Long operating lifetime mid-infrared LEDs based on black phosphorus

Black phosphorus (BP) is a narrow bandgap layered semiconductor promising for mid-infrared optoelectronic applications. BP-based devices have been shown to surpass state-of-the-art mid-infrared detectors and light-emitting diodes (LEDs) in terms of performance. Despite their device advantages, the material's inherent instability in the air could hinder its use in practical optoelectronic applications. Here, we investigated the impact of passivation on the device lifetime of BP LEDs, which deteriorate in a matter of seconds without using passivation. The lifetime is significantly extended with an Al2O3 passivation layer and nitrogen packaging via atomic layer deposition and ultra-violet curable resin sealing. The operational lifetime (half-life) at room temperature is extrapolated to be ~15,000 h with an initial power density of 340 mW/cm2 based on accelerated life testing. The present results indicate that efficient BP optoelectronics can be highly robust through simple and scalable packaging technologies, with important practical implications for mid-infrared applications.

Multipole polaron in the devil's staircase of CeSb

Rare-earth intermetallic compounds exhibit rich phenomena induced by the interplay between localized f orbitals and conduction electrons. However, since the energy scale of the crystal-electric-field splitting is only a few millielectronvolts, the nature of the mobile electrons accompanied by collective crystal-electric-field excitations has not been unveiled. Here, we examine the low-energy electronic structures of CeSb through the anomalous magnetostructural transitions below the Néel temperature, ~17 K, termed the 'devil's staircase', using laser angle-resolved photoemission, Raman and neutron scattering spectroscopies. We report another type of electron-boson coupling between mobile electrons and quadrupole crystal-electric-field excitations of the 4f orbitals, which renormalizes the Sb 5p band prominently, yielding a kink at a very low energy (~7 meV). This coupling strength is strong and exhibits anomalous step-like enhancement during the devil's staircase transition, unveiling a new type of quasiparticle, named the 'multipole polaron', comprising a mobile electron dressed with a cloud of the quadrupole crystal-electric-field polarization.

Band-dependent superconducting gap in SrFe2(As0.65P0.35)2 studied by angle-resolved photoemission spectroscopy

The isovalent-substituted iron pnictide compound SrFe₂(As_1−xP_x)₂ exhibits multiple evidence for nodal superconductivity via various experimental probes, such as the penetration depth, nuclear magnetic resonance and specific heat measurements. The direct identification of the nodal superconducting (SC) gap structure is challenging, partly because the presence of nodes is not protected by symmetry but instead caused by an accidental sign change of the order parameter, and also because of the three-dimensionality of the electronic structure. We have studied the SC gaps of SrFe₂(As_0.65P_0.35)₂ in three-dimensional momentum space by synchrotron and laser-based angle-resolved photoemission spectroscopy. The three hole Fermi surfaces (FSs) at the zone center have SC gaps with different magnitudes, whereas the SC gaps of the electron FSs at the zone corner are almost isotropic and k_z-independent. As a possible nodal SC gap structure, we propose that the SC gap of the outer hole FS changes sign around the Z-X [(0, 0, 2π) − (π, π, 2π)] direction.

Measurements of Nonsinglet Moments of the Nucleon Structure Functions and Comparison to Predictions from Lattice QCD for Q^{2}=4 GeV^{2}

We present extractions of the nucleon nonsinglet moments utilizing new precision data on the deuteron F_{2} structure function at large Bjorken-x determined via the Rosenbluth separation technique at Jefferson Lab Experimental Hall C. These new data are combined with a complementary set of data on the proton previously measured in Hall C at similar kinematics and world datasets on the proton and deuteron at lower x measured at SLAC and CERN. The new Jefferson Lab data provide coverage of the upper third of the x range, crucial for precision determination of the higher moments. In contrast to previous extractions, these moments have been corrected for nuclear effects in the deuteron using a new global fit to the deuteron and proton data. The obtained experimental moments represent an order of magnitude improvement in precision over previous extractions using high x data. Moreover, recent exciting developments in lattice QCD calculations provide a first ever comparison of these new experimental results with calculations of moments carried out at the physical pion mass, as well as a new approach that first calculates the quark distributions directly before determining moments.

Gut microbiota development of preterm infants hospitalised in intensive care units

Gut microbiome development affects infant health and postnatal physiology. The gut microbe assemblages of preterm infants have been reported to be different from that of healthy term infants. However, the patterns of ecosystem development and inter-individual differences remain poorly understood. We investigated hospitalised preterm infant gut microbiota development using 16S rRNA gene amplicons and the metabolic profiles of 268 stool samples obtained from 17 intensive care and 42 term infants to elucidate the dynamics and equilibria of the developing microbiota. Infant gut microbiota were predominated by Gram-positive cocci, Enterobacteriaceae or Bifidobacteriaceae, which showed sequential transitions to Bifidobacteriaceae-dominated microbiota. In neonatal intensive care unit preterm infants (NICU preterm infants), Staphylococcaceae abundance was higher immediately after birth than in healthy term infants, and Bifidobacteriaceae colonisation tended to be delayed. No specific NICU-cared infant enterotype-like cluster was observed, suggesting that the constrained environment only affected the pace of transition, but not infant gut microbiota equilibrium. Moreover, infants with Bifidobacteriaceae-dominated microbiota showed higher acetate concentrations and lower pH, which have been associated with host health. Our data provides an in-depth understanding of gut microbiota development in NICU preterm infants and complements earlier studies. Understanding the patterns and inter-individual differences of the preterm infant gut ecosystem is the first step towards controlling the risk of diseases in premature infants by targeting intestinal microbiota.

Disseminated Mycobacterium avium Infection Presenting with Bladder Lesions in a Patient with Interferon-γ-neutralizing Autoantibodies

A 63-year-old woman presented with a fever, eruption, and sterile pyuria. A cystoscopic examination revealed submucosal nodular lesions in the trigone of the bladder, and a biopsy specimen showed epithelioid cell granulomas in the lamina propria of the bladder. Mycobacterium avium grew in the urine culture. Other organ involvement, such as the lungs, spleen, bones, muscles, and pelvic lymph nodes, was observed on radiological examinations, and M. avium was isolated from some organ lesions. Interferon-γ-neutralizing autoantibodies were detected in the patient's serum. Therefore, the patient was diagnosed with disseminated M. avium infection, which was resolved with antimycobacterial treatment.

