because distinct therapies are required for each. In this paper, we report a case where bone marrow infiltration of follicular lymphoma histopathologically mimicked hematogones or B-ALL/LBL when CD20 expression was downregulated in follicular lymphoma after R-CHOP therapy.

Chronic ileocolic intussusception due to transmural infiltration of diffuse large B cell lymphoma in a 14-year-old boy: a case report

Chronic intussusception, defined as intussusception continuing over 14 days, is rare in children. We herein report a case of chronic ileocolic intussusception caused by the transmural infiltration of diffuse large B cell lymphoma in a 14-year-old boy. The patient had been suffering from anorexia and intermittent abdominal pain for 5 weeks, during which his body weight decreased by around 7 kg. Upon admission to our hospital, ultrasonography and enhanced computed tomography (CT) of the abdomen showed ileocolic intussusception. A retrospective examination of abdominal CT led us to suspect that the intussusception had initially appeared 5 weeks before admission, presumably coinciding with the beginning of the patient’s abdominal symptoms. Since hydrostatic reduction was unsuccessful, laparotomy was performed, which showed unreducible ileocolic intussusception with a marked edematous ileum and mesentery. Ileocecal resection without lymph node dissection was carried out, and a histological examination of the resected specimen revealed the transmural infiltration of diffuse large B-cell lymphoma of the terminal ileum. The patient’s postoperative course was uneventful, and adjuvant chemotherapy was administered. This case illustrates the diagnostic challenges of confirming ‘chronic’ intussusception in older children.

Photoemission Circular Dichroism and Spin Polarization of the Topological Surface States in Ultrathin Bi2Te3 Films

Circular dichroism (CD) observed by photoemission, being sensitive to the orbital and spin angular momenta of the electronic states, is a powerful probe of the nontrivial surface states of topological insulators, but the experimental results thus far have eluded a comprehensive description. We report a study of Bi2Te3 films with thicknesses ranging from one quintuple layer (two-dimensional limit) to 12 layers (bulk limit) over a wide range of incident photon energy. The data show complex variations in magnitude and sign reversals, which are nevertheless well described by a theoretical calculation including all three photoemission mechanisms: dipole transition, surface photoemission, and spin-orbit coupling. The results establish the nontrivial connection between the spin-orbit texture and CD.

Occurrence of colon tumors in a 16-year-old Japanese boy after hematopoietic stem cell transplantation for Diamond Blackfan anemia at age of 4: a case report

Diamond Blackfan anemia (DBA) is a congenital pure red cell aplasia mainly caused by a mutation in ribosomal protein genes. One of the proposed mechanisms for red cell aplasia in DBA is apoptosis caused by constitutive activation of tumor suppressor TP53 protein following defective ribosome biogenesis. Because of this close relationship between ribosome biogenesis and TP53 activation, patients with DBA are considered to be cancer-prone. The association between bone marrow failure and tumor susceptibility in DBA appears paradoxical. Also, the detailed information is lacking on malignancy occurring in patients with DBA. Here, we report a case of a 16-year-old Japanese boy suffering from multiple colon tumors during the follow-up after hematopoietic stem cell transplantation for DBA at the age of 4. Well differentiated tubular adenocarcinoma was detected at the rectum 12 years after the transplantation, followed by multiple tubular adenomas of low to high grade throughout the colon. Endoscopic submucosal dissection was performed for these tumors and the lesions were completely resected. These tumors did not show diffuse and strong TP53 positivity by immunohistochemistry, suggesting that TP53 mutation was not involved in the tumorigenesis as observed in conventional colorectal cancers. Microsatellite instability test and immunohistochemical examination of β-catenin and MLH1 proteins of these tumors showed that WNT signaling or microsatellite instability was less likely to be involved in the present tumors as observed in conventional left-sided or right-sided colon cancers, respectively. To our knowledge, this is the first case report of colon tumors associated with DBA.

