Multicenter analysis of the efficacy of early cholecystectomy and preoperative cholecystostomy for severe acute cholecystitis: a retrospective study of data from the multi-institutional database of the Hiroshima Surgical Study Group of Clinical Oncology.

BACKGROUND: Severe acute cholecystitis (AC) is a challenging disease because it comprises coexisting systemic infections that lead to vital organ dysfunction. This study evaluated the optimal surgical timing and efficacy of preoperative percutaneous cholecystostomy (PC) for patients with severe AC. METHODS: Data of 142 patients who underwent cholecystectomy for severe AC between 2011 and 2021 were retrospectively collected from the multi-institutional database of the Hiroshima Surgical Study Group of Clinical Oncology. Patients were divided into the early cholecystectomy (EC) group (within 72 h of symptom onset) and delayed cholecystectomy (DC) group. They were also subdivided into the upfront cholecystectomy group and preoperative PC before cholecystectomy group. The diagnosis and severity of AC were graded according to the Tokyo Guidelines 2018. Clinicopathological variables and outcomes were compared. RESULTS: No significant differences in age, body mass index, American Society of Anesthesiologists (ASA) classification, and Charlson comorbidity index between the EC and DC groups were observed. Preoperative drainage was more commonly performed for the DC group than for the EC group. Local severe AC features were more commonly detected in the DC group than in the EC group. The postoperative outcomes of the EC and DC groups were comparable. Compared to the PC before cholecystectomy group, the upfront cholecystectomy group included more patients with ASA physical status ≥ 3 and more patients who used oral warfarin. Warfarin usage and cardiovascular dysfunction rates of the PC after cholecystectomy group were higher than those of the upfront cholecystectomy group. PC was associated with significantly less intraoperative bleeding and shorter hospital stays. CONCLUSIONS: Patients who can tolerate general anesthesia are good candidates for EC. Patients who use warfarin and those with cardiovascular dysfunction are considered to be at high risk for postoperative complications; therefore, to prevent AC recurrence during the waiting period, PC before cholecystectomy during the same admission is more appropriate than upfront cholecystectomy for these patients.

Effect of body fat mass loss on prognosis of radical resection for pancreatic ductal adenocarcinoma based on bioelectrical impedance analysis.

BACKGROUND: Few reports have performed a prognostic analysis based on bioelectrical impedance analysis in patients with radical resection of pancreatic ductal adenocarcinoma (PDAC), and its usefulness in prognostic analysis remains unclear. This study aimed to evaluate body composition changes in patients undergoing radical resection for PDAC and analyze its impact on prognosis. METHODS: The medical records of radical resection for patients with PDAC were retrospectively reviewed, and the parameters of body composition, including body weight, skeletal muscle mass, body fat mass (BFM), and extracellular water-total body water ratio, from preoperatively to 12 months postoperatively, for each surgical procedure were measured based on direct segmental multifrequency bioelectrical impedance analysis with an InBody 770 (InBody Inc., Tokyo, Japan) device. The clinicopathological and prognostic factors were analyzed. RESULTS: Among 79 patients who underwent radical resection for PDAC, 36 (46%), 7 (8%), and 36 (46%) underwent pancreatoduodenectomy, total pancreatectomy, and distal pancreatectomy, respectively. The multivariate overall survival analysis demonstrated that BFM loss percentage at 1 month postoperatively ≧14% (p = 0.021), lymph node metastasis (p = 0.014), and non-adjuvant chemotherapy (p <  0.001) were independent poor prognostic factors. Multivariate analysis revealed that preoperative BFM < 12 kg and preoperative albumin < 3.5 g/dL were independently associated with BFM loss percentage at 1 month postoperatively ≧14% (p = 0.021 and p = 0.047, respectively). CONCLUSIONS: Loss of BFM in the early postoperative period may have a poor prognosis in radical resection of PDAC.

Prognosis of repeat hepatectomy for liver transplantable hepatocellular carcinoma recurrence after hepatectomy: a Retrospective Cohort Study with the Hiroshima Surgical Study Group of Clinical Oncology (HiSCO).