A Rare Monocytic Crisis of Chronic Myelogenous Leukemia Presenting with Unusual Extramedullary Manifestations and an Atypical (14;22)(q24;q11.2) Translocation in the Bone Marrow

A 48-year-old man was admitted due to marked leukocytosis. Bone marrow examinations resulted in a diagnosis of Philadelphia (Ph) chromosome-positive chronic myeloid leukemia. One month later, massive muscle and bone invasion by leukemic cells was detected. After induction chemotherapy, he complained of a headache and visual loss, which was caused by a leukemic infiltration in the central nervous system. After temporary remission in response to chemotherapy, the disease relapsed in the form of an intracranial tumor. The unusual t(14;22)(q24;q11.2) translocation of the Ph-chromosome and the significant increase in monocytes observed might have contributed to the unique and aggressive clinical course.

Iatrogenic immunodeficiency-associated Epstein-Barr virus (EBV) -negative natural killer cell lymphoproliferative disorder in a patient undergoing rheumatoid arthritis therapy

Here we present a patient with rheumatoid arthritis (RA), who was suspected to have developed malignant lymphoma during immunosuppressive therapy 5 years earlier. She temporarily achieved remission after discontinuing therapy; however, her disease worsened with remittent fever and splenomegaly. Splenic biopsy demonstrated infiltration by abnormal cells, which were positive for CD56 and T cell intracytoplasmic antigen, but negative for CD3 and Epstein-Barr virus (EBV) -encoded RNA. Cytogenetic analysis of bone marrow and lumbar spine tumor revealed common complex karyotype abnormalities. Thus, she was diagnosed with chronic natural killer cell lymphoproliferative disorder (NK-LPD) and finally died of disease progression. The most common type of LPD in methotrexate-related patients with RA is B-lymphoid LPD, whereas NK-LPD is extremely rare. Furthermore, almost all cases of NK-LPD have been reported to be positive for EBV. This is the first case report on a patient with EBV-negative NK-LPD developed during immunosuppressive therapy for RA.

[Solitary Fibrous Tumor Originating from the Visceral Pleura Presenting an Extrapleural Sign;Report of a Case]

We report a case of solitary fibrous tumor (SFT) originating from the visceral pleura, which presented an extrapleural sign on chest computed tomography (CT) and magnetic resonance imaging (MRI). A 44-year-old woman presented at our hospital for a growing mass visible in chest X-rays. Chest CT and MRI detected a 27×12 mm lesion on the intrathoracic side of the right 3rd intercostal space. The extrapleural signs strongly suggested the tumor to be chest wall origin. However, the tumor was found to be pedunculate with an umbrella-like appearance locating on the visceral pleura of the lung. Histopathological examination demonstrated SFT originating from the visceral pleura.

Emergency surgery for lung cancer with abscess formation after transbronchial biopsy

Abscess formation in lung cancer after transbronchial biopsy (TBB) is a rare complication with no standard consensus on a coping strategy or prophylaxis. We describe an instructive case of lung cancer which developed into an abscess after TBB. An 80-year-old man with poorly controlled diabetes mellitus underwent TBB for diagnosing a mass lesion in the left upper lobe. The TBB specimen confirmed a diagnosis of lung cancer, and he was scheduled for radical surgery. However, the tumour was revealed to have progressed into an enlarged abscess 24 days after TBB. Prompt use of meropenem failed to relieve the infection, hence we performed emergency left upper lobectomy. Poorly controlled diabetes mellitus was considered to be a risk for the formation of a tumour abscess after TBB. It was difficult to control the infection with conservative treatment using antibiotics; emergency surgical resection was considered to be the safest strategy for recovery.

Pulmonary micropapillary-type adenosquamous carcinoma sharing epidermal growth factor receptor mutation in adenocarcinoma and squamous cell carcinoma

Adenosquamous lung carcinoma (AdSqLC) has a worse prognosis than adenocarcinoma (ADC) or squamous cell carcinoma (SQCC). Micropapillary pattern in lung ADC is an additional poor prognostic factor. We describe a rare case of AdSqLC with epidermal growth factor receptor (EGFR) mutation in both the micropapillary‐ADC and SQCC components, showing long‐term response to gefitinib. A 60‐year‐old woman underwent right lower lobectomy for primary lung cancer. Histopathological examination demonstrated adenosquamous carcinoma comprising micropapillary‐ADC and moderately differentiated SQCC. EGFR exon 19 deletions mutation was detected in both the ADC and SQCC components. Gefitinib was administered for multiple metastatic recurrences on bilateral lung, resulting in remarkable shrinkage of visible lesions. The efficacy of gefitinib lasted for 31 months after the induction. AdSqLCs harbouring the EGFR mutation in both the ADC and SQCC components may well benefit from EGFR tyrosine kinase inhibitors, especially when they contain micropapillary‐ADC component that correlates with frequent EGFR mutations.

Mediastinal seminoma associated with multilocular thymic cyst

An asymptomatic 26-year-old man received an annual medical check-up, and chest X-ray showed a protrusion of the aortopulmonary window. Chest computed tomography (CT) revealed an anterior mediastinal tumor and cysts with thin wall and septum enhancement. The preoperative diagnosis was cystic thymoma or malignant lymphoma. We performed total resection of the tumor through a median sternotomy. The pathological findings revealed seminoma, positive for c-kit stain, and multilocular thymic cysts. Cysts were lined by normal squamous epithelium and no seminoma cells were located on their surface. So, cysts were probably secondary changes caused by seminoma cells themselves or inflammatory stimulations. No invasion to adjacent structures was seen. After the surgery, testicular ultrasound imaging and abdominal, pelvic, and cerebral CT showed no apparent tumor or enlarged lymph nodes; however, an abnormal uptake in the right mesenteric lymph node was pointed out by ¹⁸F-fluorodeoxyglucose-positron emission tomography (FDG-PET) scan. The patient received four courses of bleomycin, etoposide, and cisplatin (BEP) as adjuvant chemotherapy. Follow-up PET scan revealed no uptake in the right mesenteric lymph node. To date, no recurrence or metastasis has been identified for 16 months.

