[A Case of Conversion Surgery after SOX plus Nivolumab for Unresectable Advanced Gastric Cancer].

A 63-year-old woman came to our hospital complaining of anemia and weight loss. The abdominal CT showed wall thickening from the upper to lower the body of stomach, and peritoneal dissemination. The EGD revealed a type 3 large tumor extending about 2/3 of the circumference. Adenocarcinoma was detected as a result of biopsy. The patient was diagnosed with unresected gastric cancer(cT4aN+M1, cStage Ⅳ). SOX plus nivolumab was selected as a first-line chemotherapy because of HER2 expression negative. Symptoms such as diarrhea developed, and the treatment was completed until 5 courses. Laparoscopic distal gastrectomy was performed after the disappearance of abdominal dissemination by CT scan and PET. Pathological examination revealed cancer cells were completely disappeared in the tumor, regional lymph nodes and white nodules in the peritoneum, and final diagnosis was ypT0N0M0, ypStage 0(histological effect determination is Grade 3). Six months after the operation, the patient has been free of recurrence.

Double cancer of primary hepatic angiosarcoma and hepatocellular carcinoma treated with atezolizumab plus bevacizumab.

AIM: Primary hepatic angiosarcoma (PHA) is extremely rare, and its imaging findings are similar to those of other liver tumors including hepatocellular carcinoma (HCC). Here, we report a case of hepatitis C virus (HCV)-related HCC followed by PHA that showed remarkable clinical response to atezolizumab plus bevacizumab (Atezo/Bev) therapy. CASE PRESENTATION: A 78-year-old man with recurrent HCC had a liver tumor with lymphadenopathy. Although considered as HCC recurrence, microscopic examination of the resected liver and lymph node showed PHA. Three months later, a solitary lung nodule was newly detected and subsequently resected. The pathological diagnosis was poorly differentiated HCC. Therefore, the patient was finally diagnosed with double cancer of PHA and HCC. Thereafter, he developed a new liver tumor with lymphadenopathy and received Atezo/Bev therapy. Liver tumor biopsy was carried out before the treatment. The pathological diagnosis was angiosarcoma. The patient showed a partial response after two courses of Atezo/Bev therapy. CONCLUSION: To our best knowledge, this report is the first case to present HCV-related HCC followed by PHA and to show that Atezo/Bev therapy is beneficial for PHA.

Phase I study of a novel therapeutic vaccine as perioperative treatment for patients with surgically resectable hepatocellular carcinoma: The YCP02 trial.

AIM: Developing effective adjuvant therapies is essential for improving the surgical outcomes in patients with hepatocellular carcinoma (HCC). Immunotherapy against HCC has become a promising strategy; however, only approximately 30% of all HCC patients respond to immunotherapy. Previously, we generated the novel therapeutic vaccine comprising multi-human leukocyte antigen-binding heat shock protein 70/glypican-3 peptides with a novel adjuvant combination of hLAG-3Ig and poly-ICLC. We also confirmed the safety of this vaccination therapy, as well as its capacity for the effective induction of immune responses in a previous clinical trial. METHODS: In this phase I study, we administered this vaccine intradermally six times before surgery, and 10 times after surgery to patients with untreated, surgically resectable HCC (stage II to IVa). The primary end-points of this study were the safety and feasibility of this treatment. We also analyzed the resected tumor specimens pathologically using hematoxylin-eosin staining and immunohistochemistry for heat shock protein 70, glypican 3, CD8 and programmed death-1. RESULTS: A total of 20 human leukocyte antigen-matched patients received this vaccination therapy with an acceptable side-effect profile. All patients underwent planned surgery without vaccination-related delay. Immunohistochemical analyses revealed that potent infiltration of CD8+ T cells into tumors with target antigen expression was observed in 12 of 20 (60%) patients. CONCLUSIONS: This novel therapeutic vaccine was safe as perioperative immunotherapy for patients with HCC, and has the potential to strongly induce CD8+ T cells infiltration into tumors.

[A Case of Early Pancreatic Cancer Diagnosed from the Finding of Partial Pancreatic Parenchymal Atrophy].

