Prognostic value of neutrophil to lymphocyte ratio in patients with advanced pancreatic ductal adenocarcinoma treated with systemic chemotherapy.

OBJECTIVES: Although systemic chemotherapy for pancreatic ductal adenocarcinoma (PDAC) has made progress, ensuring long-term survival remains difficult. There are several reports on the usefulness of neutrophil-to-lymphocyte ratio (NLR) in predicting the prognosis of PDAC, but few reports in systemic chemotherapy. We hereby investigated the usefulness of NLR in systemic chemotherapy for PDAC. MATERIALS AND METHODS: A retrospective study was conducted on patients with advanced PDAC treated with first-line systemic chemotherapy. Cox regression hazards models were performed to analyze the association between baseline patient characteristics and the initial treatment response, and overall survival (OS). RESULTS: A total of 60 patients with PDAC were enrolled. At baseline, there were significant differences in NLR and carbohydrate antigen 19-9 (CA19-9), as well as the selection rate of combination chemotherapy, between patients with partial response or stable disease and those with progressive disease. Univariate and multivariate analysis showed that NLR < 3.10, combination chemotherapy, and CA19-9 < 1011 U/mL were significant and independent predictive factors of the initial treatment response. Meanwhile, NLR < 3.10 and combination chemotherapy were independently associated with longer OS. Moreover, OS was significantly prolonged in patients with NLR < 3.10, regardless of whether combination chemotherapy or monotherapy. Patients with NLR < 3.10 at baseline had a significantly higher conversion rate to third-line chemotherapy and a longer duration of total chemotherapy. CONCLUSIONS: This study suggests that NLR may be a useful marker for predicting the initial treatment response to first-line chemotherapy and the prognosis for patients with advanced PDAC.

Laparoscopic median arcuate ligament section for median arcuate ligament compression syndrome initially detected as splenic infarction: a case report.

BACKGROUND: Median arcuate ligament compression syndrome (MALS) causes upper abdominal pain and at times hemodynamic abnormalities in the pancreaticoduodenal region. Herein, we present a case of a 70 year-old man, initially diagnosed with splenic infarction and was successfully treated laparoscopically. CASE PRESENTATION: A 70-year-old man with abdominal pain admitted to our hospital. Abdominal-enhanced computed tomography revealed a poorly contrasted area in the spleen and stenosis at the root of the celiac artery. Arterial dilatation was observed around the pancreaticoduodenal arcade, however, no obvious aneurysm formation or arterial dissection was observed. Abdominal-enhanced magnetic resonance imaging indicated the disappearance of the flow void at the root of the celiac artery. The patient had no history of atrial fibrillation and was diagnosed with splenic infarction due to median arcuate ligament compression syndrome. We performed a laparoscopic median arcuate ligament section with five ports. Intraoperative ultrasonography showed a retrograde blood flow in the common hepatic artery and the celiac artery. After releasing the compression, the antegrade blood flow from the celiac artery to the splenic artery, and the common hepatic artery were visualized using intraoperative ultrasonography. The postoperative course of the patient was uneventful, and he was discharged on postoperative day 9. Postoperative computed tomography a month after surgery revealed no residual stenosis of the celiac artery or dilation of the pancreaticoduodenal arcade. Furthermore, the poorly contrasted area of the spleen improved. CONCLUSIONS: Reports indicate that hemodynamic changes in the abdominal visceral arteries due to median arcuate ligament compression are related to the formation of pancreaticoduodenal aneurysms. In this case, median arcuate ligament compression syndrome caused splenic infarction by reducing blood flow to the splenic artery.

Tenascin C in pancreatic cancer-associated fibroblasts enhances epithelial mesenchymal transition and is associated with resistance to immune checkpoint inhibitor.