Tumor-induced Osteomalacia Caused by a Parotid Tumor

A 77-year-old man was suspected of having tumor-induced osteomalacia (TIO) because of hypophosphatemia (1.9 mg/dL) and elevated serum fibroblast growth factor 23 (FGF23) level (186.9 pg/mL). We detected a tumor in his left parotid gland, and the FGF23 level in the left external jugular vein indicated that the tumor overproduced FGF23. After the removal of the tumor, the serum FGF23 level rapidly decreased, and the serum phosphate normalized. This is the first case of TIO caused by a tumor in a parotid gland. This case indicates that the responsible tumors for TIO can be quite diverse.

Stromal micropapillary predominant lung adenocarcinoma: A rare histological phenotype with poor prognosis

An extremely rare case of stromal micropapillary predominant lung adenocarcinoma is presented in this study. A 70‐year‐old woman visited our hospital because of an abnormal shadow on chest X‐ray. Chest computed tomography revealed a nodule in the left lower lobe and a mass in the left upper lobe. She underwent an exploratory thoracotomy owing to the suspicion of advanced lung cancer. Pathological examination of the left lower lobe nodule revealed tumour cells with more than half the tumour cells showing stromal micropapillary pattern (SMP), consisting of tumour cells invading the fibrotic stroma. In general, micropapillary adenocarcinomas in the lung form an aerogenous micropapillary pattern (AMP), in which tumour cells float in alveolar spaces. Because the prognosis of SMP lung adenocarcinomas is known to be worse than that of AMP lung adenocarcinomas and have a high frequency of epidermal growth factor receptor mutations, the discrimination of SMP from AMP is important for both pathologists and clinicians.

Non-Mucinous Lepidic Predominant Adenocarcinoma Presenting with Extensive Aerogenous Spread

An extremely rare case of non-mucinous lepidic-predominant invasive adenocarcinoma (LPA) showing extensive aerogenous spread with a pneumonic presentation is reported. A 73-year-old woman was referred to our hospital because of an infiltrative shadow on chest xray. Chest computed tomography revealed extensive ground glass opacities in the right lower lobe, which was accompanied by infiltrative shadow with a pneumonic presentation. Invasive mucinous adenocarcinoma was presumed, and a partial resection of the right lower lobe was done. Histopathological examination revealed lepidic growth-predominant invasive adenocarcinoma with Clara type tumor cells, and there were innumerable aerogenous metastases also consisting of Clara cells. Because Alcian Blue and periodic acid-Schiff staining disclosed no mucus, the tumor was diagnosed as a non-mucinous LPA. The patient showed a poor response to 5 courses of pemetrexed, and she died one year after the diagnosis due to cancer progression. Nonmucinous LPA showed a rare presentation characterized by extensive aerogenous spread followed by a poor prognosis.

Infant formula with galacto-oligosaccharides (OM55N) stimulates the growth of indigenous bifidobacteria in healthy term infants

The objective of the study was to investigate whether an infant formula supplemented with galacto-oligosaccharides (GOS; OM55N) was able to stimulate the growth of indigenous bifidobacteria and to establish microbiota similar to that of breastfed infants. A randomised, double-blind, placebo-controlled trial was performed using 35 healthy term infants (31-54 days of age; 42±6 days) to determine whether infant formula with 0.3 g/dl GOS (OM55N) stimulated the growth of bifidobacteria in the infants’ guts. At the trial onset and 2 weeks after, the infants’ faecal samples were examined for microbiota composition (bacterial abundance and α-diversity) and faecal characteristics. Among the 35 infants, 5 were withdrawn and 8 were excluded from the final evaluation before breaking the blinding since the indigenous bifidobacteria were not detected at the trial onset. After 2 weeks, the abundance of Bifidobacteriaceae was significantly increased in the GOS feeding group compared to the control (+11.6±24.1% vs -3.9±13.0%; P=0.043). The Shannon index, which accounts for both abundance and evenness of the present species, was significantly decreased with GOS supplementation (-0.1±0.4 vs +0.4±0.4; P=0.014). Faecal characteristics such as pH and organic acids were similar in both groups, with no statistical differences. No adverse side effects related to the formula consumption were reported. Although the concentration of GOS was relatively low, the infant formula with GOS increased the abundance of bifidobacteria and resulted in a reduced α-diversity of the microbiota.

Alveolar-filling growth pattern of sarcomatoid malignant pleural mesothelioma

A case of sarcomatoid malignant pleural mesothelioma showing extremely rare growth pattern is described. A 63-year-old man presented to our hospital with left pleural effusion. A computed tomography (CT) scan of the chest showed diffusely thickened left visceral and parietal pleura associated with intermingled pulmonary infiltrative shadowing. Biopsy of the pleura under general anaesthesia confirmed the diagnosis of sarcomatoid malignant pleural mesothelioma. The patient underwent left extra-pleural pneumonectomy. Histopathologically, the sarcomatoid spindle tumour cells changed their morphology to polygonal cells in the pulmonary parenchyma and grew upwards, filling the alveolar space without the destruction of its septa, showing an alveolar-filling growth pattern. The current report indicates a case of sarcomatoid pleural mesothelioma that shows an alveolar-filling growth pattern, despite having not been thoroughly categorized in the World Health Organization (WHO) classification.

Locally infiltrative inflammatory fibroid polyp of the ileum: report of a case showing transmural proliferation

Morphologically, an inflammatory fibroid polyp (IFP) is usually centred in the submucosa. Extension of an IFP to the subserosa with destruction of the muscularis propria is exceedingly rare. Herein, we describe a 70-year-old woman who presented with right lower abdominal pain but was finally diagnosed with an IFP. Contrast-enhanced computed tomography revealed a target-like structure with a hypovascular mass at the leading edge, which was consistent with intussusception due to a tumour. Following surgery, the resected specimen displayed a mass measuring 4 × 3 × 3 cm that was protruding into the lumen. Microscopically, the mass was centred in the submucosa, extending up to the mucosal surface and down to the subserosa and serosa. The muscularis mucosae and muscularis propria were destroyed focally. A PDGFRA gene mutation in exon 2 (1837_1851 del) that was found in this case, as well as a highly infiltrative growth pattern, strongly supported the neoplastic nature of IFP.

Visualization of sphingolipids and phospholipids in the fundic gland mucosa of human stomach using imaging mass spectrometry

AIM: To analyze the lipid distribution in gastric mucosae.