A man in his 80s was referred to our hospital for further examination of partial pancreatic atrophy that was detected incidentally. Various imaging examinations including CT, MRI, and EUS did not reveal any obvious abnormal findings other than the partial pancreatic atrophy. However, cytological examination of serial pancreatic juice aspiration showed atypical cells. The presence of pancreatic intraepithelial carcinoma in the atrophy site was considered, and the patient underwent laparoscopic distal pancreatectomy. Pathological examination of the excised specimen confirmed the presence of high-grade pancreatic intraepithelial neoplasia consistent with the atrophy site, and the patient was diagnosed with pTisN0M0, Stage 0 pancreatic cancer. For the detection of early pancreatic cancer, it is important to be aware of partial pancreatic atrophy on imaging studies.

Immune Evasion of Hepatoma Cancer Stem-Like Cells from Natural Killer Cells.

BACKGROUND: Poor prognosis in liver cancer is due to its high frequency of intrahepatic metastasis. Cancer stem-like cells (CSLCs), which possess the properties of stemness, tumor initiation capability, and resistance to therapy, also exhibit metastatic potential. Immune surveillance plays an important role in the accomplishment of metastasis. Herein, the property of immune evasion in CSLCs was investigated. METHODS: Sphere cells were induced as CSLCs using a sphere induction medium containing neural survival factor-1. The expression of genes involved in immune evasion was determined using RNA-sequencing for sphere and parental cells followed by validation using flow cytometric analysis and ELISA. Susceptibility to natural killer (NK) cell-mediated cytotoxicity was examined by a chromium release assay. A xenograft model using BALB/c nu/nu mice was used to assess tumor growth. Gene set enrichment analysis was performed for interpreting RNA sequencing. RESULTS: The cell surface expressions of PD-L1, PD-L2, and CEACAM1 were upregulated and those of ULBP1 and MICA/MICB were downregulated in SK-sphere, CSLCs derived from SK-HEP-1, compared with that in parental cells. Levels of soluble MICA were elevated in conditioned medium from SK-sphere. Expression of HLA class I was not downregulated in SK-sphere. The susceptibilities to NK cell-mediated killing and secreted perforin were significantly lower in both CSLCs derived from SK-HEP-1 and HLE than in parental cells. Tumors formed upon inoculation of SK-sphere in immunodeficient mice harboring NK cells were larger than those formed upon inoculation of parental cells. CONCLUSION: Human hepatoma cell line-derived CSLCs may possess immune evasion properties, especially from NK cell-mediated immunity.

Elevated expression of RAB3B plays important roles in chemoresistance and metastatic potential of hepatoma cells.

BACKGROUND: Cancer stem cells (CSCs) are thought to play important roles in carcinogenesis, recurrence, metastasis, and therapy-resistance. We have successfully induced cancer stem-like sphere cells (CSLCs) which possess enhanced chemoresistance and metastatic potential. To enable the development of targeted therapy against CSLCs, we identified a gene responsible for this phenotype in CSLC. METHODS: Human hepatoma cell line SK-HEP-1 was used for CSLC induction with a unique sphere inducing medium, and HuH-7 cells were used as non-sphere forming cells in the same condition. RNA-sequencing was performed followed by validation with quantitative RT-PCR and western blotting. Knockdown experiments were done by using CRISPR-Cas9 genome-editing, and the rescue experiments were performed using the expressing plasmid vector. Chemoresistance and liver metastasis of the cells, was studied following the splenic injection of cells to severely immune deficient mice and evaluated using the MTS assay. Quantification of exosomes in the medium was done using ELISA. RESULTS: RAB3B was identified as an up-regulated gene in both CSLCs and prognostically poor hepatocellular carcinoma (HCC) by RNA-sequencing. RAB3B-KD cells showed altered CSLC phenotypes such as sphere formation, chemoresistance, and metastatic potentials, and those were rescued by RAB3B complementation. Increased exosome secretion was observed in CSLCs, and it was not observed in the RAB3B-KD cells. In addition, the RAB3B expression correlated with the expression of ABCG2, APOE, LEPR, LXN, and TSPAN13. CONCLUSION: The up regulation of RAB3B may play an important role in the chemoresistance and metastatic potential of CSLCs.

CD4 and FOXP3 as predictive markers for the recurrence of T3/T4a stage II colorectal cancer: applying a novel discrete Bayes decision rule.

