Masahiro Nakahara

Frequent alterations in the Wnt signaling pathway in colorectal cancer with microsatellite instability

It is generally accepted that both dysfunction of the Wnt signaling pathway, including mutations in the adenomatous polyposis coli (APC) and β‐catenin genes, and genetic instability play important roles in colorectal carcinogenesis. However, alteration of the components in the Wnt signaling pathway in colorectal cancer (CRC) with microsatellite instability (MSI) has not been elucidated. In order to assess the status of the Wnt signaling components in CRC with MSI, mutational analyses of the β‐catenin, APC, Axin 1, and T cell factor 4 (TCF4) genes were performed. Three of 33 samples had mutations in exon 3 of the β‐catenin gene and two in the APC gene. Eight mutations in seven samples were detected by single‐strand conformation polymorphism and subsequent direct sequence analysis of the entire coding region of the Axin 1 gene. Furthermore, TCF4, which is one of the transcriptional factors in the Wnt signaling pathway and has a mononucleotide repeat sequence (a nine‐ adenine repeat, (A)9) in its C‐terminal region, was mutated in 13 of the 33 samples. Thus, alteration in the Wnt signaling pathway is frequently observed in CRC with MSI, including hereditary nonpolyposis colorectal cancer, as well as in familial adenomatous polyposis and sporadic CRC without MSI.

HEPATOBLASTOMA IN AN ADULT ASSOCIATED WITH C-MET PROTO-ONCOGENE IMBALANCE

A rare case of hepatoblastoma in a 61‐year‐old Japanese housewife is described. This liver tumor mainly consisted of two tissue components: embryonal hepatocytes and primitive mesenchymal tissue. Fetal hepatocytes with alpha‐fetoprotein production, gland formation, cartilage and osteoid were also found in a small portion. Molecular analysis by slot blot method revealed increased copy numbers of c‐met and K‐sam proto‐oncogenes and cyclin D1 genes. These findings suggest that alterations of these oncogenes might play a role in the development of adult hepatoblastoma.

Complete spontaneous necrosis of hepatocellular carcinoma confirmed on resection: A case report

Highlights • Spontaneous necrosis of hepatocellular carcinoma without any pretreatment or angiography is extremely rare.• Spontaneous necrosis of HCC was highly suspected given the history of alcoholic hepatitis, based on the elevation of AFP and the CT findings.• The mechanisms of spontaneous regression are still unclear.• Recurrence after regression or viable malignant cells in resected specimen are reported.• The ideal management strategy for this disease is surgical intervention if the liver function is acceptable.

Inflammatory fibroid polyp of the ileum with the appearance of a borrmann type II lesion, caused by colostomy irrigation: Report of a case

Inflammatory fibroid polyps (IFPs) are rarely found in the gastrointestinal tract. The majority of IFPs are sessile-pedunculated or pedunculated polypoid lesions, whereas a polyp presenting like a Borrmann type II lesion is extremely unusual. This report describes the case of a 74-year-old man with a history of intussusception, in whom a preoperative diagnosis of a cecal tumor of the ileocecal valve was made. A laparotomy subsequently revealed a lesion similar to a Borrmann type II tumor located 15 cm above the ileocecal valve, but not at the valve. The lesion was diagnosed as an IFP which had been caused by repeated colostomy irrigation. The aim of the present report is to draw attention to this entity, which should be included in the differential diagnosis of intussusception and small bowel obstruction.

Methotrexate-associated primary hepatic malignant lymphoma following hepatectomy: A case report

Highlights • Primary hepatic lymphoma is difficult to diagnose preoperatively.• MTX use encouraged MTX-related ML.• In MTX-related MLs, withdrawing MTX had a therapeutic effect.

Adrenal failure due to bilateral adrenal metastasis of rectal cancer: A case report

Highlights • Bilateral adrenal metastases can be lead to adrenal insufficiency.• A rapid ACTH test is useful to diagnose adrenal insufficiency.• Adrenal crisis may be fatal if not promptly recognized and treated.