METHODS: Imaging mass spectrometry (MS) is a useful tool to survey the distribution of biomolecules in surgical specimens. Here we used the imaging MS apparatus named iMScope to identify the dominant molecules present in the human gastric mucosa near the fundic glands. Five gastric specimens were subjected to iMScope analysis. These specimens were also analyzed by immunohistochemistry using MUC5AC, H(+)-K(+)-ATPaseβ Claudin18 antibodies.

RESULTS: Three major molecules with m/z 725.5, 780.5, and 782.5 detected in the gastric mucosa were identified as sphingomyelin (SM) (d18:1/16:0), phosphatidylcholine (PC) (16:0/18:2), and PC (16:0/18:1), respectively, through MS/MS analyses. Using immunohistological staining, SM (d18:1/16:0) signals were mainly co-localized with the foveolar epithelium marker MUC5AC. In contrast, PC (16:0/18:2) signals were observed in the region testing positive for the fundic gland marker H(+)-K(+)-ATPaseβ. PC (16:0/18:1) signals were uniformly distributed throughout the mucosa.

CONCLUSION: Our basic data will contribute to the studies of lipid species in physical and pathological conditions of the human stomach.

Deposition of elafin in the involved vascular wall of neutrophil-mediated cutaneous vasculitis

BACKGROUND

Neutrophil elastase plays an important role in skin inflammation induced by neutrophil infiltration. Elafin is an inducible elastase inhibitor expressed by keratinocytes, and is known to be involved in pathogenesis of neutrophilic skin disorders such as psoriasis.

METHODS

Immunohistochemical studies of elafin expression in the cases of vasculitis were performed. Induction of elafin expression in cultured vascular cells and its effect on neutrophil migration were studied in vitro.

RESULTS

A positive immunoreactivity was detected in polyarteritis nodosa, giant cell arteritis and Schönlein-Henoch purpura, but no immunoreactivity was found in Churg-Strauss syndrome. Elafin expression in cultured venous endothelial cells and arterial smooth muscle cells was undetectable, but induced by interleukin-1β (IL-1β) and IL-8. Elafin inhibited the elastin peptide-induced neutrophil chemotaxis at the concentration of 10(-8) -10(-5) mol/L.

CONCLUSION

Elafin deposition induced by cytokines (IL-1β or IL-8) will be an important regulator for the progress of leucocytoclastic vasculitis by functioning as an inhibitor for neutrophil chemotaxis as well as for vascular elastin degradation.

A case of successful detection of disseminated gastrointestinal stromal tumors by ascites smear cytology using cell block preparation with DOG1 immunostaining

Cytological features of gastrointestinal stromal tumors (GISTs) have been reported, especially regarding fine-needle aspiration cytology, including immunostaining for c-kit and DOG1. Meanwhile, cytological findings of GISTs on ascites cytology have rarely been reported, which may be owing to the rare appearance of GIST tumor cells in ascites. Herein, we present a 66-year-old woman who had disseminated GISTs in the abdomen. The GIST tumor cells appeared sparsely in the ascites smear cytology using ascites obtained at the time of autopsy. Even when widespread intra-abdominal dissemination takes place, GISTs may be hard to detect in ascites smear cytology, based on the experience of this case. However, immunohistochemistry of DOG1 using a cell block preparation was found to clearly visualize the GIST tumor cells, although they were sparsely present. Immunostaining of c-kit did not provide as clear an identification of the tumor cells as DOG1 did. When suspicious about GISTs, it is wise to prepare a cell block to make it possible to visualize the tumor cells immunohistochemically.

Metaplastic thymoma with myasthenia gravis presumably caused by an accumulation of intratumoral immature T cells: a case report

Among human neoplasms, thymomas are well known for their association with paraneoplastic autoimmune diseases such as myasthenia gravis. However, regarding rare metaplastic thymoma, only one case of an association with myasthenia gravis has been reported. Here, we present the second case of a 44-year-old woman with metaplastic thymoma associated with myasthenia gravis. In metaplastic thymoma, intratumoral terminal deoxynucleotidyl transferase-positive T-cells (immature T-cells) are generally scarce, while they were abundant in the present case. We believe that these immature T-cells could be related to the occurrence of myasthenia gravis.

A case of matrix-producing metaplastic carcinoma of the breast exhibiting similarities to pleomorphic adenoma on fine-needle aspiration cytology

The distinction between matrix-producing metaplastic carcinoma (MPMC) and pleomorphic adenoma (PA) is sometimes unclear in breast pathology, especially on core needle biopsy. Herein, we presented a 66-year-old woman with MPMC of the breast that looked like PA on fine-needle aspiration cytology (FNAC). On FNAC, the appearance of abundant myxoid matrix along with cellular clusters composed of monotonous cellular populations looked like salivary PA, which we were familiar with owing to the frequency in routine pathological practice. Thus, the possibility of breast PA, the counterpart of salivary PA, was considered. However, the tumor location was different from where breast PA frequently occurs, i.e. the retroareolar region. Therefore, we eliminated the possibility of breast PA and avoided the erroneous cytological diagnosis. It is should be kept in mind that MPMC can look like PA on FNAC.

KRAS mutation-positive bronchial surface epithelium (BSE)-type lung adenocarcinoma with strong expression of TTF-1: a case providing a further insight as for the role of TTF-1 in the oncogenesis

Bronchial surface epithelium (BSE)-type lung adenocarcinoma is a subtype of non-terminal respiratory unit (TRU)-type lung adenocarcinoma originating in the bronchial surface epithelium. However, there are few known cases of BSE-type adenocarcinoma with marked expression of thyroid transcription factor-1 (TTF-1). This paper describes a very rare case of KRAS mutation-positive BSE-type adenocarcinoma that exhibited strong expression of TTF-1 that was putatively involved in oncogenesis. An 84-year-old woman, a never smoker, was referred to our hospital because of an abnormal chest radiograph. Chest computed tomography (CT) showed a solid mass lesion, 15 mm × 10 mm, with a relatively smooth margin in the left upper lobe. The patient underwent partial resection of the left upper lobe for strongly suspected lung cancer with a clinical stage of cT1aN0M0. Histopathological findings showed continuous migration of papillary, hyperplastic, atypical columnar tumor cells originating from normal bronchial surface epithelium, leading to a diagnosis of BSE-type adenocarcinoma. TTF-1 was strongly expressed in almost 100% of the tumor cells, which tested positive for the KRAS mutation. TTF-1 has recently attracted attention as an oncogene, and it is purportedly involved in the carcinogenesis and survival of lung adenocarcinoma cells. There is typically an inverse correlation between the respective expressions of KRAS and TTF-1, but in the present study, they appeared simultaneously and were both putatively involved as oncogenic driver alterations. This case is important in that it sheds some light on the largely unknown pathogenic mechanism of BSE-type adenocarcinoma.