BACKGROUND: We recently reported the relapse-free survival (RFS) significance of the combination of CD4+ and forkhead box P3+ (FOXP3) T-cell densities identified by immunohistochemistry in patients with stage I, II, and III colorectal cancer (CRC) who underwent curative resections. This study was designed to determine the optimal combination of markers that predict recurrence in patients with T factors of T3/T4a stage II CRC by applying a novel Bayes decision rule. METHODS: Using 137 cancer tissue specimens from T3/T4a stage II patients, 12 clinicopathologic and immune factors were analysed as predictive candidates for recurrence. RESULTS: Our study showed that the combination of low CD4+ and low FOXP3+ T-cell densities resulted in extremely poor RFS. CONCLUSIONS: Adjuvant chemotherapy may be considered for patients with a combination of low CD4+ and low FOXP3+ T-cell densities. The discovery of this new prognostic indicator is important for the appropriate management of patients undergoing curative resection for T3/T4a stage II CRC.

[Surgical Resection of Gastric GIST Liver Metastasis with Giant Cystic Mass-A Case Report].

The patient is a woman in her 80s who underwent a partial gastrectomy for a gastric GIST 14 years ago. This time, she presented our department with upper abdominal distention and computed tomography revealed an 18 cm-sized cystic lesion in the left lobe of the liver. Since a nodule enhancement was observed in the cyst, malignant disease such as hepatic cystadenocarcinoma could not be ruled out and surgical resection was performed. Pathological examination revealed liver metastasis of gastric GIST. In Japan, only 14 cases have been reported showing such late recurrence with liver metastasis more than 10 years after resection of a primary tumor, including our case. In addition, the cystic finding in this case made preoperative diagnosis difficult because a needle biopsy could not be performed to obtain a pathological diagnosis.

Novel adjuvant dendritic cell therapy with transfection of heat-shock protein 70 messenger RNA for patients with hepatocellular carcinoma: a phase I/II prospective randomized controlled clinical trial.

INTRODUCTION: A proteomic analysis of hepatocellular carcinoma (HCC) has revealed that Heat Shock Protein 70 (HSP70) is among the cancer antigen proteins of HCC. Moreover, we confirmed that HSP70 was highly expressed in HCC by immunohistochemical staining. Based on these results, we developed an HSP70 mRNA-transfected dendritic cell (DC) therapy for treating unresectable or recurrent HCC, and the phase I trial was completed successfully. Thus, we aimed to investigate the safety and efficacy of this therapy as a postoperative adjuvant treatment after curative resection for HCC to prevent recurrence by conducting a phase I/II randomized controlled clinical trial. METHODS: Patients (n = 45) with resectable HCC of stages II-IVa were registered and randomly assigned into two groups (DC group: 31 patients, control group: 14 patients) before surgery. The primary endpoint was disease-free survival (DFS), and the secondary endpoints were safety and overall survival. The DC therapy was initially administered at approximately 1 week after surgery, and twice every 3-4 weeks thereafter. RESULTS: No adverse events specific to the immunotherapy were observed in the DC group. There was no difference in DFS between the DC and control groups (p = 0.666). However, in the subgroup with HSP70-expressing HCC, DFS of the DC group tended to be better (p = 0.090) and OS of the DC group was significantly longer (p = 0.003) than those of the control group. CONCLUSION: The HSP70 mRNA-transfected DC therapy was performed safely as an adjuvant therapy. The prognosis of HSP70-expressing HCC cases could be expected to improve with this therapy.

Laparoscopic resection reduces superficial surgical site infection in liver surgery.

BACKGROUND: Laparoscopic liver resection is beneficial compared to open liver resection. This study aimed to evaluate whether laparoscopic liver resection could reduce postoperative infections. METHODS: This study included 125 and 115 patients with liver tumors who underwent open and pure laparoscopic partial resections or left lateral sectionectomies, respectively. Propensity score matching and stabilized inverse probability of treatment weighting were carried out to compare the postoperative infectious complication rates between the two groups. RESULTS: Patients with tumors located in Couinaud segment 1, 7, or 8; with tumors adjacent to major vessels; or who underwent repeated resections were more likely to receive open resection. After propensity score matching, the superficial incisional surgical site infection rate tended to be lower in the laparoscopic liver resection group than in the open liver resection group. Moreover, overall infectious complication rate and superficial incisional surgical site infection rate were lower in the laparoscopic group (the cohort formed by the stabilized inverse probability of treatment weighting). CONCLUSIONS: Using the laparoscopic approach for partial resections and left lateral sectionectomies for liver tumors, the superficial incisional surgical site infection rate could be reduced.