PURPOSE: Factors affecting the prognosis of repeat hepatectomy for transplantable hepatocellular carcinoma (HCC) recurrence after hepatectomy remain unclear. We aimed to clarify the prognostic factors for transplantable hepatocellular carcinoma recurrence after hepatectomy. METHODS: We included 1758 primary and 486 repeat hepatectomies out of 2244 for HCC performed between 2006 and 2017 using the Hiroshima Study Group for Clinical Oncology and Surgery database. We first compared survival rates of primary and repeat hepatectomy patients. Subsequently, prognostic factors were analyzed in patients who underwent a repeat hepatectomy for transplantable hepatocellular carcinoma recurrence after hepatectomy (defined as age < 70 years at the time of recurrence and recurrent tumor morphology that meets the Milan criteria). RESULTS: The 5-year overall survival rate (OS) after repeat hepatectomy was 63.2%, while the 5-year recurrence-free survival rate (RFS) was 23.7%. RFS demonstrated significant inferiority in the repeat hepatectomy group than in the primary hepatectomy group; however, OS did not present a notable difference between the two cohorts. In the transplantable recurrence group, mALBI grade 2b, max tumor size > 20 mm, and multiple tumors were independent prognostic risk factors for overall survival. Patients with two or more risk factors had a significantly lower survival rate (only 30.6% at 5 years) compared to those with one or fewer risk factors (81.8% at 5 years). CONCLUSIONS: We identified the risk factors involved in post-hepatectomy survival for patients with transplantable recurrence after hepatectomy. The results are a potential indicator of whether salvage liver transplantation should be considered during repeat hepatectomy.

[Surgical Resection and Adjuvant Chemotherapy for Early Multiple Peritoneal Recurrence after Rejection of Hepatocellular Carcinoma-A Case Report].

Thus far, no consensus has been reached regarding the treatment of peritoneal dissemination of hepatocellular carcinoma (HCC). Here, we report a case of surgical resection and postoperative adjuvant chemotherapy for early multiple peritoneal recurrences of HCC. A 74-year-old man was found to have hepatic mass of 80 mm in size in S7 and 57 mm in S8, and was diagnosed with HCC. The patient underwent an open anterior segmentectomy and S7 subsegmentectomy of the liver. Peritoneal washing cytology revealed the presence of malignant cells. The tumor strongly adhered to the diaphragm, necessitating partial resection of the diaphragm. Six months after surgery, multiple disseminated recurrences were found on the CT scan. Atezolizumab plus bevacizumab combination therapy was initiated, but tumor size enlargement and elevation of tumor markers were observed after 3 courses. Resection of the dissemination(2 on the surface of the lung right lower lobe, 1 on the right renal superior retroperitoneum, 1 on the omentum, and 1 invading the jejunum)was performed. Considering the high risk of recurrence, postoperative adjuvant chemotherapy with lenvatinib was administered for 1 year. No recurrence has been found for 16 months after the resection. Although more cases are needed to conclude, this case report suggests that surgical resection and postoperative administration of lenvatinib may be effective in the treatment of disseminated HCC lesions at a high risk of recurrence.

[Unresectable Esophageal Cancer on the Elderly Woman Which Was Treated Effectively with Ipilimumab plus Nivolumab-A Case Report].

Until now, the standard treatment regimen was cisplatin plus 5-FU as the chemotherapy for unresectable advanced esophageal cancer. Immune checkpoint inhibitors have brought about changes to the cancer treatment. Ipilimumab plus nivolumab was approved in June 2022 for unresectable advanced esophageal cancer. An 86-year-old woman who was normal ADL and cognitive function was diagnosed with unresectable esophageal cancer with multiple lymph node metastasis. We thought surgery or chemotherapy is impossible because of her age and health status, so we treated with ipilimumab plus nivolumab. After 2 cycles, tumor became reduced in size on endoscopic examination and accumulation in primary lesion and lymph node metastases was decreased considerably on positron emission tomography/computed tomography(PET-CT). Though the cycle after initiation of chemotherapy was uneventful, tumor regrowth on the examinations at 5 months. The patient's condition of the disease was improved temporarily after change chemotherapy to paclitaxel as the second-line therapy, but she died due to disease progression at 11.4 months from initiation of treatment. Ipilimumab plus nivolumab can become one of the effective treatments for patients who are impossible to treat with conventional chemotherapy.