Methotrexate-associated lymphoproliferative disorder presenting as extranodal NK/T-cell lymphoma arising in the lungs

Patients having rheumatoid arthritis (RA) treated with methotrexate (MTX) are at an increased risk of developing lymphoproliferative disorder (LPD). Epstein-Barr virus (EBV) sometimes contributes to the development of MTX-associated LPD. Herein, we report the case of a 64-year-old Japanese woman with RA who showed complications of EBV-positive MTX-associated LPD. This case is exceedingly rare in that the LPD was confined to the lungs and its subclassification was extranodal NK/T-cell lymphoma. Only four cases of extranodal NK/T-cell lymphoma in the setting of MTX-associated LPD have ever been reported in the English language literature, only one of which was an extranasal NK/T-cell lymphoma, similar to our case. Extranasal NK/T-cell lymphomas show more aggressive behavior than nasal NK/T-cell lymphomas, possibly reflected by the considerable re-exacerbation of the lesions in only two months after the cessation of MTX in our case. However, the SMILE regimen (steroid, methotrexate, ifosfamide, l-asparaginase, and etoposide) was able to suppress tumor growth in this case.

Palatine tonsillar metastasis of a small pulmonary adenocarcinoma showing an invasive micropapillary carcinoma pattern and Pagetoid spread at the tonsil: a case suggesting retrograde lymphatic metastasis from bulky lymph node metastases of the neck

Metastasis rarely occurs in the palatine tonsils. Among primary pulmonary carcinoma subtypes, small cell carcinoma more frequently metastasizes to this site. Herein, we present an exceedingly rare case of a small pulmonary adenocarcinoma that metastasized to the cervical lymph nodes and the right palatine tonsil in a 62-year-old man. In spite of the small size of the primary site, such extensive metastasis may have occurred because of the invasive micropapillary carcinoma pattern seen in the metastatic sites. The manner of metastasis to the palatine tonsil was considered retrograde lymphatic metastasis originating from carcinoma cells in the cervical lymph nodes. Furthermore, Pagetoid spread was observed at the palatine tonsil. Although there have been only a few cases showing retrograde lymphatic metastasis and Pagetoid spread at the metastatic site, we should be careful when speculating about the primary site based on such metastatic sites, especially when dealing with a biopsy sample exhibiting Pagetoid spread.

Perivascular epithelioid cell tumor of the uterine cervix identified on a conventional cervical smear

Perivascular epithelioid cell tumors (PEComas) most frequently involve the uterus, particularly the uterine corpus and very occasionally the cervix. One case of PEComa identified using a conventional cervical smear has previously been documented. Herein, we present the second such case. The patient was a 51-year-old woman with abnormal genital tract bleeding. Samples collected for conventional cervical smears were submitted for cytopathological examination, which revealed discohesive monotonous tumor cells showing epithelioid morphology, ample cytoplasm that was pale to weakly eosinophilic, and mildly enlarged nuclei. The cytopathological features were well correlated with histopathological findings. Upon immunohistochemistry, the tumor cells were positive for both melanocytic and smooth muscle markers. Based on these findings, PEComa was diagnosed. Subsequently, a total hysterectomy with bilateral salpingo-oophorectomy was performed, revealing that the tumor (28 × 22 × 12 mm) was located at the superficial part of the endocervix. We propose that the cytopathological findings described herein can guide the diagnosis of PEComa, even though this tumor is rare.

Intraductal tubulopapillary neoplasm of the pancreas suspected by endoscopic ultrasonography-fine-needle aspiration cytology: Report of a case confirmed by surgical specimen histology

Intraductal tubulopapillary neoplasm (ITPN) of the pancreas is rare compared with intraductal papillary mucinous neoplasm (IPMN). These entities are distinguished by endoscopic ultrasonography (EUS)-fine-needle aspiration cytology (FNAC) on the basis of mucin production and the presence of a tubular or papillary growth pattern. In addition, there are several tumor types that should be distinguished from ITPN, such as solid pseudopapillary neoplasm, acinar cell carcinoma, and pancreatic neuroendocrine tumor. Herein, a case of an 80-year-old man with ITPN, which was suspected based on EUS-FNAC findings at the time of review and confirmed by histological examination of the surgically resected specimen, has been presented. There have only been three reported cases that included the cytology of ITPN in the English language literature, all of which propose diagnostic features of ITPN based on cytological specimens. Here, a previously undescribed diagnostic feature of ITPN revealed by EUS-FNAC--tubules in contact with fibrovascular structures--correlated well with the histological findings of the surgically resected specimen, has been shown.

A case of Miller Fisher syndrome during preoperative chemotherapy for breast cancer

A 53-year-old woman with breast cancer received FEC treatment (5FU: 500 mg/m(2), epirubicin: 100 mg/m(2), and cyclophosphamide: 500 mg/m(2)) every 3 weeks as preoperative chemotherapy. Fifteen days after her third cycle of FEC, she developed a cold. Diplopia occurred 4 days after developing the cold, and progressive paresthesia of the hands and weakness of the limbs occurred. She had ophthalmoplegia, ataxia, and are flexia and was diagnosed with Miller Fisher Syndrome (MFS). The cause of MFS during chemotherapy is believed to be caused by an immunological response to infection, or drug neurotoxicity. In our case, since the patient underwent an antecedent upper respiratory infection in the period of myelosuppression, her MFS was probably induced by the immunoreaction associated with this infection. Our patient underwent intravenous immunoglobulin therapy. After initiation of the treatment, her neurological symptoms improved, then, she received a fourth cycle of FEC and her remaining neurological symptoms did not worsen. Thus, we report a rare case of MFS developed in immunosuppression by chemotherapy and remind physicians of the alarming triad of MFS symptoms.

