Identification of characteristic subepithelial surface granulomatosis in immune-related adverse event-associated enterocolitis.

Immune checkpoint inhibitors (ICIs) have provided an additional treatment option for various types of human cancers. However, ICIs often induce various immune-related adverse events (irAEs). Enterocolitis is a major irAE with poorly understood histopathological characteristics. In this study, we retrospectively investigated the histopathology of colon tissue samples from 17 patients treated with ICIs. There were two major histological patterns of colitis: an ulcerative colitis-like pattern and a graft vs host disease-like pattern. Although these two patterns of colitis were mutually exclusive, both patterns often showed a characteristic that we call "subepithelial surface granulomatosis" (SSG), which has not been reported in other types of colitis. SSG was found even in colon tissue without symptoms or endoscopic findings of colitis. Given the increasing reports of sarcoid reaction or exacerbation of tuberculosis after treatment with ICIs, granuloma formation could be a histological hallmark of systemic immune activation by ICIs. Although statistical significance was not obtained, probably because of the small sample size, SSG may be a surrogate biomarker of systemic anticancer immune activation. We propose that a prospective study with larger sample size be performed.

[Philadelphia chromosome-positive acute lymphoblastic leukemia with basophilic blast features].

A 62-year-old man was referred to our hospital due to pancytopenia and abnormal leukocyte fraction in December 2016. Bone marrow aspiration showed a massive proliferation of blast cells (96%) with rich myeloperoxidase-negative basophilic granules. He was diagnosed with acute basophilic leukemia, and an appropriate treatment for acute myelogenous leukemia was initiated. Blast cells were positive for minor BCR-ABL mutations, and chemotherapy using imatinib was initiated on day 7. The treatment was effective and complete remission was achieved on day 30. The ultrastructural features of blast cells showed typical basophilic granules with high electron density structure on electron microscopy. However, immunohistochemical analysis were positive for CD79a, PAX5, and TdT expression. Rearrangements of immunoglobulin heavy chain and T-cell receptor genes were detected, prompting the diagnosis of Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL) with basophilic change. The patient continued to be treated with the imatinib combination regimen, as well as umbilical cord blood transplantation. The patient has currently achieved recurrence-free survival. This case represents a rare divergence between morphology and molecular condition.

Loss of sorting nexin 5 stabilizes internalized growth factor receptors to promote thyroid cancer progression.

Thyroid carcinoma is the most common endocrine malignancy and its prevalence has recently been increasing worldwide. We previously reported that the level of sorting nexin 5 (Snx5), an endosomal translocator, is preferentially decreased during the progression of well-differentiated thyroid carcinoma into poorly differentiated carcinoma. To address the functional role of Snx5 in the development and progression of thyroid carcinoma, we established Snx5-deficient (Snx5-/- ) mice. In comparison to wild-type (Snx5+/+ ) mice, Snx5-/- mice showed enlarged thyroid glands that consisted of thyrocytes with large irregular-shaped vacuoles. Snx5-/- thyrocytes exhibited a higher growth potential and higher sensitivity to thyroid-stimulating hormone (TSH). A high content of early endosomes enriched with TSH receptors was found in Snx5-/- thyrocytes, suggesting that loss of Snx5 caused retention of the TSH receptor (TSHR) in response to TSH. Similar data were found for internalized EGF in primary thyrocytes. The increased TSH sensitivities in Snx5-/- thyrocytes were also confirmed by results showing that Snx5-/- mice steadily developed thyroid tumors with high metastatic potential under high TSH. Furthermore, a thyroid cancer model using carcinogen and an anti-thyroidal agent revealed that Snx5-/- mice developed metastasizing thyroid tumors with activation of MAP kinase and AKT pathways, which are postulated to be major pathways of malignant progression of human thyroid carcinoma. Our results suggest that thyrocytes require Snx5 to lessen tumorigenic signaling driven by TSH, which is a major risk factor for thyroid carcinoma. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Cyclopiazonic acid biosynthesis gene cluster gene cpaM is required for speradine A biosynthesis.

