川辺 則彦

The natural history of intracholecystic papillary neoplasm (ICPN), especially the speed of growth from small benign to a carcinomatous lesion, is quite unrevealed. Here, we report an extremely rare case of ICPN, in which the papillary lesion was observed transforming from small and benign to malignant using abdominal ultrasound (AUS) over 2 years during routine health checks. A 44-year-old man underwent a routine health check-up. The initial AUS showed a small sessile polyp in the gallbladder, which enlarged slightly at the next AUS, a year later. In the third year, the polypoid lesion enlarged markedly, with a maximum diameter of 10 × 9 × 7 mm. Therefore, a laparoscopic cholecystectomy was performed. Microscopically, the 10 mm tumor had intracytoplasmic mucus, and a clear cytoplasm compatible with gastric-type features. Immunohistochemical analysis showed positive staining of atypical cells for MUC6 and PAS. These findings led to the diagnosis of ICPN with high-grade intraepithelial neoplasia of the gastric type. In conclusion, sessile polyps with rapid growth might be a crucial finding in the early stage of ICPN.

BACKGROUND: The association between pancreatic fistula (PF) after pancreaticoduodenectomy (PD) and preoperative exocrine function is yet to be elucidated. This study aimed to evaluate the association between the preoperative results of the 13C-trioctanoin breath test and the occurrence of PF, showing the clinical relevance of the breath test in predicting PF. METHOD: A total of 80 patients who underwent 13C-trioctanoin breath tests prior to PD from 2006 to 2018 were included in this study. Univariate and multivariate analyses were conducted to reveal the preoperative predictors of PF, showing the association between 13C-trioctanoin absorption and PF incidence. RESULTS: Among 80 patients (age, 68.0 ± 11.9 years, 46 males and 34 females; 30 pancreatic ductal adenocarcinoma [PDAC]/50 non-PDAC patients), the incidence of PF was 12.5% (10/80). Logistic regression analysis results revealed that the frequency of PF increased significantly as the 13C-trioctanoin breath test value (Aa% dose/h) increased (odd's ratio: 1.082, 95% confidence interval: 1.007-1.162, p = 0.032). Moreover, the optimal cutoff value of the preoperative fat absorption level to predict PF was 38.0 (sensitivity, 90%; specificity, 74%; area under the curve, 0.78; p = 0.005). Indeed, the incidence of PF was extremely higher in patients whose breath test value was greater than 38.0 (33%, 9/27) compared with that in patients with values less than 38.0 (1.8%, 1/53). CONCLUSIONS: Favorable preoperative fat absorption evaluated using the 13C-trioctanoin breath test is a feasible and objective predictor of PF after PD.

The two patterns of pathogenesis for pancreatic colloid carcinoma are reported; (1) progression from ordinary ductal adenocarcinoma, a subtype of invasive pancreatic ductal carcinoma, and (2) progression from papillary adenocarcinoma derived from intraductal papillary mucinous neoplasm (IPMN) or mucinous cystic neoplasm (MCN). Whether these two conditions are the same disease remains controversial. Case Report 1. An 81-year-old woman was evaluated for an increased carbohydrate antigen 19-9 (CA19-9) value (130 U/mL) detected at 4-year follow-up after distal pancreatectomy for IPMN. Based on the image findings, a local recurrence of IPMN was diagnosed, and the patient underwent a remnant total pancreatectomy. Histopathologic findings showed marked mucus production from the tumor, also noteworthy because mucous nodule formation occurs in more than 80% of tumor. Fibrosis around the mucous cavity was noted, and a low papillary lesion was found in part of the cyst wall, which was contiguous to a flat, basal area; its nucleus was enlarged and heterogeneous in size, which is considered to be a component of intraductal papillary mucinous (IPMC). Therefore, the patient was diagnosed with pancreatic colloid carcinoma derived from IPMN. Case report 2 a 71-year-old man was evaluated for jaundice. Based on the image findings, a diagnosis of pancreatic head cancer was made, and a substomach preserving pancreaticoduodenectomy was performed. Histologically, marked mucus production and floating cuboidal masses of atypical cells without mucinous nodules were seen. Mucinous nodule formation is observed in more than 80% of tumor, but there was no IPMN component, which led to the diagnosis of pancreatic colloid carcinoma. In conclusion, there might be two types of colloid carcinoma of the pancreas, and further study is needed to determine whether these diseases are truly the same or not.

BACKGROUND: Performing major hepatectomy for patients with marginal hepatic function is challenging. In some cases, the procedure is contraindicated owing to the threat of postoperative liver failure. In this case report, we present the first case of marginal liver function (indocyanine green clearance retention rate at 15 min [ICGR15]: 28%) successfully treated with right hepatectomy, resulting in total caudate lobe preservation. CASE PRESENTATION: A 71-year-old man was diagnosed with sigmoid colon cancer with three liver metastases (S5, S7, and S8). All of metastatic lesions shrunk after chemotherapy, but his ICGR15 and indocyanine green clearance rate (ICGK) were 21% and 0.12, respectively. Moreover, the remnant liver volume was only 39%. Therefore, portal venous embolism (PVE) of the right portal vein was suggested. Portography showed divergence of the considerably preserved right caudate lobe branch (PV1R) from the root of the right portal vein. The liver function was reevaluated 18 days after PVE was suggested. During this time, the ICGR15 (21-28%) and ICGK rate (0.12-0.10) deteriorated. The right caudate lobe was significantly enlarged; thus, a total caudate lobe-preserving hepatectomy (TCPRx) was performed. Patients eligible for TCPRx included those with (1) hepatocellular carcinoma or metastatic liver cancer, (2) no tumor in the caudate lobe, (3) marginal liver function (ICG Krem greater than 0.05 if TCPRx was adapted; otherwise, less than 0.05) and Child-Pugh classification category A, and (4) preserved PV1R and right caudate bile duct branch. The procedure was performed through (A) precise estimation of the remnant liver volume preoperatively, (B) repeated intraoperative cholangiography to confirm the biliary branch of the right caudate lobe (B1R) conservation, and (C) stapler division of posterior and anterior Glisson's pedicles laterally to avoid injuries to the PV1R and B1R. CONCLUSIONS: Right hepatectomy with total caudate lobe preservation, following PVE, was a safe and viable surgical technique for patients with marginal liver function.