Hepatic artery resection and reconstruction using the right gastroepiploic artery during pancreaticoduodenectomy in advanced pancreatic cancer.

PURPOSE: Surgical resection is the only curative treatment for pancreatic cancer. Arterial resection and reconstruction during pancreaticoduodenectomy for advanced pancreatic cancer remain controversial due to a high rate of complications. METHODS: We report two cases of pancreatic cancer with hepatic artery resection and reconstruction using the right gastroepiploic artery during pancreaticoduodenectomy after neoadjuvant therapy. RESULTS: The patients underwent pancreaticoduodenectomy with resection of the right hepatic and common hepatic arteries. Achieving direct anastomosis was difficult; therefore, we planned hepatic artery reconstruction using the right gastroepiploic artery. We performed the reconstruction using an interrupted suture with end-to-end anastomosis. The first patient developed a postoperative pancreatic fistula, while the postoperative course of the second patient was uneventful. However, there were no adverse events related to the arterial reconstruction. R0 resection was achieved, and postoperative computed tomography revealed good patency of the reconstructed artery. CONCLUSION: Hepatic artery reconstruction using the right gastroepiploic artery in pancreatic cancer might be technically safe and might become one of the alternative options.

[A Resected Case of Advanced Lower Rectal Cancer with Neoadjuvant Chemotherapy by FOLFOXIRI plus Cetuximab].

Although the current standard of care for patients with lower rectal cancer in Japan includes total mesorectal resection with lateral lymph node dissection, postoperative local and distant recurrence rates are high. Multidisciplinary treatment is important to improve the prognosis. A man in his 30s was diagnosed with lower rectal cancer due to bloody stool and referred to our department. He was diagnosed as cT3N3M0, cStage Ⅲc with right obturator lymph node metastasis. Four courses of neoadjuvant chemotherapy(NAC)with FOLFOXIRI plus cetuximab were performed. Because Grade 3 neutropenia was observed in the first cycle(CTCAE v5.0), pegfilgrastim was administered in the second and subsequent cycles, and NAC was completed without dose reduction. The patient underwent laparoscopy-assisted intersphincteric rectal resection and D3+rtLD2 dissection. Histopathological resection margins were negative, and the resection was R0. Lymph node metastasis was found only in No. 263d-rt, and the pathological diagnosis was ypT3N3M0, pStage Ⅲc. Histological evaluation of response to treatment was Grade 2. The postoperative course was good and the patient was discharged on postoperative day 15. The patient received 8 courses of adjuvant chemotherapy with mFOLFOX6 from the 7th postoperative week and is alive and recurrence-free 6 months after surgery.

[A Case of Intrahepatic Cholangiocarcinoma in the Elderly Patient with Curative Resection after Neoadjuvant Chemotherapy].

An 80 year-old woman with anorexia and jaundice was diagnosed with mass-forming intrahepatic cholangiocarcinoma, lymph node metastasis, common hepatic duct strictures, and obstructive jaundice. PET-CT showed FDG accumulation in the primary lesion(SUVmax 19.0)and swollen lymph nodes. Her ADL and major organ functions were judged to be sufficient for treatment. After treatment for jaundice, she received a total of 6 courses of gemcitabine, cisplatin plus S-1(GCS)therapy as neoadjuvant chemotherapy(NAC). Her first treatment was an 80% dose of GCS, but she was subsequently diagnosed with Grade 4 thrombocytopenia(CTCAE v5.0). The dose of gemcitabine was further reduced, and no adverse events of Grade 3 or higher were observed thereafter. After NAC, PET-CT showed decreased FDG accumulation in the primary lesion(SUVmax 3.3)and normalization of FDG accumulation in the lymph nodes. Extended right hepatectomy and biliary reconstruction were performed as radical resection(R0). The final diagnosis was pT2, N0, M0, Stage Ⅱ. After hepatectomy, her anorexia and poor ADL persisted. She was discharged to her home 151 days after her surgery.

[A Case of Pseudo-Meigs' Syndrome Caused by Ovarian Metastasis from Colon Cancer].