[A Case of Pancreatoduodenectomy for Multiple Nonfunctioning Neuroendocrine Tumors of the Duodenum].

A 42-year-old woman was referred to our hospital because of incidentally discovered multiple neoplastic lesions of the duodenum. Upper gastrointestinal endoscopy showed there were more than 10 submucosal tumors and less than 10 mm in diameter. Histological examination of the biopsy specimen revealed nonfunctioning neuroendocrine tumor(NET). Enhanced computed tomography(CT)showed neither regional lymph node nor distant metastasis, so we performed pancreatoduodenectomy with regional lymph node dissection. Pathological examination showed multiple NET G2 less than 5 mm in size with invasion to muscularis propria and 3 lymph node metastases, so diagnosed as pT2(m)N1M0, Stage Ⅲ. She is alive without tumor recurrence for 14 months after surgery. In general, sporadic nonfunctioning NET of the duodenum less than 10 mm in diameter has low possibility of lymph node metastasis. However, our case suggested the possibility of lymph node metastasis in patients with multiple NETs of the duodenum, in spite of small size. Therefore, pancreatoduodenectomy with regional lymph node dissection should be considered for multiple nonfunctioning NETs of the duodenum.

[A Case of Anal Canal Cancer with Pagetoid Spread and a Significant Response to Preoperative Chemoradiotherapy].

Perianal Pagetoid spread is a rare condition for which there is no proven therapy. We experienced a case of anal canal cancer with Pagetoid spread which exhibited a significant response to preoperative chemoradiotherapy(CRT). A 76-year-old man with anal stenosis was referred to our hospital. He was diagnosed with anal canal cancer with Pagetoid spread. No infiltration into the surrounding tissue was observed, but metastasis to the left inguinal lymph node was noted. The patient received preoperative CRT(oral S-1, 1.8 Gy×25 Fr, a total dose of 45 Gy)including the bilateral inguinal region. After CRT, the main tumor size was reduced and PET-CT showed disappearance of the abnormal accumulation in the left inguinal lymph nodes. Laparoscopic abdominoperineal resection and left inguinal trans lymphadenectomy were performed. The macroscopic findings of the surgical specimen confirmed no residual carcinoma or lymph node metastasis. Although more proof is needed, this case suggested that CRT may be effective for anal canal cancer with pagetoid spread.

[A Case of Laparoscopic Surgery for Colon Metastasis of Renal Cancer].

A 67-year-old man underwent laparoscopic partial left nephrectomy for renal cell carcinoma 2.5 years ago. CT showed a well-defined 3 cm mass with contrast effect bordering on the descending colon, and PET-CT showed an accumulation of SUVmax 6.01 in the same area. Colonoscopy revealed a submucosal tumor-like mass in the descending colon. The patient was diagnosed with a local recurrence of renal cell carcinoma and invasion of the descending colon, and laparoscopic colectomy was performed. The excised specimen was a pale yellowish submucosal tumor measuring 4.5×3.8 cm, which was histologically diagnosed as metastasis of clear cell renal cell carcinoma. Surgical resections for metastases of renal carcinoma have been reported and expected prolong survival. We report a case of laparoscopic colon resection for recurrence of descending colon metastasis of renal cell carcinoma.

[A Case of Sclerosing Angiomatoid Nodular Transformation Resected for Suspected Relapse of Diffuse Large B-cell Lymphoma].

We report a case of sclerosing angiomatoid nodular transformation(SANT)5 years after remission of diffuse large B-cell lymphoma(DLBCL). A 64-year-old woman was diagnosed a nodular mass at the spleen by a contrast-enhanced CT scan 5 years after the relief for DLBCL. The mass showed accumulation of FDG. Because the possibility of the recurrence of malignant lymphoma could not be ruled out, laparoscopic splenectomy was performed for diagnosis and treatment. Immunohistologically, the resected mass revealed 3 different vascular components pattern(CD31, CD34 and CD8), so we diagnosed SANT. It is difficult to distinguish from malignant lymphoma or cancer even with various examination, so laparoscopic splenectomy is useful for diagnosis and treatment.