Refractory status epilepticus, serious rhabdomyolysis, acute liver injury, and pancytopenia after a massive intake of ethyl methanesulfonate: a case report

Ethyl methanesulfonate is a mutagenic, alkylating agent and considered harmful to humans at levels greater than a certain threshold; however, the toxicity at high doses remains unclear. We report a case of a Japanese man who presented with status epilepticus, rhabdomyolysis, pancytopenia, and hair loss after accidental ingestion of a massive amount of ethyl methanesulfonate. The patient completely recovered with critical care, including multiple antiepileptic drugs, renal replacement therapy, blood transfusion, granulocyte colony-stimulating factor therapy, and antibacterial/fungal prophylaxis. The case indicates that ethyl methanesulfonate causes neurotoxicity, hepatotoxicity, hematotoxicity, and renal toxicity, which can be successfully treated with appropriate palliative therapies.

Cysts in angiomyolipoma with epithelial cysts may be consisted of entrapped and dilated renal tubules: report of a case with additional immunohistochemical evidence to the pre-existing literature

Angiomyolipoma with epithelial cysts (AMLEC) is a distinctive variant of angiomyolipoma characterized by grossly apparent epithelial cysts and a cellular, müllerian-like subepithelial stroma. Some authors suspect that the epithelial cysts mainly represent dilated entrapped native renal collecting duct epithelium, while other authors think that they represented true epithelial differentiation of the AML. Recently, it has been reported that obvious immunolabeling of melanocytic markers such as Melan A and HMB45, which are often immunolabeled in classical angiomyolipoma, are present in epithelial cysts in cases of AMLEC. Here, we report the case of a 43-year-old Japanese woman with AMLEC, and attempt to elucidate the significance of melanocytic marker immunolabeling in the cyst's epithelium. In the present case, Melan A was labeled in the cyst's epithelium, and was thought to reflect its labeling in renal tubules existing in the renal parenchyma outside the tumor. This finding may indicate that the cyst epithelium is derived from entrapped renal tubules inside the AML. Non-immunolabeling of the estrogen and progesterone receptors in the cyst epithelium may also suggest that the cyst epithelium is not neoplastic, in contrast to their labeling in neoplastic cells existing in cyst wall. Further examination, such as molecular analysis, is needed to determine whether these epithelial cysts is neoplastic or non-neoplastic.

Rhabdoid variant of urothelial carcinoma of the urinary bladder: a case report with emphasis on immunohistochemical analysis regarding the formation of rhabdoid morphology

Various histological variants of urothelial carcinoma (UC) have been described. They are associated with different clinical outcomes and/or therapeutic approaches; in addition, recognition of these histological variants is also important in preventing diagnostic misinterpretations. Histological variants based on cytoplasmic features, such as plasmacytoid, rhabdoid, clear-cell, and lipoid-rich variants, have been described in invasive UC. Herein, we report an exceedingly rare case of a rhabdoid variant of UC arising in the urinary bladder of a 61-year-old man. Including UC, the presence of rhabdoid cells has been described in various types of malignant tumors. These tumors are regarded as more aggressive neoplasms than those without rhabdoid cells. It has been previously found that non-degraded aggregation of intermediate filaments and membrane proteins conjugated with ubiquitin and p62 is a noticeable finding in the formation of rhabdoid morphology. We have validated the existence of this mechanism in a rhabdoid variant of UC by extensive immunohistochemical analysis.

Fibroblast growth factor receptor 1 (FGFR1) expression in phosphaturic mesenchymal tumors

Phosphaturic mesenchymal tumor (PMT) has been elucidated as a cause of tumor-induced osteomalacia (TIO) associated with mesenchymal neoplasm. TIO is associated with the production of phosphatonins, such as fibroblast growth factor 23 (FGF23), which participate in phosphate homeostasis. Fibroblast growth factor receptor 1 (FGFR1) is a known receptor of FGF23, and it was recently found that the fibronectin 1 (FN1)-FGFR1 fusion gene is present in 60% of PMT cases. Immunohistochemical evaluation of FGFR1 expression in PMT has not been reported till date. We analyzed 11 cases of PMT in this study and found that 36% of cases (4/11 cases) exhibited cytoplasmic and membranous staining with strong intensity, and 64% of cases (7/11 cases) exhibited cytoplasmic dot-like staining with moderate to weak intensity. The aforementioned 36% of cases may reflect the presence of the FN1-FGFR1 fusion gene, as the FN1 promoter enhances FGFR1 expression. Although FGFR1 signaling increases FGF23 expression in an autocrine/paracrine loop, FGF23 serum level does not correlate with FGFR1 membranous expression (staining with strong intensity). Thus, we speculate that important factors other than FGFR1 are involved in the tumor biology of PMTs overexpressing FGF23.

Possibility of D2-40 as a diagnostic and tumor differentiation-suggestive marker for some of phosphaturic mesenchymal tumors

Phosphaturic mesenchymal tumor (PMT) has been established as a tumor that causes tumor-induced osteomalacia (TIO) associated with mesenchymal neoplasm. Its lineage of differentiation has not been elucidated. Previously, the presence of lymphatic vessels inside PMTs has been documented using an anti-podoplanin antibody; the tumor cells of PMTs were reported to not react with it. In this study of 14 cases of PMTs, we used immunohistochemistry of D2-40, a relatively specific lymphatic endothelial marker, to see if they stained PMTs or not, with particular interest in its reaction with microcystic structures containing lymph-like fluid. We report that most of the PMTs (12 out of 14 cases; 86%) were immunostained by D2-40 in their tumor cells; D2-40-positive lymphatic vessels inside the tumor were also observed. We used a proportion score (0-4+), an intensity score (0-3+), and a total score (the sum of the proportion score and the intensity score) to quantitate our results. We report that 50% of cases (7 out of 14 cases) had a total score ≥ 4+; immunostaining of D2-40 in cases with a total score ≥ 4+ was easy to observe at a glance. Most of the tumor cells lining the microcystic structures were immunostained with D2-40. Thus, D2-40 could be a useful diagnostic marker of PMTs and it might also indicate that PMTs take a lymphatic endothelial immunophenotype.