Characteristics of the portal vein thrombosis recurrence pattern without liver parenchymal invasion from colorectal cancer: a case report

BackgroundPortal vein tumor thrombosis from colorectal cancer is rare, and this recurrence pattern was mainly reported in patients with renal cell carcinoma and hepatocellular carcinoma. Furthermore, the recurrence pattern of portal vein tumor thrombosis without liver parenchymal invasion from colorectal carcinoma has not been previously reported. Herein, we present a patient with progressive portal vein tumor thrombosis without liver parenchymal invasion following curative resection.Case presentationA 61-year-old man with a chief complaint of constipation with abdominal pain associated with rectal carcinoma was admitted to our hospital. Computed tomography (CT) showed that the rectosigmoid colon wall was thickened, regional lymph nodes were swollen, and the light space-occupying lesion (SOL) was detected at segment 8 (S8). Neoadjuvant chemotherapy was performed, which was followed by laparoscopic anterior resection. The final diagnosis was stage IIIb (SS, N2, M0). After operation, systemic adjuvant chemotherapy was introduced. At first, tumor marker levels were within the normal range and there were no accumulations on positron emission tomography (PET). Tumor marker levels were elevated, and contrast-enhanced CT demonstrated that the portal vein SOL slowly extended from S8 to S5. Additionally, PET showed that the standardized uptake value was abnormally high at 5.8. Based on the diagnosis of portal vein tumor thrombosis, right hepatectomy was performed. On pathological analysis, tumor thrombosis was associated with rectal carcinoma, and there was no invasion toward the liver parenchyma. Additionally, the surgical cut end was tumor free. Six months after the hepatectomy, the paraaortic lymph nodes showed swelling. The patient is currently undergoing systemic chemotherapy.ConclusionAggressive surgical resection should be considered in cases of portal vein tumor thrombosis. A good long-term prognosis could be obtained by a combination of curative resection and systemic chemotherapy.

Palliative surgery for advanced gastric cancer: Partial gastrectomy using the inverted laparoscopic and endoscopic cooperative surgery method

Highlights • We performed partial gastrectomy with LECS as palliative treatment.• It was an invasive gastric cancer, but the patient had many comorbidities.• LECS was successfully used as minimally invasive palliative treatment.

Impact of comorbidities on the postoperative outcomes of acute cholecystitis following early cholecystectomy

PurposesThe purpose of this study was to evaluate the influence of comorbidities on the surgical outcomes of early cholecystectomy for acute cholecystitis.MethodsData were retrospectively collected for patients with acute cholecystitis who underwent early cholecystectomy. Patients were separated into three groups based on the cholecystitis severity grade, and the surgical outcomes of early cholecystectomy were analyzed. Patients with mild and moderate cholecystitis were subdivided into a comorbidity group (n = 10) and a non-comorbidity group (n = 83).ResultsThere were 57 (55.3%) patients with mild cholecystitis, 36 (35.0%) with moderate cholecystitis, and 10 (9.7%) with severe cholecystitis. The surgical outcomes were significantly worse for patients with severe cholecystitis than for patients with mild or moderate cholecystitis. There were no postoperative deaths after cholecystectomy. There were no significant differences in the complication rate (P = 0.629), conversion rate (P = 0.114), or intraoperative blood loss (P = 0.147) between the comorbidity and non-comorbidity groups.ConclusionOur findings suggest that early cholecystectomy can be performed safely for patients with mild and moderate cholecystitis even if comorbidities are present. Early cholecystectomy may be an alternative treatment strategy for patients with severe cholecystitis who are candidates for anesthesia and surgery.

Mixed adenoneuroendocrine carcinoma derived from the cystic duct: A case report

Highlights • We report here an extremely rare case of mixed adenoneuroendocrine carcinomas (MANECs) derived from cystic duct. Histologically, the tumor had components of both well-differentiated tubular adenocarcinoma and neuroendocrine carcinoma with massive venous invasion.• R0 resection was established, but the risk of recurrence in liver was estimated to be significantly high, due to the detected venous invasion of the neuroendocrine carcinoma in the resection margin of the hepatic duct. Eight months after surgery, multiple liver metastases were discovered, and treatment with adjuvant chemotherapy was initiated.• Though standards of diagnosis and treatment for MANECs of the bile duct have not been established, multidisciplinary therapy is necessary to improve outcomes.