Leucine-rich repeat-containing G protein-coupled receptor 5 expression in lymph node metastases of colorectal cancer: Clinicopathological insights and prognostic implications.

Leucine-rich repeat-containing G protein-coupled receptor 5 (LGR5), a significant cancer stem cell marker in colorectal cancer (CRC), lacks lymph node (LN) expression studies. In this study, we identified LGR5 expression by RNAscope, a highly sensitive RNA in situ method, and analyzed its association with clinicopathological characteristics. Tissue microarrays were generated from primary tumors (PTs) and LN metastases in paraffin-embedded blocks of 38 CRC surgical resection materials. LGR5 expression by RNAscope was evaluated by dividing the expression levels into negative and positive expression. In all but two cases of LN metastasis, LGR5-positive dots were detected in tumor cells, and there was a wide range of LGR5-positive cells. More LGR5-positive dots were identified in the gland-forming region. Twenty-three cases were classified into a high LGR5-expression group, and 15 cases were classified into a low LGR5-expression group. In the high LGR5-expression group, the histological grade was lower than in the low LGR5-expression group (p = 0.0159), while necrosis was significantly more prevalent (p = 0.0326), and the tumor, node, metastasis stage was significantly lower (p = 0.0302). There was no association between LGR5 expression levels in LN metastases and LGR5 expression levels in PT tissue. LGR5 expression in LN metastases may influence prognosis. Further analysis may lead to new therapeutic strategies.

Mucosal damage in pancreaticobiliary maljunction is stronger in the gallbladder than in the bile duct.

BACKGROUND: The frequency of gallbladder carcinoma is high in pancreaticobiliary maljunction (PBM), and the mechanism of carcinogenesis is not well understood. METHODS: The expression of γH2AX, the most sensitive marker for detecting DNA damage, was analyzed using immunohistochemistry in patients with PBM, in which the gallbladder and bile duct were simultaneously resected. Gallbladder and bile ducts were evaluated in non-neoplastic regions in 13 cases of PBM without cancer in the gallbladder and bile ducts. RESULTS: The median frequencies of γH2AX expression in the bile duct and gallbladder within the same case were 5.9% (range 1.7-12.05%) and 9.9% (range 2.8-25%), respectively, and were significantly higher in the gallbladder mucosa (P < 0.0004). γH2AX expression strongly correlated in the bile duct and gallbladder (r = 0.9436, P < 0.0001). PBM caused marked mucosal damage to the gallbladder. CONCLUSIONS: Mucosal damage may be involved in carcinogenesis, which may be useful for predicting malignant transformation.

Pyogenic liver abscess associated with Klebsiella oxytoca: Mimicking invasive liver abscess syndrome.

A pyogenic liver abscess (PLA) is a space-occupying lesion in the liver that is associated with significant morbidity and mortality. We herein present the case of a Japanese 76-year-old man who visited our hospital with fever and back pain lasting 3 weeks after endoscopic treatment for common bile duct stones. He was accompanied by poorly controlled diabetes mellitus (DM) with an HbA1c of 9.7 %. Laboratory tests disclosed elevated C-reactive protein level (22.1 mg/dL) and white cell count (11,910/µL). Abdominal computed tomography (CT) revealed hypodense lesions in the right liver lobe, with abdominal ultrasonography showing an echogenicity-mixed hypoechoic lesion. Percutaneous needle aspiration of a liver lesion was performed under suspicion of a PLA. Subsequent enhanced CT and magnetic resonance imaging confirmed the hepatic lesions in the right lobe as well as a septic pulmonary embolism, right hepatic vein thrombosis, spondylodiscitis, and a retroperitoneal abscess. Gram staining of the abscess drainage revealed gram-negative bacteria. The above findings indicated invasive liver abscess syndrome (ILAS) caused by Klebsiella pneumoniae. However, further examination of blood, urine, and abscess drainage cultures revealed positivity for Klebsiella oxytoca. This case illustrates that K. oxytoca may cause ILAS-like symptoms. Screening for systemic metastatic infection should be considered in patients with PLA due to K. oxytoca in whom therapeutic intervention has been delayed, especially in patients with poorly controlled DM.

ARL4C is associated with epithelial-to-mesenchymal transition in colorectal cancer.

BACKGROUND: ADP-ribosylation factor-like protein 4 C (ARL4C) is a member of the ARF small GTP-binding protein subfamily. The ARL4C gene is highly expressed in colorectal cancer (CRC). ARL4C protein promotes cell motility, invasion, and proliferation. METHODS: We investigated the characteristics of ARL4C by comparing its expression at the invasion front and relationships with clinicopathological data using RNAscope, a highly sensitive RNA in situ method. RESULTS: In all cases, ARL4C expression was observed in cancer stromal cells and cancer cells. ARL4C expression in cancer cells was localized at the invasion front. In cancer stromal cells, ARL4C expression was significantly stronger in cases with high-grade tumor budding than in cases with low-grade tumor budding (P = 0.0002). Additionally, ARL4C expression was significantly increased in patients with high histological grade compared with those with low histological grade (P = 0.0227). Furthermore, ARL4C expression was significantly stronger in lesions with the epithelial-to-mesenchymal transition (EMT) phenotype compared with the non-EMT phenotype (P = 0.0289). In CRC cells, ARL4C expression was significantly stronger in cells that had the EMT phenotype compared with those with a non-EMT phenotype (P = 0.0366). ARL4C expression was significantly higher in cancer stromal cells than in CRC cells (P < 0.0001). CONCLUSION: Our analysis reinforces the possibility that ARL4C expression worsens the prognosis of patients with CRC. Further elucidation of the function of ARL4C is desired.