Distinct global DNA methylation status in B-cell lymphomas: immunohistochemical study of 5-methylcytosine and 5-hydroxymethylcytosine

Lymphomas are malignant neoplasms composed of lymphoid cells at various developmental stages and lineages. Recent advances in comprehensive genomic analyses in acute myeloid leukemia have revealed prevalent mutations in regulators of epigenetic phenomena including global DNA methylation status. The examples include mutations in isocitrate dehydrogenase 1 (IDH1), IDH2, and ten-eleven translocation 2. These mutations are proposed to inhibit conversion of 5-methylcytosine (5 mC) to 5-hydroxymethylcytosine (5 hmC), leading to global accumulation of 5 mC. These changes in global DNA methylation status can be visualized immunohistochemically using specific antibodies against 5 mC and 5 hmC. We examined the global DNA methylation status of B-cell lymphomas and that of their normal counterparts by immunohistochemistry for 5 mC and 5 hmC. Non-tumor lymphoid cells inside germinal centers (GC) in reactive lymphoid hyperplasia (RLH) were stained positive for 5 mC, but they were negative for 5 hmC. Similarly, follicular lymphomas, whose postulated normal counterparts are centrocytes in GCs, were 5 mC-positive but 5 hmC-negative by immunohistochemistry. This immunostaining pattern was also observed in Burkitt lymphoma. In contrast, non-tumor lymphoid cells in mantle zones were stained positive for 5 mC as well as for 5 hmC. Likewise, most mantle cell lymphomas, whose postulated normal counterparts are mantle zone B cells in RLH, were stained positive for 5 mC as well as for 5 hmC. This immunostaining pattern was also observed in chronic lymphocytic leukemia/small lymphocytic lymphoma. These results suggest that, in terms of 5 mC/5 hmC immunohistochemistry, B-cell lymphomas with different histological subtypes are associated with distinct global DNA methylation statuses that resemble those of their postulated normal counterparts.

A case of immunohistochemical false positive staining caused by incompatibility between a CD4 antibody and an autostainer

Precise immunophenotyping of tumor cells by immunohistochemistry is complementary to morphological examination. It is critical for the correct histopathological diagnosis of lymphomas. In this paper, we report a case of T-cell lymphoma whose histopathological diagnosis was confounded by an immunohistochemical pitfall: a false positive caused by incompatibility between an antibody and an autostainer. In this case, based on CD4 immunohistochemistry of the affected lymph nodes, the T-cell lymphoma was diagnosed as CD4-positive at the onset, while it appeared discordantly to be CD4-negative at the second relapse. We noticed that CD4 antibodies and autostainers of different suppliers (designated as suppliers X and Y) were used in an unqualified combination in immunohistochemistry at the onset: that is, the combination of an antibody supplied by X and an autostainer supplied by Y (designated as X-Y combination) was used at the onset. On the other hand, the Y-Y combination was at the second relapse. At the second relapse, flow cytometry of the affected lymph node showed infiltration of CD4-negative T-cell lymphoma. We reasoned that CD4 immunonegativity obtained by the Y-Y combination at the second relapse was specific, while CD4 immunopositivity by the X-Y combination at the onset was false positive. Immunohistochemical reexamination of the lymph node at the onset proved to be CD4-negative by not only the Y-Y but also X-X combinations, confirming our final diagnosis of nodal relapse of CD4-negative T-cell lymphoma. This case illustrates the importance of using compatible combinations of antibodies and autostainers in diagnostic immunohistochemistry.

Spontaneous regression of primary extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) colliding with invasive ductal carcinoma of the breast: a case report

Malignant lymphomas of the breast, whether they are primary or secondary, are rare diseases, constituting only around 0.1 to 0.15% of the primary neoplasm of the breast. Although the most prevalent histological subtype is diffuse large B-cell lymphoma, primary extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) also occurs in the breast as in other extranodal sites, comprising about 15% of malignant lymphomas of the breast. In many cases, primary MALT lymphoma of the breast is low grade lymphoma, localized in the breast with indolent behavior and good prognosis. Here we report a case of spontaneous regression of primary MALT lymphoma of the breast. The lymphoma collided with invasive ductal carcinoma in the breast. Both tumors were identified in the Vacora biopsy specimen before the operation. However, the lymphoma disappeared, while the carcinoma remained, in the resected mass. To our knowledge, this is the first case report of spontaneous regression of MALT lymphoma of the breast colliding with breast cancer.