Speradine A is a derivative of cyclopiazonic acid (CPA) found in culture of an Aspergillus tamarii isolate. Heterologous expression of a predicted methyltransferase gene, cpaM, in the cpa biosynthesis gene cluster of A. tamarii resulted in the speradine A production in a 2-oxoCPA producing A. oryzae strain, indicating cpaM is involved in the speradine A biosynthesis.

Intratumoral heterogeneity of HER2 protein and amplification of HER2 gene in salivary duct carcinoma.

Salivary duct carcinoma (SDC) is an aggressive adenocarcinoma of the salivary glands, and accounts for 1-3% of all malignant salivary gland tumors, resembling morphologically invasive ductal carcinoma (IDC) of the breast. In contrast to IDC of the breast and gastric carcinoma (GC), the study of human epidermal growth factor receptor 2 (HER2) in SDC has not progressed. Therefore, we investigated the relationship between HER2 protein expression and amplification of the HER2 gene, and compared them in terms of intratumoral heterogeneity (ITH) in 13 cases of SDC using immunohistochemistry and dual color in situ hybridization. We found seven cases with protein overexpression (53.8%) and five cases with gene amplification (38.5%) in accordance with ASCO/CAP guidelines. ITH of HER2 protein expression was seen in seven cases (53.8%). Interestingly, the ratio of the HER2 gene showed homogenous distribution with or without the presence of ITH of HER2 protein expression. SDC tends to have more ITH of HER2 protein similarly to GC, in contrast to IDC of the breast. ITH of HER2 protein in SDC has no heterogeneity of the HER2 gene amplification. The mechanism of HER2 protein expression in SDC might proceed through a more complex pathway relative to that of IDC of the breast.

Over-expression of BACH2 is related to ongoing somatic hypermutation of the immunoglobulin heavy chain gene variable region of de novo diffuse large B-cell lymphoma.

The basic region-leucine zipper (bZip) factor BTB, CNC homology 2 (BACH2) is known to have important roles in class switch recombination and somatic hypermutation (SHM) of the immunoglobulin (Ig) gene. In this study, we investigated the relationship between the expression of BACH2 and the status of SHM of the Ig heavy chain gene variable region (IgHV) for SHM in diffuse large B-cell lymphoma (DLBCL). We examined 20 cases of DLBCL, 13 of which were germinal center B-cell (GCB) DLBCL and 7 were non-GCB DLBCL. Seven cases were negative, 6 were positive (cytoplasmic expression) and 7 were strongly positive (both nuclear and cytoplasmic expression) for BACH2. Confirmed mutation (CM) was identified in 8 cases and the CM index (number of confirmed mutations per 10 subclones) was distributed from 0 to 5. A CM index of 7 strongly positive (over-expression) cases with BACH2 were distributed from 0 to 5, and that of 7 negative and 6 positive cases were distributed from 0 to 1. Over-expression of BACH2 was statistically related to CM index (P = 0.008). In conclusion, over-expression of BACH2 is critical for ongoing SHM of IgHV in DLBCL, and our data suggest that BACH2 may play an essential role for SHM of the Ig gene in B-cell lymphoma.

Laparoscopic cholecystectomy after transcatheter arterial embolisation for haemobilia due to a pseudoaneurysm in the gallbladder: A case report.