This case pertains to a female patient in her 60s who was diagnosed with carcinoma in the cecum with lung, ovarian, and peritoneal metastases. She complained of abdominal distension and poor feeding because her ascites and ovarian metastasis worsened 18 months after chemotherapy initiation. Repeated cytologic examination of the ascitic fluid revealed no malignant cells. Therefore, Pseudo-Meigs' syndrome was suspected. Bilateral salpingo-oophorectomy was performed as palliative surgery because of the patient's reduced capacity to perform activities of daily living(ADL)due to ascites. After palliative surgery, her ascites disappeared, and she was able to better perform ADL. Further, chemotherapy was resumed. The patient remains well 10 months after surgery. This case highlights the importance of considering Pseudo-Meigs' syndrome in patients with massive ascites and ovarian metastasis, because surgical resection can improve their quality of life.

[A Case of Combined Hepatocellular Carcinoma and Cholangiocarcinoma with Multidisciplinary Treatment Including Lenvatinib].

A 49-year-old man came to our department for the purpose of scrutinizing liver tumor. CA19-9 and CA125 increased, and AFP and PIVKA-Ⅱ were within the normal range. CT showed a large number of early ring enhanced tumor, and a tumor thrombus in the left branch of the portal vein. Tumor biopsy revealed adenocarcinoma. Chemotherapy(gemcitabine, cisplatin plus S-1: GCS)was performed for intrahepatic cholangiocarcinoma(r/o combined hepatocellular carcinoma and cholangiocarcinoma). Lenvatinib was administered because portal vein tumor thrombus and PIVKA-Ⅱ increased after GCS therapy. Two months later, CA19-9 and PIVKA-Ⅱ were decreased and portal vein tumor thrombus was shrunk. Extended left hepatectomy was performed for the purpose of disease control. Histopathological examination revealed some hepatocellular carcinoma components in intrahepatic cholangiocarcinoma. Tumor thrombus was vitrified and necrotic. After hepatectomy, administration of lenvatinib was continued for the residual lesion, and no significant tumor growth was observed.

[A Case of Anastomotic Recurrence of Rectal Cancer Treated by Laparoscopic Total Pelvic Exenteration after Neoadjuvant Chemoradiation].

Patient is 69-year-old man, who underwent a high anterior resection with laparoscopic support for rectal cancer. The patient was diagnosed with anastomotic recurrent rectal cancer after 14 months after surgery. The pelvic MRI scan showed invasion of the prostate and seminal vesicles, so NACRT was performed. Tumors were found to have decreased in size, although there was still some residual invasion of the prostate and seminal vesicle. Laparoscopic total pelvic exenteration (Lap-TPE), and combined excision of the anal elevator muscle and bladder were performed. Preoperative diagnosis was ycT4b, N0, M0, ycStage Ⅱ, and pathological diagnosis was pT4b (prostate and seminal vesicles), INF b, Ly2, v2, Pn1b, pPM0, pDM0, pRM0, and pN0. Laparoscopic surgery allowed to operate safely, with minimal blood loss and a good field of vision. After postoperative adjuvant chemotherapy, lung and liver metastasis appeared after 6 months after surgery, but there was no local recurrence. The patient is treated with chemotherapy, and the metastases are under control. The patient is survive 17 months after Lap-TPE.

[A Case of Gastrointestinal Stromal Tumor of the Lower Rectum That Enabled Minimally Invasive Surgery with Imatinib Mesylate as Neoadjuvant Chemotherapy].

A 67-year-old woman was admitted with melena. A colonoscopy detected a 50 mm submucosal tumor close to the dentate line. We diagnosed the rectal gastrointestinal stromal tumor by EUS-FNA. With the expectation of tumor shrinkage and strong hope of the patient, we started imatinib mesylate as neoadjuvant chemotherapy. A CT scan after 3 months after administration of imatinib mesylate showed the reduction of the size to 35 mm. We operated transanal endoscopic surgery considering the localization of the tumor. From histopathological findings, the tumor was low risk in the modified-Fletcher classification, and low risk in the Miettinen classification. Eight months after the operation, no recurrence was observed without further adjuvant chemotherapy. In this case, we were able to resect the tumor without injuring the film of tumor by operating transanal endoscopic surgery, because of tumor shrinkage with imatinib mesylate as neoadjuvant chemotherapy. I considered that using imatinib mesylate preoperatively was contributed to minimally invasive surgery.

A phase I study of multi-HLA-binding peptides derived from heat shock protein 70/glypican-3 and a novel combination adjuvant of hLAG-3Ig and Poly-ICLC for patients with metastatic gastrointestinal cancers: YNP01 trial.