[A Case of Lynch Syndrome with Repeated Asynchronous Colorectal Cancer in a Short Period].

This case was a 73-year-old woman who previously underwent a partial colectomy for ascending colon cancer at the age of 70. She had a history of cancer of the uterus, descending colon, bladder, and left ureter. She had a family history of colorectal cancer and met the Amsterdam Ⅱ criteria for Lynch syndrome. She was diagnosed as Lynch syndrome with a MSH2 germline mutation by genetic analysis. One year later, a partial colectomy was performed for sigmoid colon cancer. Six months later, colonofiberscopy revealed early-stage cancer in the rectum, and EMR was performed. Despite adequate surveillance, she had frequent recurrences of advanced colorectal cancer within a short period of time. We report here risk factors of colorectal cancer in Lynch syndrome and indications for prophylactic total colectomy.

Postoperative Portal Hypertension Enhances Alloimmune Responses after Living-Donor Liver Transplantation in Patients and in a Mouse Model.

Controlling portal vein pressure in living-donor liver transplantation has received increased attention owing to its potential importance for graft survival. Portal hypertension may lead to the activation of liver-resident APCs, including liver sinusoidal endothelial cells (LSECs), which have immunological tolerogenic capacity. We investigated the effects of portal hypertension on graft survival and the antidonor immune response using clinical data and a mouse model. We categorized patients (n = 136) according to their portal vein pressure values at the end of surgery. Using propensity score-matching analyses, we found that portal hypertension was significantly associated with a higher antidonor immune response and incidence of acute rejection. To investigate the mechanism, we performed an allogeneic coculture assay using a 70% hepatectomized (HTx) mouse model with or without a portosystemic shunt. Liver cells from HTx mice without a shunt exhibited a significantly greater anti-BALB/c B6 T cell response than those from sham-operated mice or HTx mice with a shunt. LSECs from sham-operated mice, but not from HTx mice, suppressed the B6 T cell alloresponse in a dose-dependent manner. Furthermore, LSECs from HTx mice without a shunt showed significantly downregulated MHC class I/II and programmed death-ligand 1 expression, and those from mice with a shunt showed recovered expression of these molecules. Postoperative portal hypertension enhances alloimmune responses in recipients after living-donor liver transplantation, likely due, in part, to the impaired immune-suppression capacity of LSECs.

Pembrolizumab-caused polyradiculoneuropathy as an immune-related adverse event.

Immune-related adverse events (irAEs) commonly involve the gastrointestinal tract, endocrine glands, skin, and liver, and rarely the nervous system. The pathomechanism of irAEs in the nervous system is unclear, and so characterizing these severe toxic effects is a priority, even if irAEs are uncommon in the nervous system. Our patient presented subacute muscle weakness and dysesthesia with colitis as irAEs caused by pembrolizumab, one of the anti-programmed death-1 (PD-1) antibodies. Electromyography revealed abundant fibrillations and fasciculations of upper and lower extremities and severe reduction in motor unit potentials; however, antineutrophil cytoplasmic antibodies, rheumatoid factor, autoantibodies against Hu and Yo, and anti-ganglioside antibodies, such as GQ1b, were undetectable in the serum. Although he was treated with high-dose glucocorticoids, antibiotics, and a monoclonal anti-tumor necrosis factor alpha (TNFα) antibody, he developed colonic perforation. The total colorectal resection was performed, and the resected colon showed mucosal defect and perforation. He died of lung aspergillosis. Postmortem examination revealed CD8-positive lymphocyte infiltration around neurons of dorsal root ganglia. The sciatic nerve displayed the widening of myelin laminae and thinning of myelinated fibers but not a decrease in the density of myelinated nerve fibers. In the sural nerve, the density of myelinated fibers slightly decreased, and some fibers showed less densely myelinated laminae. Drug safety information, including previous randomized trials of anti-PD-1 and anti-cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) antibodies, showed that patients treated with anti-PD-1 antibodies appeared to have more frequent and severe peripheral neuropathies compared to those in patients who received anti-CTLA-4 antibodies (1.59% vs. 0.69%; Fisher exact test, P < 0.001; three severe events vs. zero severe events). The present results and drug safety information suggest that the pathomechanism of irAEs caused by anti-PD-1 antibodies is different from that by anti-CTLA-4 antibodies. The neurological irAEs might be clues to solving the pathomechanism of irAEs.