Two cases of matrix-producing carcinoma showing chondromyxoid matrix in cytological specimens

Matrix-producing carcinoma (MPC) is extremely rare. Limited reports have described the cytological aspects of MPC. Herein, we present 2 cases of MPC, both of which showed ring-enhancement on magnetic resonance imaging (MRI) and chondromyxoid matrix on cytological specimens. In these cases, the diagnosis of MPC was preoperatively suspected. Recognizing extracellular matrix as chondromyxoid matrix on the cytological specimen is important in making a distinction between MPC and mucinous carcinoma. They share some features on cytology and MRI (ring-enhancement) but have different prognoses and involve different approaches for obtaining histological specimens for neoadjuvant therapy. The reason for the different approaches for obtaining the histological specimens is that tumor cells usually distribute peripherally in MPC in contrast to the relatively uniform distribution of mucinous carcinoma. Therefore, it would be helpful if the diagnosis of MPC can be suspected by examination of the cytological specimen.

Primary leiomyosarcoma of the breast with prominent osteoclastic giant cells: A case expressing receptor activator of NF-κB ligand (RANKL)

Primary sarcomas of the breast are rare, accounting for less than 1% of all breast neoplasms. Leiomyosarcoma is one of the least common breast sarcoma subtypes, and less than 50 cases of primary breast leiomyosarcomas have been reported in the English literature. In other types of leiomyosarcoma, osteoclastic giant cells (OGCs) are occasionally admixed with tumor cells; however, this is rarely seen in primary breast leiomyosarcoma. We herein present the case of a 50-year-old woman with OGC-containing primary breast leiomyosarcoma whose tumor cells showed positive immunostaining for receptor activator of NF-κB ligand (RANKL). The presence of OGCs in tumors generally indicates tumor aggressiveness. This is true for leiomyosarcoma of the soft tissue and might be true for leiomyosarcoma of primary breast origin. Regarding RANKL expression, in giant cell tumor of bone (GCTB) in which OGCs expressing RANK were abundant, tumor cells are known for expressing RANKL. Therapy targeting RANKL decreases the number of tumor cells of GCTB. Our findings are clinically relevant as they indicate that RANKL expression should be investigated in various tumors containing OGCs. This might lead to the development of future molecule-targeted therapy.

ALK-rearranged squamous cell carcinoma of the lung

The fusion gene echinoderm microtubule-associated protein-like 4 (EML4)–anaplastic lymphoma kinase (ALK) is identified in approximately 5% of non-small-cell lung cancer patients. A rare case of ALK-positive squamous cell carcinoma of the lung is reported. A 60-year-old man, an ex-smoker with a 720-packs-per-year tobacco smoking history, presented with a mass lesion in the upper lobe of the left lung on chest computed tomography. Transbronchial biopsy of the mass confirmed a diagnosis of lung squamous cell carcinoma, and it was proven to have ALK rearrangement by fluorescent in situ hybridization. The patient underwent left upper lobectomy. Hematoxylin and eosin staining of the surgical specimen demonstrated the typical morphology of pure squamous cell carcinoma. The patient has been advised to attend regular check-ups for postoperative recurrence. ALK testing and subsequent ALK-targeted treatment can be a possible option in cases of postoperative recurrence.

Robust quantitative assessments of cytosine modifications and changes in the expressions of related enzymes in gastric cancer

BACKGROUND

The rediscovery of 5-hydroxymethylcytosine, the ten-eleven translocation (TET) family, thymine-DNA glycosylase (TDG) and isocitrate dehydrogenase (IDH) have opened new avenues in the study of DNA demethylation pathways in gastric cancer (GC). We performed a comprehensive and robust analysis of these genes and modified cytosines in gastric cancer.

METHODS

Liquid chromatography mass spectrometry/mass spectrometry (LC-MS/MS) was used to assess 5-methyldeoxycytidine (5-mC), 5-hydroxymethyldeoxycytidine (5-hmC), 5-formyldeoxycytidine (5-fC) and 5-carboxyldeoxycytidine (5-caC) quantitatively in tumorous and non-tumorous regions of GCs; [D2]-5-hmC was used as an internal standard. Expression levels of the genes TET1, TET2, TET3, TDG, IDH1 and IDH2 were measured using a real-time reverse transcription polymerase chain reaction (RT-PCR) and were compared to the clinical attributes of each case. Using HEK293T cells the effects of introducing plasmids containing full-length TET1, TET2, and TET3 and 7 variants of the TET2 catalytic domain were evaluated in terms of their effect on cytosine demethylation.

RESULTS

LC-MS/MS showed that 5-hmC was significantly decreased in tumorous portions. 5-mC was also moderately decreased in tumors, while 5-fC and 5-caC were barely detectable. The expressions of TET1, TET2, TET3, TDG and IDH2, but not IDH1, were notably decreased in GCs, compared with the adjacent non-tumor portion. TET1 expression and the 5-hmC levels determined using LC-MS/MS had a significantly positive correlation and TET1 protein had a greater effect on the increase in 5-hmC than TET2 and TET3 in HEK293T cells.

CONCLUSIONS

The loss of 5-hmC and the down-regulation of TET1-3, TDG and IDH2 were found in GCs. The loss of 5-hmC in GCs was mainly correlated with the down-regulation of TET1.

Urothelial carcinoma with oncocytic features: an extremely rare case presenting a diagnostic challenge in urine cytology

Recognizing histological variants in urothelial carcinoma (UC) is important because some may be associated with different clinical outcomes and/or therapeutic approaches; being aware of unusual histological variants may also be crucial in preventing diagnostic misinterpretations. Histological variants based on cytoplasmic features, such as clear-cell, plasmacytoid, rhabdoid, and lipoid-rich variants, are described in invasive UC; however, these cytoplasmic features are not formally defined and not usually encountered in non-invasive UC. Oncocytic cytoplasm has not been well described in either invasive or non-invasive UC. Herein, we report an exceedingly rare case of UC with oncocytic features arising in the right renal pelvis, which presented a diagnostic challenge in urine cytology due to the relatively low nuclear-to-cytoplasmic ratio; however, it could definitively be diagnosed using histological specimens. UC diagnosis is based on the presence of papillary architecture and widespread p53 nuclear accumulation, suggesting malignancy. An oncocytic tumor is generally considered to be not actively dividing, as shown by the low Ki-67 labeling index in this case. In spite of the low proliferative activity, the possibility of intravesicle recurrence (IVR) should be considered since positive preoperative cytology of upper tract UC is a risk factor for IVR after nephroureterectomy.