Tenascin C (TNC) is an extracellular matrix glycoprotein that is highly expressed in cancer stroma and is associated with tumor progression in pancreatic adenocarcinoma (PAAD). In this study, we aimed to investigate the potential involvement of TNC in the response to immune checkpoint inhibitors (ICI) among PAAD patients. Transcriptomic profiles were obtained from public databases and analyzed to compare TNC mRNA levels between tumor and normal tissues. Bioinformatic programs were used to predict paracrine communications between cancer cells and cancer-associated fibroblasts (CAFs), and the Tumor Immune Dysfunction and Exclusion (TIDE) score was calculated to predict response to ICI treatment in PAAD patients. An independent immunotherapeutic cohort was used to validate the clinical impact of the signatures. Results showed that TNC mRNA levels were significantly upregulated in tumors compared to normal tissues in PAAD, and patients with high TNC expression had significantly shorter overall survival than those with low TNC expression (P = 0.0125). TNC was predominantly expressed in CAFs of PAAD patients and was found to potentially enhance the epithelial-mesenchymal transition (EMT) of cancer cells via integrin receptors, contributing to resistance to ICI treatment. Patients with high TNC expression and high ITGαV or ITGB3 expression were associated with poor response to ICI therapy. In conclusion, these findings suggest that TNC-high CAFs play a crucial role in tumor progression and resistance to ICI therapy in PAAD patients, and targeting TNC and its interactions with cancer cells may provide a potential strategy for improving the efficacy of ICI therapy in PAAD.

Prediction of postoperative complications after hepatectomy with dynamic monitoring of central venous oxygen saturation.

BACKGROUND: The usefulness of static monitoring using central venous pressure has been reported for anesthetic management in hepatectomy. It is unclear whether intra-hepatectomy dynamic monitoring can predict the postoperative course. We aimed to investigate the association between intraoperative dynamic monitoring and post-hepatectomy complications. Furthermore, we propose a novel anesthetic management strategy to reduce postoperative complication. METHODS: From 2018 to 2021, 93 patients underwent hepatectomy at our hospital. Fifty-three patients who underwent dynamic monitoring during hepatectomy were enrolled. Flo Trac system was used for dynamic monitoring. The baseline central venous oxygen saturation (ScvO2) was defined as the average ScvO2 for 30 min after anesthesia induction. ScvO2 fluctuation (ΔScvO2) was defined as the difference between the baseline and minimum ScvO2. Postoperative complications were evaluated using the comprehensive complication index (CCI). RESULTS: Patients with ΔScvO2 ≥ 10% had significantly higher CCI scores (0 vs. 20.9: p = 0.043). In univariate analysis, patients with higher CCI scores demonstrated significantly higher preoperative C-reactive protein-to-lymphocyte ratio (7.51 vs. 24.49: p = 0.039), intraoperative bleeding (105 vs. 581 ml: p = 0.008), number of patients with major hepatectomy (4/45 vs. 3/8: p = 0.028), and number of patients with ΔScvO2 ≥ 10% (11/45 vs. 6/8; p = 0.010). Multivariate logistic regression analysis revealed that ΔScvO2 ≥ 10% (odds ratio: 9.53, p = 0.016) was the only independent predictor of elevated CCI. CONCLUSIONS: Central venous oxygen saturation fluctuation during hepatectomy is a predictor of postoperative complications. Anesthetic management based on intraoperative dynamic monitoring and minimizing the change in ScvO2 is a potential strategy for decreasing the risk of post-hepatectomy complications.

The cholinesterase and C-reactive protein score is a potential predictor of pseudoaneurysm formation after pancreaticoduodenectomy in patients with soft pancreas.