Pseudoaneurysms of the cystic artery are a rare but significant complication of acute cholecystitis. Laparoscopic cholecystectomy may be a safe alternative to open cholecystectomy in such cases. We report the case of a female patient in her seventies, who presented with anaemia, jaundice, and hepatic dysfunction during hospitalisation for right knee pyogenic arthritis. The patient had no pain in the right upper quadrant. Her serum haemoglobin level was 6.5 g/dL, and upper gastrointestinal endoscopy revealed no abnormalities. Six days later, jaundice worsened, and endoscopic retrograde cholangiopancreatography revealed bloody bile. An endoscopic biliary drainage tube was inserted at the discretion of the gastroenterology department. Contrast-enhanced computed tomography revealed a haematoma in the gallbladder and a pseudoaneurysm in the lateral wall of the gallbladder. On the same day, the endoscopic biliary drainage tube was replaced with an endoscopic nasobiliary drainage tube, which indicated the degree of haemorrhage and enabled lavage of the lumen in cases of obstruction. The next day, angiography revealed a pseudoaneurysm of the deep branch of the cystic artery and coil embolisation was performed at the periphery of the cystic artery. Uninterrupted laparoscopic cholecystectomy was performed. Although laparoscopic cholecystectomy is difficult when bleeding is uncontrolled, it was safely performed following haemostasis using transcatheter arterial embolisation. Laparoscopic cholecystectomy is feasible in haemodynamically stable patients with cystic artery pseudoaneurysms after transcatheter arterial embolisation.

Immunohistochemical analysis of arachidonate 5-lipoxygenase expression in B-cell lymphomas: Implication for B cell differentiation and its analogy with lymphomagenesis.

Arachidonate 5-lipoxygenase (ALOX5) is a cardinal enzyme in the synthesis of leukotrienes, which are powerful immune-regulating lipid mediators. We previously reported that ALOX5 is preferentially expressed in B lymphocytes in the mantle zone of human lymphoid tissue. In the context of physiological relevance, the loss of the Alox5 gene in mice significantly impairs the development of follicular B helper T cells and antibody production. However, ALOX5 expression in B-cell lymphomas has not been investigated in detail. In this study, we examined ALOX5 expression in representative B-cell lymphomas and non-neoplastic lymphoid tissues by immunohistochemistry with a commercially available anti-ALOX5 antibody that can be used on formalin-fixed paraffin-embedded specimens. Interestingly, 22/22 cases of mantle cell lymphoma, 7/7 cases of chronic lymphocytic leukemia/small cell lymphoma, and 20/20 cases of follicular lymphoma expressed ALOX5. A small proportion of extranodal marginal zone lymphoma/mucosa-associated lymphoid tissue lymphoma or nodal marginal zone lymphoma cases were positive for ALOX5 (2/13 or 1/3, respectively). In contrast, no cases with diffuse large B-cell lymphoma, regardless of germinal center B cell (GCB) or non-GCB type, expressed ALOX5 (0/25 cases). These findings suggest that ALOX5 may be a novel marker for identifying the cell of origin of B-cell lymphoma. Further investigation is required to clarify the biological significance of ALOX5 expression in lymphoma cells.

Sorting nexin 5 of a new diagnostic marker of papillary thyroid carcinoma regulates Caspase-2.

Papillary thyroid carcinoma (PTC) is a well-differentiated endocrine malignant tumor that develops from thyroid follicular epithelium. The tumor represents the most common type of endocrine malignancy; however, its tumorigenesis is not fully elucidated. The aim of this study was to address the functional role of the sorting nexin (SNX) family in PTC because of recent experimental evidence suggesting that the SNX family members actively control endocytotic transportation as well as cell fate. Expression profiles of SNX family members of PTC showed a significant quantity of transcripts of SNX5. Further immunohistochemical analysis with an SNX5-specific monoclonal antibody established in this study consistently demonstrated the preferential expression of SNX5 in PTC (94.2%, 113/120 cases) as indicated by studies on 440 cases of various tumors. In contrast, other major carcinomas originating from the lung (2.6%, 1/38 cases), breast (5.1%, 2/39 cases), and intestine (4.2%, 1/24 cases) scarcely expressed SNX5. When we investigated models of murine thyroid tumors induced by the administration of carcinogens, high expression of Snx5 was also observed in well-differentiated thyroid tumors, further implying that the tumorigenesis of the thyroid gland was tightly associated with the abundance of SNX5/Snx5. Moreover epithelial cells expressing excess SNX5 showed high levels of Caspase-2 of an initiator caspase. Collectively these findings suggest that the evaluation of SNX5 expression would support pathological diagnosis of primary and secondary PTC.