CD56 may be a more useful immunohistochemical marker than somatostatin receptor 2A for the diagnosis of phosphaturic mesenchymal tumors

Phosphaturic mesenchymal tumors (PMTs) are the most typical cause of tumor-induced osteomalacia (TIO) associated with mesenchymal neoplasms. Specifically, TIO is attributed to the production of phosphatonins, such as fibroblast growth factor 23 (FGF23), participating in the homeostasis of phosphate. Although immunohistochemistry (IHC) for FGF23 showed characteristic positive staining in PMTs, FGF23 antibodies that can be used for the reliable diagnosis of PMTs are hard to obtain in common pathology laboratories. Somatostatin receptor 2A (SSTR2A) has been previously proposed as an alternatively useful marker for the diagnosis of PMTs. However, SSTR2A is not commonly utilized in pathological laboratories. The CD56 marker is a useful alternative that is comparable to SSTR2A and is similar considering the sensitivity. Even in cases of PMTs originating in the bones, ethylenediaminetetraacetic acid-based decalcification for tissue processing does not seem to affect the IHC of CD56. As CD56 immunopositivity in mesenchymal tumors is limited, it also has some degree of specificity for PMTs. Thus, when PMTs are suspected, the use of CD56 is recommended.

Granulomatous inflammation of pulmonary squamous cell carcinoma: a rare phenomenon

Some neoplasms are associated with granulomatous inflammation. Granuloma formation in tumor tissue is caused by the cytokines derived from either the main tumor or other cells surrounding the tumor. In other instances, granulomatous inflammation is observed in the lymph nodes draining a tumor. This has been recognized as a sarcoid-like reaction. Herein, we report of a 75-year-old man with pulmonary squamous cell carcinoma (SCC), where granulomatous inflammation was observed extensively at the primary site. The carcinoma seemed to partly regress. In the regressing area, tumor cell debris was surrounded by granuloma. In contrast, no granuloma was identified in the dissected regional lymph nodes. To the best of our knowledge, such a case of SCC had not been described thus far. More case studies are required to determine whether tumor-related granuloma is the main cause of regression or whether it is just a secondary phenomenon caused by the attack and destruction of the tumor by lymphocytes.

A SMARCB1-deficient vulvar neoplasm with prominent myxoid stroma: report of a case showing ERG and FLI1 expression

In the vulvar region, epithelioid sarcoma (ES) is the most frequent SMARCB1-deficient neoplasm, followed by myoepithelial carcinoma (MC). Previous studies have demonstrated that some SMARCB1-deficient vulvar neoplasms cannot be classified as either ES or MC. Herein, we report of a 42-year-old woman with a SMARCB1-deficient neoplasm with prominent myxoid stroma in the vulva. It contained both epithelioid and spindled tumor cells, both of which showed vimentin and EMA expression. Although other markers useful for the differential diagnosis among SMARCB1-deficient tumors were negative, this tumor displayed characteristic expression of ERG and FLI1. As there are no reliable data regarding expression of ERG and FLI1 in MC, which are demonstrated to be often expressed in ES, further classification of cases such as the one reported here requires reliable data regarding their expression status in MC.

Transition between morule-like and solid components may occur in solid-predominant adenocarcinoma of the lung: report of 2 cases with EGFR and KRAS mutations

A limited number of pulmonary adenocarcinoma cases with morule-like components have been described to date, and the most frequent histological subtype is papillary-predominant adenocarcinoma. Occasionally, this type of adenocarcinoma is associated with solid-predominant adenocarcinoma. EGFR mutations are predominant in adenocarcinoma with morule-like components, followed by ALK rearrangements. Herein, we present 2 cases of solid-predominant adenocarcinoma with morule-like components harboring either an EGFR or KRAS mutation. This KRAS-mutant case is the first to be associated with morule-like components, to the best of our knowledge. Both cases showed transition between micropapillary and morule-like components. Transition between morule-like and solid components was also observed in both cases. Although a few cases of solid-predominant adenocarcinoma have been shown to harbor morule-like components, this type of transition has not been previously well described. We surmised that the solid components of some EGFR-mutant adenocarcinomas might be derived from morule-like components.

Gastric carcinoma with an invasive micropapillary carcinoma component showing HER2 gene amplification and CD10 expression: a case report and review of the literature

An 81-year-old man was referred to our hospital because gastric cancer was detected on screening esophagogastroduodenoscopy. Surgical resection of the tumor was performed. It was 25 × 20 mm in size and swollen lymph nodes were present nearby. Lymphadenectomy was also performed. Histopathologically, the tumor reached the proper muscle layer via venous invasion. There were three components that constituted the tumor, that is, 40% of mass was invasive micropapillary carcinoma (IMPC), 40% was papillary adenocarcinoma and 20% tubular adenocarcinoma. Vascular invasion was prominent. Immunohistochemistry revealed that the tumor showed an entirely intestinal mucin phenotype, being positive only for CD10 and negative for MUC2, MUC5AC, and MUC6. HER2 staining score ranged from 2+ to 3+, depending on the components described above. HER2 gene amplification was present in all the components according to dual-color in situ hybridization. The metastatic lymph nodes were similar to the primary site in morphology and immunohistochemistry, but HER2 amplification was higher in the lymph nodes. The IMPC component with HER2 amplification is rarely seen and its positivity for CD10 is an unexpected finding for gastric IMPC. Hence, this is a highly unusual case judging by the literature; further studies are needed to clarify the nature of gastric IMPC.

Mediastinal mature teratoma with complete gastrointestinal and bronchial walls

An extremely rare case of anterior mediastinal mature teratoma with almost complete gastrointestinal and bronchial walls is described. A 65-year-old woman presented with left precordial pain. Chest computed tomography showed a huge anterior mediastinal tumor, 15 cm × 21 cm, occupying the left thoracic cavity. Post-resection histopathological examination confirmed the diagnosis of mature teratoma and demonstrated almost complete gastrointestinal and bronchial walls. Although mature teratomas of the ovary and sacrococcygeal area are known to rarely contain organoid structures with various degrees of differentiation, this is the first case of an anterior mediastinal mature teratoma that contained well-developed organoid structures.