BACKGROUND: Pseudoaneurysm (PA) rupture after pancreaticoduodenectomy (PD) is a life-threatening complication. Most PA cases originate from postoperative pancreatic fistulas (POPFs). Although several risk factors for POPF have been identified, specific risk factors for PA formation remain unclear. Therefore, we retrospectively analyzed PD cases with soft pancreas and proposed a novel strategy for early detection of PA formation. METHODS: Overall, 120 patients underwent PD between 2010 and 2020 at our institution; of these, 65 patients with soft pancreas were enrolled. We evaluated the clinicopathological factors influencing PA formation and developed a risk score to predict PA formation. RESULTS: In total, 11 of the 65 patients developed PAs (PA formation group: PAG), and 8 of these 11 PAs ruptured. The median time to PA formation was 15 days, with a minimum of 5 days. The PAG was significantly older than the non-PA formation group, were predominantly men, and had comorbid diabetes mellitus. Pre- and intra-operative findings were similar between the two groups. Importantly, no significant differences were found in postoperative drain amylase levels and total drain amylase content. Cholinesterase and C-reactive protein (CRP) levels on postoperative day (POD) 3 were significantly different between the two groups. Multivariate analysis showed that cholinesterase ≤ 112 U/L and CRP ≥ 16.0 mg/dl on POD 3 were independent predictors of PA formation. CONCLUSIONS: Decreased cholinesterase and elevated CRP on POD 3 (Cho-C score) are useful predictors of PA formation in cases with soft pancreas. In such cases, periodic computed tomography evaluations and strict drain management are necessary to prevent life-threatening hemorrhage.

Phosphatidylcholine in bile-derived small extracellular vesicles as a novel biomarker of cholangiocarcinoma.

BACKGROUND: Owing to the lack of definite diagnostic modalities, it is challenging to distinguish malignant cases of cholangiocarcinoma (CCA), which often causes biliary tract obstruction, from benign ones. Here, we investigated a novel lipid biomarker of CCA in bile-derived small extracellular vesicles (sEVs) and developed a simple detection method for clinical application. METHODS: Bile samples from seven patients with malignant diseases (hilar CCA = 4, distal CCA = 3) and eight patients with benign diseases (gallstones = 6, primary sclerosing cholangitis = 1, autoimmune pancreatitis = 1) were collected through a nasal biliary drainage tube. sEVs were isolated via serial ultracentrifugation and characterized using nanoparticle tracking analysis, transmission electron microscopy, and immunoblotting (with CD9, CD63, CD81, and TSG101). Comprehensive lipidomic analysis was performed using liquid chromatography-tandem mass spectrometry. Using a measurement kit, we further confirmed whether lipid concentrations could be used as a potential CCA marker. RESULTS: Lipidomic analysis of bile sEVs in the two groups identified 209 significantly increased lipid species in the malignant group. When focusing on lipid class, phosphatidylcholine (PC) level was 4.98-fold higher in the malignant group than in the benign group (P = 0.037). The receiver operating characteristic (ROC) curve showed a sensitivity of 71.4%, a specificity of 100%, and an area under the curve (AUC) of 0.857 (95% confidence interval [CI]:0.643-1.000). Using a PC assay kit, the ROC curve showed a cutoff value of 16.1 µg/mL, a sensitivity of 71.4%, a specificity of 100%, and an AUC of 0.839 (95% CI: 0.620-1.000). CONCLUSION: PC level in sEVs from human bile is a potential diagnostic marker for CCA and can be assessed by a commercially available assay kit.

Anterior superior pancreaticoduodenal artery pseudoaneurysm after distal pancreatectomy with en bloc celiac axis resection successfully treated with balloon-assisted coil embolization.

Bleeding is a fatal complication after pancreatectomy. Although coil embolization is a widely accepted treatment option, ischemia of the remaining organs should be prevented. This study reports the successful treatment of intra-abdominal hemorrhage following distal pancreatectomy with en bloc celiac axis resection (DP-CAR) using balloon-assisted coil embolization (BACE). A 59-year-old man was diagnosed with locally advanced pancreatic cancer. The tumor involves the common hepatic artery, splenic artery, and celiac artery. After four cycles of treatment with gemcitabine/nab-paclitaxel, the soft-density masses, surrounding the artery, shrunk. DP-CAR and R0 resections were performed. A minor postoperative pancreatic fistula occurred. Six months postoperatively, the computed tomography showed delayed asymptomatic bleeding from an anterior superior pancreaticoduodenal artery (ASPDA) pseudoaneurysm located near the gastroduodenal artery confluence. BACE was performed by placing a microballoon catheter in the region of confluence of the ASPDA and posterior superior pancreaticoduodenal artery (PSPDA) to prevent coil migration. After inserting the microballoon catheter, coil embolization was performed in the ASPDA. Hepatic blood flow was maintained from the PSPDA. BACE is a useful technique to preserve blood flow to the remnant organs when performing coil embolization for bleeding following a distal pancreatectomy, especially following a DP-CAR.

