Shogo Tajima

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

BackgroundThe 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.MethodsLiquid 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.ResultsLC-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.ConclusionsThe 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.

Neuroendocrine tumor, well differentiated, of the breast: a relatively high-grade case in the histological subtype.

Primary neuroendocrine carcinoma of the breast is a rare entity, comprising <1% of breast carcinomas. Described here is the case of a 78-year-old woman who developed an invasive tumor in the left breast measuring 2.0 cm x 1.5 cm x 1.2 cm. The tumor was composed of only endocrine elements in the invasive part. It infiltrated in a nested fashion with no tubular formation. Intraductal components were present both inside and outside of the invasive portion. Almost all carcinoma cells consisting of invasive and intraductal parts were positive for synaptophysin and neuron-specific enolase. According to the World Health Organization classification 2012, this tumor was subclassified as neuroendocrine tumor, well-differentiated. Among the subgroup, this tumor was relatively high-grade because it was grade 3 tumor with a few mitotic figures. Vascular and lymphatic permeation and lymph node metastases were noted. In the lymph nodes, the morphology of the tumor was similar to the primary site. No distant metastasis and no relapse was seen for one year after surgery. The prognosis of neuroendocrine carcinomas is thought to be worse than invasive mammary carcinomas, not otherwise specified. Therefore, immunohistochemistry for neuroendocrine markers is important in the routine practice to prevent overlooking neuroendocrine carcinomas.

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.

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. Diagn. Cytopathol. 2015;43:1003–1006.

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.

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.

Pleomorphic leiomyosarcoma with a dedifferentiation-like appearance in the kidney: case report and literature review

Although primary leiomyosarcoma of the kidney is extremely rare, it is the most common sarcoma of the kidney. Leiomyosarcoma with a large pleomorphic component is designated as pleomorphic leiomyosarcoma. The pleomorphic component is usually similar to undifferentiated high-grade pleomorphic sarcoma, although it variably expresses smooth muscle markers on immunohistochemistry. In the few reported cases of pleomorphic leiomyosarcoma of the kidney, cases with the pleomorphic component showing distinct nodularity similar to dedifferentiated leiomyosarcoma have not been described, to the best of our knowledge. Herein, we present a case of a 49-year-old woman with pleomorphic leiomyosarcoma in the kidney showing distinct nodularity of smooth muscle marker-expressing pleomorphic cells within a background of classic leiomyosarcoma. Along with the classification as a pleomorphic leiomyosarcoma, suggesting aggressive clinical behavior, the renal origin itself might also be a predictor of poor prognosis, as shown in a previous study. This case also involved concomitant distant metastases, already present during the initial detection of the renal tumor.

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

Abstract 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.

A signet-ring cell melanoma arising from a medium-sized congenital melanocytic nevus in an adult: A case report and literature review

Patients with congenital nevus, especially giant congenital melanocytic nevus (CMN) measuring >20 cm, are known to be at elevated risk of developing melanomas, especially during the first and second decades of life. Melanomas rarely develop in patients with small and medium‐sized CMNs, but if they do, they occur during the fourth and fifth decades of life. We present a case of a rapidly enlarging signet‐ring cell melanoma (over 3 months) that arose from a medium‐sized CMN in a 57‐year‐old Japanese man. Only 11 other cases of signet‐ring cell melanomas at the primary site have been reported. On the basis of morphology alone, it is difficult to diagnose a nodule appearing in a CMN as a signet‐ring cell melanoma, because even a benign melanocytic nevus can appear as signet‐ring cell morphology. Moreover, a rapidly growing proliferative nodule (PN) more often develops in a CMN than melanoma; PNs may at times exhibit enough atypia to be comparable to melanomas. In our case, loss of p16 expression in the melanoma distinguished it from the nevus cells and was helpful in making the correct diagnosis. Clinical information, such as the patients age, was also useful in establishing the diagnosis.

Acquired cystic disease‐associated renal cell carcinoma with a focal sarcomatoid component: Report of a case showing more pronounced polysomy of chromosomes 3 and 16 in the sarcomatoid component

Acquired cystic disease (ACD)‐associated renal cell carcinoma (RCC) has recently been established. Herein we report the sixth case of ACD‐associated RCC with a sarcomatoid change. The patient was a 77‐year‐old man who regularly underwent hemodialysis for 14 years due to chronic renal failure resulting from IgA nephropathy. On computed tomography, a large right RCC was observed with contrast enhancement in the arterial phase. A nodular protrusion into the perirenal fat was detected. Right nephrectomy was performed under laparoscopy. Surgically resected specimens revealed a tan‐to‐yellow tumor (95 × 75 × 55 mm) with a whitish nodule (20 × 15 × 15 mm) invading into the perirenal fat. Histopathologically, the large carcinoma component of the tumor displayed a cribriform or microcystic growth pattern with deposition of oxalate crystals. The whitish nodule corresponded to the sarcomatoid component, and the spindled and pleomorphic tumor cells showed diffuse positivity of p53 on immunohistochemistry. Fluorescence in situ hybridization revealed trisomy of chromosomes 3 and 16 in the carcinoma component, as was expected from the literature. In addition, increased polysomy of these chromosomes was also observed in the sarcomatoid component. This finding may be related to the development of the sarcomatoid component along with the TP53 mutation.