A novel model for predicting posthepatectomy liver failure based on liver function and degree of liver resection in patients with hepatocellular carcinoma.

BACKGROUND: The permissible liver resection rate for preventing posthepatectomy liver failure (PHLF) remains unclear. We aimed to develop a novel PHLF-predicting model and to strategize hepatectomy for hepatocellular carcinoma (HCC). METHODS: This retrospective study included 335 HCC patients who underwent anatomical hepatectomy at eight institutions between 2013 and 2017. Risk factors, including volume-associated liver-estimating parameters, for PHLF grade B-C were analyzed in a training set (n = 122) via multivariate analysis, and a PHLF prediction model was developed. The utility of the model was evaluated in a validation set (n = 213). RESULTS: Our model was based on the three independent risk factors for PHLF identified in the training set: volume-associated indocyanine green retention rate at 15 min, platelet count, and prothrombin time index (the VIPP score). The areas under the receiver operating characteristic curve of the VIPP scores for severe PHLF in the training and validation sets were 0.864 and 0.794, respectively. In both sets, the VIPP score stratified patients at risk for severe PHLF, with a score of 3 (specificity, 0.92) indicating higher risk. CONCLUSION: Our model facilitates the selection of the appropriate hepatectomy procedure by providing permissible liver resection rates based on VIPP scores.

A case of Turcot's syndrome type 1 with loss of immunoexpression of MSH6 in colon cancer and liver metastasis due to secondary somatic mutation in coding mononucleotide (C)8 tract: a case report.

BACKGROUND: Lynch syndrome (LS), which is known as a hereditary cancer syndrome, is distinguished by microsatellite instability, represented by the altered number of repetitive sequences in the coding and/or non-coding region. Immunohistochemical staining (IHC) of DNA mismatch repair (MMR) proteins (e.g., MLH1, MSH2, MSH6, and PMS2) has been recognized as an useful technique for screening of LS. Previous study has shown that the assessment of IHC, however, requires specific caution due to variable staining patterns even without germline mutations in MMR genes. CASE PRESENTATION: A 48-year-old man, who had been treated for anaplastic astrocytoma, was referred to our department for the precise examination of progressing anemia. Whole-body examination revealed two advanced carcinomas in descending colon and stomach. A hypo-vascular mass lesion was detected in liver as well. Pathological diagnosis (on surgical specimens) was poorly differentiated adenocarcinoma in descending colon, moderately differentiated tubular adenocarcinoma in stomach, and liver metastasis, which is possibly from colon. It was suspected that this case would be Turcot's syndrome-type-1 due to its specific family history having two cases of colon cancer within the second relatives. Pathogenic frameshift mutations in codon 618 of MLH1 gene was identified. Immunohistochemical analyses (IHC) demonstrated complete loss of MLH1 immuno-expression as well as of PMS2 except for those in brain tumor. Although frameshift mutation was not found in MSH6 gene, histological expression of MSH6 was patchy in primary colon carcinoma and was completely lost in the metastatic site in liver. MSH6 expression in gastric carcinoma, a coincidental cancer in this case, was intact. An abnormal (C)8 region was identified by the cloned PCR of colon and liver tumors but not from gastric cancer. Frameshift mutation in a (C)8 tract in exon 5 of the MSH6 gene was also detected in liver metastasis. CONCLUSION: This case supports a plausible mechanism, proposed by a previous literature, for the reduced expression of MSH6 in a somatic mutation manner, which might preferentially happen in colon cancer rather than in stomach carcinoma in MLH1/PMS2-deficient type of Turcot's syndrome type 1.