BACKGROUND: This phase I study aimed to evaluate the safety, peptide-specific immune responses, and anti-tumor effects of a novel vaccination therapy comprising multi-HLA-binding heat shock protein (HSP) 70/glypican-3 (GPC3) peptides and a novel adjuvant combination of hLAG-3Ig and Poly-ICLC against metastatic gastrointestinal cancers. METHODS: HSP70/GPC3 peptides with high binding affinities for three HLA types (A*24:02, A*02:01, and A*02:06) were identified with our peptide prediction system. The peptides were intradermally administered with combined adjuvants on a weekly basis. This study was a phase I dose escalation clinical trial, which was carried out in a three patients' cohort; in total, 11 patients were enrolled for the recommended dose. RESULTS: Seventeen patients received this vaccination therapy without dose-limiting toxicity. All treatment-related adverse events were of grades 1 to 2. Peptide-specific CTL induction by HSP70 and GPC3 proteins was observed in 11 (64.7%) and 13 (76.5%) cases, respectively, regardless of the HLA type. Serum tumor marker levels were decreased in 10 cases (58.8%). Immunological analysis using PBMCs indicated that patients receiving dose level 3 presented with significantly reduced T cell immunoglobulin and mucin-domain containing-3 (TIM3)-expressing CD4 + T cells after one course of treatment. PD-1 or TIM3-expressing CD4 + T cells and T cell immunoreceptor with immunoglobulin and ITIM domains (TIGIT)-expressing CD8 + T cells in PBMCs before vaccination were negative predictive factors for survival. CONCLUSIONS: This novel peptide vaccination therapy was safe for patients with metastatic gastrointestinal cancers.

Serum LOX-1 is a novel prognostic biomarker of colorectal cancer.

BACKGROUND: Colorectal cancer is the third most common cancer worldwide. If biomarkers can be identified in liquid biopsy, diagnosis and treatment can be optimized even when cancerous tissues are not available. The purpose of this study was to identify proteins from liquid biopsy that would be useful as markers of poor prognosis. METHODS: First, we comprehensively analyzed serum proteins to identify potential biomarkers and focused on serum lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1). The relationship between LOX-1 and the prognosis of patients with colorectal cancer has not been reported. Next, we validated this marker using serum samples from 238 patients with colorectal cancer by ELISA and 100 tissue samples by immunohistochemical staining. RESULTS: The optimal cut-off value of serum LOX-1 was 538.7 pg/mL according to time-dependent receiver operating characteristics curve analysis. The overall survival of patients with high levels of serum LOX-1 was significantly poorer than that of individuals with low levels of LOX-1 in the training and test datasets. In multivariate analysis for overall survival, serum LOX-1 was an independent prognostic factor identified in liquid biopsy (hazard ratio = 1.729, p = 0.027). The prognosis of patients with high LOX-1 expression in tumor tissues was significantly poorer than that of individuals with low expression (p =0.047 ). Additionally, inflammatory factors such as white blood cell count, C-reactive protein level, neutrophil/lymphocyte ratio, and monocyte/lymphocyte ratio were significantly higher in the group with high serum LOX-1 levels. CONCLUSIONS: Serum LOX-1 might be a useful biomarker of poor prognosis in colorectal cancer.

[A Case of Primary Liposarcoma of Pancreas Difficult to Diagnose Preoperatively].

The patient was a woman in her 80s. Operative treatment was performed for papillary thyroid cancer(pT3N0M0)13 years ago. A follow-up CT scan 1 year ago revealed a skin, lung, and lymph node metastasis. At the same time, a tumor with a size of 24 mm was initially observed in the tail of the pancreas, which was considered to be pancreatic metastasis of thyroid papillary cancer and was followed up. Only the pancreatic lesions tended to gradually increase, although other lesions did not increase. Therefore, the patient was referred to our department. It was difficult to diagnose preoperatively. Thus, diagnostic and therapeutic laparoscopic distal pancreatectomy with splenectomy was performed. The pathological diagnosis was dedifferentiated liposarcoma. Postoperatively, a Grade B pancreatic fistula was observed, but the patient recovered conservatively and was discharged on postoperative day 55. Primary liposarcoma of the pancreas is extremely rare, and few cases have been reported. Primary liposarcoma of the pancreas is very difficult to diagnose preoperatively by only diagnostic imaging.