Arachidonate 5-lipoxygenase establishes adaptive humoral immunity by controlling primary B cells and their cognate T-cell help.

In this study, we report the unique role of arachidonate 5-lipoxygenase (Alox5) in the regulation of specific humoral immune responses. We previously reported an L22 monoclonal antibody with which human primary resting B cells in the mantle zones of lymphoid follicles are well-defined. Proteomics analyses enabled identification of an L22 antigen as Alox5, which was highly expressed by naive and memory B cells surrounding germinal centers. Cellular growth of mantle cell lymphoma cells also seemed to depend on Alox5. Alox5(-/-) mice exhibited weak antibody responses specific to foreign antigens at the initial and recall phases. This was probably attributable to the low number of follicular and memory B cells and the functional loss of interleukin-21-mediated responses of follicular B cells. Moreover, Alox5(-/-) mice could not fully foster the development of follicular B helper T (Tfh) cells even after immunization with foreign antigens. Further experiments indicated that Alox5 affected mortality in experimentally induced enterocolitis in germ-prone circumstances, indicating that Alox5 would endow immunologic milieu. Our results illustrate the novel role of Alox5 in adaptive humoral immunity by managing primary B cells and Tfh cells in vivo.

Neuroendocrine Carcinoma at the Sphenoid Sinus Misdiagnosed as an Olfactory Neuroblastoma and Resected Using High-Flow Bypass.

In the diagnosis of olfactory neuroblastoma (ONB), the presence of S-100-positive sustentacular cells surrounding the tumor is important; however, these are also present in normal nasal sinus epithelium. Although ONB often has a different final diagnosis, complete resection of the tumor has a good prognosis and minimally affects the patient's treatment plan. When the tumor extends around the internal carotid artery (ICA), complete resection is difficult due to the high risk of vascular injury; revascularization using high-flow bypass can avoid this complication. In the present case, the tumor was located in the left sphenoid sinus and extended around the ICA. Preoperative biopsy tissue was positive for neuroendocrine markers and slightly positive for S-100 protein, leading to a diagnosis of ectopic ONB. High-flow bypass revascularization with trapping of the ICA allowed complete tumor resection. The postoperative histopathological diagnosis was neuroendocrine carcinoma, showing no S-100 protein-positive cells. There was no sign of recurrence at 30 months after surgery without additional treatment. This case demonstrates that the presence of S-100 protein-positive cells in ONB may be misleading. Although misdiagnosis of ectopic ONB should be anticipated, a complete resection of the tumor is an effective treatment strategy.

Spindle cell tumor with histiocytic and myogenic marker expression in the lymph node of a human T-cell leukemia virus type 1 carrier.

Carriers of oncogenic human T-cell leukemia virus type 1 (HTLV-1) can develop adult T-cell leukemia/lymphoma (ATLL). While an increasing number of animal models of HTLV-1 infection have revealed that malignant tumors with a histiocytic phenotype can arise, they have not been reported in humans. Here, we present a 79-year-old female HTLV-1 carrier who presented with a swollen lymph node. Histological examination revealed that the lymph node was replaced with a malignant spindle cell tumor, but not ATLL. Immunohistochemical analysis indicated that the tumor was positive for histiocytic (CD68 and CD163) and myogenic (α-smooth muscle actin, desmin, and caldesmon) markers, suggesting some differential diagnoses. We could not reach a definitive diagnosis under the current notion of the disease entity. In addition, we could not provide an exact causal relationship between HTLV-1 infection and the development of the current tumor. Nevertheless, this tumor may be a human counterpart of murine HTLV-1-related histiocytic tumors. Curiously, the tumor showed a good response to chemotherapy with the combination of cyclophosphamide, vincristine, and prednisone, a standard approach for ATLL. This case might represent a novel entity of an HTLV-1-related malignant tumor. Further accumulation of case reports will certainly contribute to our understanding of human HTLV-1-related disease and the mechanism of viral oncogenesis.