Laparoscopic versus open limited liver resection for hepatocellular carcinoma with liver cirrhosis: a propensity score matching study with the Hiroshima Surgical study group of Clinical Oncology (HiSCO).

BACKGROUND: Laparoscopic liver resection (LLR) has evolved as a safe and effective alternative to conventional open liver resection (OLR) for malignant lesions. However, LLR in cirrhotic patients remains challenging. This study analyzed the perioperative and oncological outcomes of LLR for hepatocellular carcinoma (HCC) with cirrhosis compared with OLR using propensity score matching. METHODS: A multicenter retrospective analysis of records of patients who underwent limited liver resection for HCC and were histologically diagnosed with liver cirrhosis between January 2009 and December 2017 in the eight institutions belonging to the Hiroshima Surgical study group of Clinical Oncology was performed. The patients were divided into two groups: the LLR and OLR groups. After propensity score matching, we compared clinicopathological features and outcomes. RESULTS: In total 256 patients with histological liver cirrhosis who underwent limited liver resection for HCC were included in this study; 58 patients had undergone LLR, and the remaining 198 patients OLR. The number of tumors was higher, tumor size was larger, and difficulty score was significantly higher in the OLR group before propensity matching. After the matching, the data of the well-matched 58 patients in each group were evaluated; the intraoperative blood loss was lower in the LLR group (p = 0.004), and incidence of the postoperative complications was significantly higher in the OLR group (p = 0.019). The duration of the postoperative hospital stay was significantly shorter in the LLR group (p < 0.001). There were no differences between two groups in overall survival and recurrent-free survival. CONCLUSIONS: LLR decreased the incidences of postoperative complications, shortened the duration of postoperative hospital stay. Thus, LLR is a safe and feasible procedure even in patients with cirrhosis.

Feasibility and efficacy of repeat laparoscopic liver resection for recurrent hepatocellular carcinoma.

BACKGROUND: Repeat hepatectomy is an acceptable treatment for recurrent hepatocellular carcinoma (HCC). However, repeat laparoscopic liver resection (LLR) has not been widely adopted due to its technical difficulty. This study aimed to assess the feasibility and efficacy of repeat LLR compared with repeat open liver resection (OLR) for recurrent HCC. METHODS: We performed 42 repeat OLR and 30 repeat LLR for cases of recurrent HCC between January 2007 and March 2018. This study retrospectively compared the patients' clinicopathological characteristics and operative and short-term outcomes including surgical time, intraoperative blood loss, duration of hospital stay, and postoperative complications between the two groups. RESULTS: There were no significant differences in patient characteristics between the two groups except in terms of Child-Pugh grade. The repeat LLR group had lower median intraoperative blood loss (100 mL vs. 435 mL; P = 0.001) and shorter median postoperative hospital stay (10 days vs. 14.5 days; P = 0.002). The other results including postoperative complications were comparable between the two groups. Further, comparison of two subpopulations of the repeat LLR group stratified by previous hepatectomy type (open or laparoscopic) or tumor location (segments 7 and 8 or other) revealed no significant differences in the postoperative clinical characteristics between them, although the morbidity rate tended to be higher in patients who underwent open hepatectomy for primary HCC than in patients who underwent laparoscopic hepatectomy. CONCLUSIONS: Repeat LLR for recurrent HCC is feasible and useful with good short-term outcomes although an appropriate patient selection seems to be necessary.

[MSI-H Small Bowel Cancer with Peritoneal Dissemination Successfully Treated with Pembrolizumab-A Case Report].