Follicular lymphoma mimicking marginal zone lymphoma in lymph node: a case report

Nodal follicular lymphoma (FL) is typically composed of follicular or nodular proliferation of small cleaved lymphoid cells, presumably derived from germinal center (GC) B cells. The hallmark of FL is t(14;18)(q32;q21) chromosomal translocation, which juxtaposes anti-apoptotic gene BCL2 to immunoglobulin heavy chain (IGH) promoter. Reflecting this background, FL cells are immunohistochemically positive for BCL2 as well as GC B cell markers CD10 and BCL6. It is known that low grade B-cell lymphomas, including FL, chronic lymphocytic leukemia/small lymphocytic lymphoma, and marginal zone lymphoma, are sometimes associated with marginal zone differentiation or plasmacytic differentiation. The marginal zone differentiation obscures the morphological differences among these, providing diagnostic challenges for histopathologists. In this paper, we present a case of FL, originally mimicking marginal zone lymphoma in the axillary lymph node. Subsequent bone marrow biopsy showed paratrabecular infiltration of small to medium-sized lymphoid cells. Immunohistochemical analysis of the bone marrow biopsy together with histopathology and flow cytometry of the axillary lymph node led to a final diagnosis of FL with marginal zone differentiation in the axillary lymph node and its bone marrow infiltration. Our case illustrates and reconfirms the importance of clinicopathological correlation which leads to a correct diagnosis.

Primary extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue type with malakoplakia in the urinary bladder: a case report

Primary malignant lymphoma of the urinary bladder is a rare disease constituting less than 1% of neoplasms of the urinary bladder. The most prevalent histological subtype is extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue type (MALT lymphoma). It is frequently associated with chronic cystitis and predominantly occurs in females. On the other hand, malakoplakia is thought to be a reactive granulomatous lesion occurring most prevalently in the genitourinary tracts. It is frequently found in females and often associated with bacterial infection in immunosuppressive status. Here we report a rare case of concurrent primary MALT lymphoma and malakoplakia in the urinary bladder in a 78-year-old Japanese female. Presumably, both lymphoma and malakoplakia are considered to be involved in the antecedent cystitis and might contribute to the development of the urinary bladder tumor of the patient, leading to the occlusion of the right ureter with subsequent hydronephrosis.

Primary follicular lymphoma of the spleen incidentally found in a patient with alcohol- and hepatitis C-related liver cirrhosis

Primary splenic lymphoma is rare as non-Hodgkin lymphomas. Splenic infiltration of lymphoma cells may cause splenomegaly in many cases. However, splenomegaly is caused not only by tumor involvement but also by non-tumorous disorders. One of the most prevalent non-neoplastic causes is portal hypertension mostly due to liver cirrhosis. On the other hand, liver cirrhosis may underlie various extrahepatic manifestations including development of B-cell non-Hodgkin lymphomas. Here, we report a case of primary follicular lymphoma of the spleen in a patient with liver cirrhosis related to hepatitis C and alcohol. The lymphoma was incidentally found in an enlarged spleen resected palliatively to alleviate symptomatic pancytopenia of the patient. The main characteristic of our case is an incidental finding of a rare situation brought by careful pathological examination. Our case illustrates the importance to recognize a possibility of co-occurrence of chronic liver disease and extrahepatic lymphoma.

Diffuse alveolar damage in a patient with Epstein Barr virus (EBV)-positive diffuse large B-cell lymphoma,severely low serum folate, and megaloblastic anemia: a case report of autopsy

We report a case of a 49-year-old Japanese man, who was admitted to our hospital because of severe dyspnea. He was found to have severely low serum folate and megaloblastic anemia, which was at first suspected to cause his dyspnea. It was assumed that severely low serum folate might be related to his malnutrition, probably caused by habitual alcohol consumption. He died in several days because of acute respiratory distress syndrome. Autopsy revealed diffuse alveolar damage (DAD) in the lungs and systemic lymph node swelling by EBV-positive diffuse large B-cell lymphoma, in addition to megaloblastic anemia in the bone marrow. Together with histological hemophagocytosis and high level of serum iron and ferritin, DAD was considered to be caused by hypercytokinemia triggered by the presence of EBV-positive diffuse large B-cell lymphoma. On the other hand, pathological findings suggestive of habitual alcohol consumption were not apparent. We considered that low serum folate in this case was not by the low intake but by increased consumption of folate by rapid progression of the lymphoma.