Refractory postoperative Staphylococcus hominis bacteremia in a patient with an ACTH-producing pancreatic neuroendocrine neoplasm: a case report.

BACKGROUND: Staphylococcus hominis (S. hominis) is an opportunistic pathogen that is often highly resistant to antibiotics and is difficult to treat. In patients diagnosed with an adrenocorticotropic hormone (ACTH)-producing tumor that compromises the immune system due to hypercortisolemia, cancer treatment and infection control should be considered simultaneously. This report presents a case of refractory postoperative S. hominis bacteremia requiring the prolonged administration of several antibiotics in a patient with an ACTH-producing pancreatic neuroendocrine neoplasm (pNEN). CASE PRESENTATION: A 35-year-old man visited a neighboring hospital for a thorough examination after experiencing weight gain and lower limb weakness for several months. Enhanced computed tomography revealed a pancreatic tail tumor and bilateral adrenal enlargement. Elevated plasma ACTH and serum cortisol were noted. Biopsy under endoscopic ultrasonography revealed the tumor as an ACTH-producing pNEN. The patient was transferred to our hospital for further treatment. Pneumocystis pneumonia was noted and treated with sulfamethoxazole and adjunctive glucocorticoids. Hypercortisolism was controlled with metyrapone and trilostane. Somatostatin receptor scintigraphy and ethoxybenzyl magnetic resonance imaging detected other lesions in the pancreatic head. A total pancreatectomy was performed given that the lesions were found in both the pancreatic head and tail. Plasma ACTH and serum cortisol levels decreased immediately after the resection. Pathological examination revealed that the pancreatic tail tumor was NEN G2 and T3N1aM0 Stage IIB and the pancreatic head lesions were SSTR-positive hyperplasia of the islet of Langerhans cells. On postoperative day 11, catheter-associated bacteremia occurred. Initially, meropenem hydrate and vancomycin hydrochloride were administered empirically. S. hominis was identified and appeared sensitive to these antibiotics according to susceptibility testing. However, S. hominis was repeatedly positive in blood cultures for more than one month, despite treatment with several antibiotics. Eventually, with the combined use of three antibiotics (meropenem hydrate, vancomycin hydrochloride, and clindamycin phosphate) for more than 3 weeks, the S. hominis-associated bacteremia improved. He was discharged 79 days after surgery. CONCLUSIONS: Our patient with an ACTH-producing pNEN was immunocompromised and needed meticulous attention for infectious complications even after successful tumor removal. Specifically, S. hominis bacteremia in such patients demands intensive treatments, such as with combinational antibiotics.

Comparison of operative outcomes between monopolar and bipolar coagulation in hepatectomy: a propensity score-matched analysis in a single center.