Improvement of abnormal cervical cytology possibly due to a graft-versus-tumor effect: A case report and literature review.

The cervical cytology of our patient transformed from squamous cell carcinoma to negative for intraepithelial lesion or malignancy, possibly due to the graft-versus-tumor effect following allogeneic stem cell transplantation.

A Radical Approach to Acute Lymphoblastic Leukemia Treatment: A Case Study of a Veterinarian Specializing in Livestock who Developed Disseminated Mucormycosis during Induction Therapy.

Mucormycosis has emerged as the third-most common fungal mycosis and is one of the most fatal molds. We herein report a case study of a 30-year-old woman who was a veterinarian, specializing in livestock, who developed disseminated mucormycosis during induction therapy for acute lymphoblastic leukemia. We successfully used a radical approach for treatment, including a surgical procedure and allogeneic transplantation, with continuous administration of antifungal agents. Reports of successful treatments are extremely rare, and our case has had the longest documented remission from disseminated disease. We speculate that our case's occupational environment may represent a risk factor for development of mucormycosis.

Wild-type AIRE cooperates with p63 in HLA class II expression of medullary thymic stromal cells.

During T cell development in the thymus, autoreactive T cells are deleted through a mechanism that is actively supported by medullary epithelial cells. These epithelial cells possess particular transcription factors including autoimmune regulator (AIRE), which is responsible for regulating expression of self-antigens, as well as p63, a p53-like molecule. Here we present evidence suggesting interaction of AIRE with p63 through a SAND domain and a transactivation domain, respectively. Interestingly an AIRE molecule with a mutated SAND domain of G228W, whose genetic alteration is inherited in an autosomal dominant manner, could not establish a complex with p63 as indicated by immunoprecipitation and molecular modeling analyses. Further in vitro study indicated that the G228W mutation led to downregulation of the transcription levels of CIITA and, accordingly, the cell surface expression of HLA class II molecules in thymic epithelial cells with p63. This indicates novel involvement of AIRE and p63 in the regulation of HLA class II, and suggests that defects in the AIRE-p63 interaction may lead to malfunction of HLA-based selection of self-reactive helper CD4(+) T cells in the thymus.

Molecular pathological approaches to human tumor immunology.

Research on human tumor immunology has greatly advanced in the past two decades. Many immunogenic tumor antigens have been identified, and some of these antigens entered in clinical trials. Consequently, it has been shown that these antigens can inhibit tumor growth in patients to some extent, indicating that they act as potent immunogenic therapeutic vaccines in cancer patients with malignancies originating from various tissues. These patients had antigen-specific cytotoxic T-lymphocyte (CTL) responses when assessed on tetramer, enzyme-linked immunospot (ELISPOT), T-cell clonotype and CTL induction efficiency. Thus, it has become clear that human tumor vaccines can evoke clinical and immunological anti-tumor responses in patients. The tumor regression effects of tumor vaccines, however, are generally low, and it is obvious that current vaccination protocols are generally too weak to provide substantial and satisfactory clinical benefits. This means that other drastic and more potent clinical and immunological protocols are required in cancer immunotherapy. To find such efficient protocols the basic immunological and biological properties of cancers must be investigated. In the present review the identification of human tumor antigens recognized on CTL and the clinical trials are introduced. Next, the most recent analysis of human cancer-initiating cell (cancer stem cell)-associated antigens is described. These antigens might be able to act as 'universal, general and fundamental' tumor antigens. Also present is the authors' recent study for increasing cross-presentation efficiency in dendritic cells and subsequent enhancement of human leukocyte antigen (HLA)-class I-restricted peptide antigenicity by using HSP90 and ORP150 molecular chaperones that act as endogenous Toll-like receptor ligands. In addition to the aforementioned manipulation of the positive loop of tumor immunity, it is necessary to regulate and intervene in the negative loop. In particular, the potential of the expression of HLA class I molecule regulation by epigenetic mechanisms will be discussed. Finally, the type of basic and clinical tumor immunology research highly required currently, and in the very near future, are described.