Analysis of the human intestinal microbiota from 92 volunteers after ingestion of identical meals

The intestinal microbiota composition of 92 volunteers living in Japan was identified following the consumption of 'identical meals' (1,879 kcal/day) for 3 days. When faecal samples were analysed by terminal restriction fragment length polymorphism with several primer-restriction enzyme systems and then clustered, the patterns could be divided into 2 clusters. Contribution tests and partition modelling showed that OTU211 of the 35f-MspI system and OTU237 of the 35f-AluI system were key factors in the distribution of these groups. However, significant differences among these groups in terms of body mass index and age were not observed.

A case of synchronous bilateral lung cancers: EML4-ALK positive adenocarcinoma in the right lung and adenocarcinoma in situ (the former bronchioloalveolar carcinoma) in the left lung

BACKGROUND

Recently it has been revealed that lung adenocarcinomas with distinct gene mutations or fusions are associated with particular histopathological entities. For example, epidermal growth factor receptor (EGFR) gene mutations are often associated with well differentiated adenocarcinoma of the lung with bronchioloalveolar pattern. On the other hand, echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) fusion gene in a subset of lung adenocarcinoma is related to mucinous cribriform histology.

CASE PRESENTATION

Reported herein is a case of synchronous EML4-ALK positive lung adenocarcinoma and adenocarcinoma in situ in the bilateral lungs of a 55-year-old Japanese woman. The woman had EML4-ALK positive lung adenocarcinoma in the right lower lung while adenocarcinoma in situ in the left upper lung, which was EML4-ALK negative.

CONCLUSION

To our knowledge, this is the first report of synchronous, bilateral lung adenocarcinomas composed of EML4-ALK positive and negative ones.

Role of neuropilin-2 in the ipsilateral growth of midbrain dopaminergic axons

Axonal projections in the CNS can be categorized as either crossed or uncrossed. Crossing and uncrossing of axons has been explained by attractive and repulsive molecules like Netrin-1 and Slits, which are secreted by midline structures. However, uncrossed projections can be established even in double knockout mice of slit1 and slit2 or of roundabout1 (robo1) and robo2, two receptors for Slits. Here, we found that a novel mechanism mediated by Neuropilin-2 (Nrp2) contributes to the formation of uncrossed projections of midbrain dopaminergic neurons (mDANs). Nrp2 transcriptional activities were detected in a subset of mDANs, and its protein was expressed in mDAN axons growing through the ipsilateral diencephalon. In nrp2(lac) (Z) (/lac) (Z) mice, mDAN axons aberrantly grew toward the ventral midline and even crossed it, suggesting that Nrp2 is necessary for the development of mDAN ipsilateral projections. We investigated the involvement of Semaphorin 3B (Sema3B) and Sema3F, two ligands of Nrp2, by analysing mDAN axon trajectories in single or double knockout mice. In both cases, mDAN axons still projected ipsilaterally, suggesting the involvement mechanisms independent of these Sema3s. Nrp2-deficient mDAN axons retained their responsiveness to Slit2, demonstrating that aberrant mDAN axons in nrp2(lac) (Z) (/lac) (Z) mice were not indirectly mediated by alterations in Slit/Robo signaling. Taken together, our results indicate that a novel mechanism mediated by Nrp2 contributes to the establishment of uncrossed projections by mDAN axons.

Metastatic lobular carcinoma of the breast masquerading as a primary rectal cancer

Background

Colorectal metastasis of lobular carcinoma of the breast is a diagnostic challenge. It may macroscopically simulate primary colon cancer or inflammatory bowel disease. In some cases, the interval between the primary breast cancer and metastatic colorectal lesions is so long that the critical records for diagnosis including history might be lost or missed.

Case presentation

Reported herein is a case of metastatic lobular carcinoma of the breast masquerading as a primary rectal cancer developed in a 62-year-old Japanese woman. The case initially presented as a circumferential rectal lesion, and information on the patient’s history of breast cancer was not noted. As the result of endoscopic biopsy, diagnosis of poorly differentiated rectal adenocarcinoma was made. The lesion was surgically resected after chemo-radiotherapy. Histopathological examination of the resected specimen with hematoxylin and eosin (HE) stain revealed a single-file arrangement of the tumor cells, reminiscent of lobular carcinoma of the breast. Immunohistochemical analysis revealed an immunophenotype consistent with lobular carcinoma of the breast. Because further review of the patient’s history revealed an occurrence of ‘poorly differentiated adenocarcinoma of the breast’, which she had experienced 24 years earlier, the final diagnosis of the lesion was made as rectal metastasis from lobular breast carcinoma.