[A case of "colitis-like intestinal Behçet's disease" accompanied by ulcerative colitis after the development of myelodysplastic syndrome].

A 71-year-old man developed ulcerative colitis (UC) at 48 years of age. As a steroid-dependent case with poor UC control, the patient was treated with azathioprine, which resulted in clinical remission. However, a blood test revealed pancytopenia. Bone marrow examination confirmed the diagnosis of myelodysplastic syndrome (MDS). During the patient's clinical course, multiple round ulcers appeared in the terminal ileum. We suspected concomitant "colitis-like intestinal Behçet's disease" (BD). Treatment with adalimumab resolved the ulcers. To the best of our knowledge, this is a rare case of intestinal BD accompanying UC after MDS.

Correlation of LGR5 expression and clinicopathological features in intrahepatic cholangiocarcinoma.

Leucine-rich repeat-containing G-protein-coupled receptor 5 (LGR5) is a known cancer stem cell marker. However, there are no reported analyses of LGR5 mRNA expression in normal liver and liver cancer tissues. Here, we evaluated LGR5 expression by RNAscope, a newly developed RNA in situ hybridization technique, using a tissue microarray consisting of 25 samples of intrahepatic cholangiocarcinoma (ICC) selected from the medical archives at our hospital. LGR5 expression levels were divided into high and low expression groups by the five-grade scoring system, and clinicopathological features were analyzed. Low LGR5 expression was identified in some normal hepatocytes and bile duct cells. In addition, LGR5 expression was identified in all bile duct cancer samples except one case. Well-differentiated to moderately-differentiated adenocarcinoma tended to show higher LGR5 expression than poorly-differentiated adenocarcinoma (P = 0.0561), and the large duct type showed significantly higher LGR5 expression levels than the small duct type (P = 0.0225). Patients in the high LGR5 expression group tended to have good overall survival (OS) (P = 0.0623). The Cox proportional hazard regression model revealed that the high LGR5 expression group showed independently better OS for ICC (P = 0.0285). High LGR5 expression is possibly a good prognosis factor in ICC. However, the detailed mechanism of LGR5 in this disease remains unclear, and further analysis is warranted.

[An autopsy case of nasal-type primary gastric extranodal NK/T-cell lymphoma with early liver failure].

An 82-year-old woman was admitted to the hospital because of tiredness and fever. She was diagnosed with acute hepatitis. Although the cause of acute hepatitis was undetermined, her health condition and liver function improved, and she was discharged. Four weeks later, she was hospitalized again because of anorexia. Laboratory data revealed worsened anemia. Endoscopy results revealed a huge ulcerative lesion in the lesser curvature of the stomach. After 4 days, she vomited blood and died of hemorrhagic shock. The autopsy revealed a nasal-type primary gastric extranodal NK/T-cell lymphoma (ENKTL). Although no lymphoma cells were found in the liver biopsy collected during the first hospitalization, lymphoma cells and lymphocytes in the liver tissue were identified during autopsy because the lymphoma had infiltrated the liver. Primary gastric ENKTL is extremely rare and poorly understood. However, the general prognosis of progressive ENKTL is poor. Early diagnosis of liver metastasis of lymphoma cells is difficult;thus, in some cases, lymphoma metastases to the liver are diagnosed during autopsy. Although further experiments are required, we report a rare case of primary gastric ENKTL.

LGR5 expression and clinicopathological features of the invasive front in the fat infiltration area of pancreatic cancer.

BACKGROUND: Leucine-rich repeat-containing G-protein-coupled receptor 5 (LGR5) is a strong cancer stem cell marker in colorectal cancer; however, there are many unclear aspects of LGR5 expression in pancreatic cancer. It has been reported that the interaction between tumor cells and stroma at the fat infiltration site has a significant effect on pancreatic cancer prognosis. Therefore, we report a clinicopathological study of LGR5 expression at the fat invasion front in pancreatic cancer. METHODS: LGR5 expression was analyzed in 40 pancreatic ductal adenocarcinoma cases with RNAscope, which is a newly developed high-sensitivity in situ hybridization method. Epithelial-mesenchymal transition (EMT) was analyzed by the expression of E-cadherin and vimentin via immunohistochemistry. RESULTS: LGR5-positive dots were identified in all cases, especially with glandular formation. In the fat invasion front, a high histological grade showed significantly reduced LGR5 expression compared with a low histological grade (p=0.0126). LGR5 expression was significantly higher in the non-EMT phenotype group than in EMT phenotype group (p=0.0003). Additionally, LGR5 expression was significantly lower in cases with high vascular invasion than in those with low vascular invasion (p=0.0244). CONCLUSIONS: These findings suggest that decreased LGR5 expression in the fat invasion front is associated with more aggressive biological behavior in pancreatic ductal adenocarcinoma, with higher tumor grade, EMT phenotype, and higher vascular invasion.