Exceptionally rapid response to pembrolizumab in a SMARCA4-deficient thoracic sarcoma overexpressing PD-L1: A case report.

SMARCA4-deficient thoracic sarcoma (SMARCA4-DTS) is a new clinical entity characterized by SMARCA4 inactivation and has a dismal prognosis because of rapid growth. Effective treatments for SMARCA4-DTS have not yet been developed. Most recently, anti-programmed cell death 1 receptor (PD-1) blockade has been effective for SMARCA4-deficient lung cancer and malignant rhabdoid tumor-like tumors. Here, we describe a patient with SMARCA4-DTC who experienced a marked response to the administration of pembrolizumab. A 70-year-old female was referred to our department for treatment of SMARCA4-DTC. Positron emission tomography-computed tomography had revealed a left mediastinal tumor, peritoneal dissemination and multiple cutaneous metastases at diagnosis. Immunohistochemical analyses revealed 60% of tumor cells expressed programmed cell death ligand 1 (PD-L1). The patient was given pembrolizumab as first-line treatment. Pembrolizumab suppressed tumor growth dramatically, with only one dose leading to a partial response. Our case suggests the immunohistochemical analysis of PD-L1 expression be undertaken for patients with SMARCA4-DTS and that pembrolizumab treatment may be a promising strategy for PD-L1-positive SMARCA4-DTS.

Spindle cell rhabdomyosarcoma in a lumbar vertebra with FUS-TFCP2 fusion.

A 70-year-old woman developed severe buttock pain that progressed to a walking disturbance. Radiographs and computed tomography scans revealed an osteolytic lesion with osteosclerosis extending from the body to the arch of the fifth lumbar vertebra. Magnetic resonance imaging showed multinodular masses in the fifth lumbar vertebral body extending into the spinous processes and right transverse process. The masses were hypointense to isointense on T1-weighted images and hypointense to hyperintense on T2-weighted images. Histologic examination of biopsy specimens showed destruction of the trabecula of the vertebral bone by a fascicular and solid proliferation of spindle tumor cells and scattered rhabdomyoblasts, in a fibrotic background. The tumor cells were immunoreactive for keratins, vimentin, desmin, MyoD1, myogenin, and anaplastic lymphoma kinase. Fluorescence in situ hybridization detected split signals for FUS and TFCP2 in 80% and 64% of the tumor cells, respectively, suggesting FUS-TFCP2 fusion. Reverse transcription-polymerase chain reaction revealed a FUS-TFCP2 fusion. The final diagnosis was spindle cell rhabdomyosarcoma of a lumbar vertebra with a FUS-TFCP2 fusion. A spindle cell rhabdomyosarcoma with a FUS-TFCP2 fusion in a vertebral bone is rare and should be differentiated from metastatic carcinoma, particularly in the elderly.

Composite Follicular Lymphoma and CD5-Positive Nodal Marginal Zone Lymphoma.

Composite CD10-positive low-grade B-cell and CD5-positive low-grade B-cell lymphoma is extremely rare. We report a case of a composite follicular lymphoma (FL) and CD5-positive nodal marginal zone lymphoma (NMZL) in a resected inguinal lymph node of a 72-year-old Japanese male. Histologically, multiple follicles had reactive-germinal centers with tingible body macrophages, a thin mantle zone and a wide marginal zone. The wide marginal zone consisted of medium-sized cells having slightly indented nuclei and clear cytoplasm, indicating monocytoid cells with CD5-positive B-cells. Several follicles had germinal centers filled with many centrocytes, with CD10-positive B-cells. Polymerase chain reaction/sequence analysis of the immunoglobulin heavy chain gene obtained from microdissected regions of CD5-positive NMZL and FL showed different sequences within the CDR3 region. To our knowledge, this is the first report of FL and CD5-positive NMZL.