Conclusions

Poorly differentiated adenocarcinoma of the colorectum is rarer than that of the stomach. Linitis plastica-type cancer of the colorectum is also rarer than that of the stomach. A lesson from the present case is that before we conclude a linitis plastica-type cancer of poorly differentiated type as a primary colorectal cancer, it is critical to exclude a possibility of metastatic colorectal cancer.

Clinicopathological characteristics of rectal carcinoid patients undergoing surgical resection

The aim of this study was to clarify the clinical aspects, histopathological features and prognosis of patients with rectal carcinoids, focusing on properties associated with metastasis, in order to gain insights into appropriate management. A total of 20 patients (15 males, 5 females; mean age, 54.9 years; range, 23-71) who underwent surgery for rectal carcinoid tumors at the Department of Colorectal Surgery, Hyogo College of Medicine, between May 2000 and January 2011 were analyzed. Ki-67 immunostaining was performed in 13 cases with available tumor tissue specimens. Of the 20 patients, a radical operation including rectal resection with a lymphadenectomy was performed in 16. The mean tumor size was 11.9 mm (3-25 mm) and lymph node metastasis was confirmed in 9 cases, including 3 with lesions no greater than 7 mm in diameter. Overall, 16 (80%) of the tumors were localized in the submucosal layer and 4 (20%) involved the proper muscle layer. Ki-67 labeling index and lymphovascular invasion were shown to be associated with lymph node and/or distant metastasis by multiple logistic regression analysis, but were not statistically significant in ANOVA findings. Lymph node metastasis from rectal carcinoids, even those smaller than 10 mm in diameter, was not a rare event. More attention should be given to decision-making, including the possibility of endoscopic resection for the treatment of rectal carcinoid tumors regardless of size.

Controlling the topology of Fermi surfaces in metal nanofilms

The properties of metal crystals are governed by the electrons of the highest occupied states at the Fermi level and determined by Fermi surfaces, the Fermi energy contours in momentum space. Topological regulation of the Fermi surface has been an important issue in synthesizing functional materials, which we found to be realized at room temperature in nanometer-thick films. Reducing the thickness of a metal thin film down to its electron wavelength scale induces the quantum size effect and the electronic system changes from three to two-dimensional, transforming the Fermi surface topology. Such an ultrathin film further changes its topology through one-dimensional (1D) structural deformation of the film when it is grown on a 1D substrate. In particular, when the interface has 1D metallic bands, the system is additionally stabilized by forming an electron energy gap by hybridization between 1D states of the film and substrate.

Electronic structure study of ultrathin Ag(111) films modified by a Si(111) substrate and √3 × √3-Ag2Bi surface

Angle-resolved photoemission spectroscopy experiments show that the electronic structure of a Ag(111) film grown on Si(111) is markedly perturbed by the formation of a √3 × √3-Ag(2)Bi Rashba-type surface alloy. Four spin-split surface states, with different band dispersions and energy contours, intercept and hybridize selectively with the sp-derived quantum well states of the Ag layer. Detailed two-dimensional band mapping of the system was carried out and constant energy contours at different energies result in hexagonal-, star- and flower-like distortions of the quantum well states as a result of various interactions. Further wavy-like modulations of the electronic structure of the film are found to originate from umklapp reflections of the Ag film states according to the surface periodicity.

Hydrogen-induced surface metallization of SrTiO3(001)

Surface metallization of SrTiO3(001) by hydrogen adsorption is experimentally confirmed for the first time by photoemission spectroscopy and surface conductivity measurements. The metallic state is assigned to a quantized state in the space-charge layer induced by electron doping from hydrogen atoms. The measured two-dimensional (2D) conductivity is well above the 2D Ioffe-Regel limit indicating that the system is in a metallic conduction regime. The mean free path of the surface electron is estimated to be several nanometers at room temperature.