A 52-year-old man was diagnosed with small bowel adenocarcinoma(T4aN1M0, Stage ⅢA, according to the Japanese colorectal cancer classification)and treated with partial resection of the small bowel in June 2014. He also received adjuvant chemotherapy(XELOX: 8 courses)after surgery. Three and a half years after the operation, peritoneal dissemination recurred, and he received bevacizumab plus XELOX therapy. The regimen was adjusted to a total of 11 courses because of the disease progression. The primary lesion showed MSI-H. The patient was started on pembrolizumab therapy in April 2019. The tumor responded well to pembrolizumab(maximum therapeutic effect: PR, 31% reduction), but a new lesion appeared 6 months after the start of this regimen. He continued pembrolizumab therapy for 14 months without adverse events since it appeared to be clinically effective. Although MSI-H small bowel cancers are rare, accurate screening is essential to not miss the opportunity to administer pembrolizumab.

[A Case of Sigmoid Colon Cancer Recurrence at the Hand-Sewn Anastomosis Site Originated from Tumor Implantation].

We report a case of anastomotic recurrence following laparoscopic sigmoidectomy with hand-sewn anastomosis, which was attributable to the implantation of exfoliated cancer cells. A 78-year-old man diagnosed with early colon cancer underwent endoscopic submucosal dissection(ESD); however, ESD was suspended due to infiltrated muscle fibers. Subsequently, he underwent laparoscopic sigmoidectomy with hand-sewn anastomosis, accompanied by D3 lymph node dissection. Histopathological findings revealed a well-differentiated tubular adenocarcinoma, pT2(MP), tub1>tub2>por2, ly0, v1, PM0, DM0, RM0, N0M0, pStage Ⅰ. The follow-up CT 6 months after surgery, showed enhanced wall thickening and irregular surface of the sigmoid colon. Colonoscopy revealed a type 2 tumor located on the anastomotic line. Based on the diagnosis of anastomotic recurrence, the patient underwent partial colectomy. Histopathological findings were similar to those of the primary tumor and suggested implantation of exfoliated cancer cells as the origin of anastomotic recurrence. Cancer cells had infiltrated all layers. In conclusion, we recommend the performance of appropriate operative procedures to prevent anastomotic recurrence, such as the cleaning of the anastomosed intestinal tract. Careful follow-up in colon cancer patients is of the utmost importance and the risk of anastomotic recurrence should always be considered.

[Two Cases of Colorectal Liver Metastasis with Localized Biliary Dilatation].

We encountered 2 cases of colorectal liver metastasis with biliarydilatation mimicking cholangiocarcinoma. Case 1: A 70- year-old male patient, who was diagnosed with colorectal cancer and underwent transverse colectomy3 years prior, was preoperativelydiagnosed with cholangiocarcinoma with biliarydilatation of the medial and lateral segments. He underwent left hemi-hepatectomy. The pathological diagnosis was colorectal liver metastasis with intra-biliarytumor thrombosis. Case 2: A 67-year-old male patient was diagnosed with descending colon cancer and cholangiocarcinoma with biliarydilatation of the medial segment. He underwent left hemi-colectomyand left hemi-hepatectomy. The pathological diagnosis was descending colon cancer and colorectal liver metastasis with biliaryinfiltration. The immunopathological findings showed double positivityfor CK20 and CDX2 antibodies and negativityfor CK7 antibodyin these cancer lesions.

[A Case of Advanced Gastric Cancer with Para-Aortic Lymph Node Metastasis Treated with Conversion Surgery after S-1 plus Oxaliplatin Chemotherapy].

A 71-year-old man was diagnosed as having Type 2 gastric cancer(tub2, HER2-negative). Abdominal computed tomography( CT)revealed bulky metastatic lymph nodes around the stomach and para-aorta(No. 16a2, b1). Our clinical diagnosis was cT4a(SE)N+M1(PAN), cStage Ⅳb, and SOX therapy was immediately administered. After 3 courses of chemotherapy, the treatment effect was PR, and after 6 courses, the patient was diagnosed with ycT2(MP)N0M0, ycStageⅠB. No Grade 2 or higher adverse events were observed during chemotherapy. At this stage, we determined that radical resection was feasible; thus, distal gastrectomy and D3 dissection(para-aortic lymph node dissection)were performed. No cancer cells were found in the primary lesion on histopathology. The histological response of the primary lesion was Grade 3, and the lymph node was Grade 2b. On follow-up observation, the patient is alive without tumor recurrence at 1 year postoperatively.