BACKGROUND: Various hemostatic devices have been utilized to reduce blood loss during hepatectomy. Nonetheless, a comparison between monopolar and bipolar coagulation, particularly their usefulness or inferiority, has been poorly documented. The aim of this study is to reveal the characteristics of these hemostatic devices. METHODS: A total of 264 patients who underwent open hepatectomy at our institution from January 2009 to December 2018 were included. Monopolar and bipolar hemostatic devices were used in 160 (monopolar group) and 104 (bipolar group) cases, respectively. Operative outcomes and thermal damage to the resected specimens were compared between these groups using propensity score matching according to background factors. Multivariate logistic regression analysis was performed to identify predictive factors for postoperative complications. RESULTS: After propensity score matching, 73 patients per group were enrolled. The monopolar group had significantly lower total operative time (239 vs. 275 min; P = 0.013) and intraoperative blood loss (487 vs. 790 mL; P < 0.001). However, the incidence rates of ascites (27.4% vs. 8.2%; P = 0.002) and grade ≥ 3 intra-abdominal infection (12.3% vs. 2.7%; P = 0.028) were significantly higher in the monopolar group. Thermal damage to the resected specimens was significantly longer in the monopolar group (4.6 vs. 1.2 mm; P < 0.001). Use of monopolar hemostatic device was an independent risk factor for ascites (odds ratio, 5.626, 95% confidence interval 1.881-16.827; P = 0.002) and severe intra-abdominal infection (odds ratio, 5.905, 95% confidence interval 1.096-31.825; P = 0.039). CONCLUSIONS: Although monopolar devices have an excellent hemostatic ability, they might damage the remnant liver. The use of monopolar devices can be one of the factors that increase the frequency of complications.

A comprehensive strategy for perioperative care of pancreaticoduodenectomy according to the risk stratification by pancreatic fistula and delayed gastric emptying.

BACKGROUND/OBJECTIVE: Pancreaticoduodenectomy (PD) is highly invasive with unsatisfactory postoperative complication rates. Nutritional and fluid management after major surgery attracts much attention with regard to the reduction in severe postoperative complications. We retrospectively analyzed PD cases and proposed a novel strategy for perioperative fluid and nutritional therapy according to the risk stratification by pancreatic fistula (PF) and delayed gastric emptying (DGE). METHODS: Between 2003 and 2018, 140 patients underwent PD at our institute of which 134 patients were enrolled. We evaluated the clinicopathological factors affecting severe (≥10%) body weight loss (BWL), factors affecting the incidence of PF and intraabdominal complications (IAC), and factors related to DGE. RESULTS: Multivariate analysis indicated that male sex, severe PF, and DGE are significant risk factors for BWL ≥10%. PF and IAC were predominantly observed in male patients and those with non-pancreatic cancer. A fluid balance ≥6000 ml on postoperative day 2 was the sole risk factor for primary DGE. Secondary DGE significantly correlated with stomach preserving PD. Importantly, the average BWL was around 15% in grade B or C secondary DGE. CONCLUSION: Severe postoperative complications resulted in significant BWL. Enteral feeding is unnecessary in cases with a hard pancreas and dilated pancreatic duct if appropriate perioperative fluid management is performed. Secondary DGE followed by PF or IAC is unavoidable to some extent, especially in the case of soft pancreas with a fine pancreatic duct. In such cases, enteral feeding with tube ileostomy should be considered, and stomach preserving PD is likely to be harmful.

Fatal pancreatic fistula after laparoscopic distal pancreatectomy for intraductal papillary mucinous carcinoma with pancreaticobiliary maljunction and sphincterotomized papilla: a case report.

BACKGROUND: Pancreatic juice is constantly activated by contaminated bile in patients with pancreaticobiliary maljunction (PBM). Here, we report a case of laparoscopic distal pancreatectomy for a patient with PBM and sphincterotomized papilla, resulting in fatal pancreatic fistula. CASE PRESENTATION: A 79-year-old man was diagnosed with pancreatic intraductal papillary mucinous neoplasm and common bile duct stones. Endoscopic sphincterotomy was performed prior to surgery. The pancreatic duct was simultaneously visualized when the contrast agent was injected into the common bile duct. Sudden bleeding was observed from the abdominal drain on postoperative day (POD) 6. Emergent stent graft placement and coil embolization were performed for bleeding from the splenic artery. On POD 9, the drainage fluid changed to yellowish in color with bile contamination. For internal drainage of the digestive fluid, endoscopic retrograde biliary tube and pancreatic drainage tube were placed. On POD 24, second emergent coil embolization was performed for bleeding from the left gastric artery. On POD 25, open abdominal drainage was performed. On POD 32, third emergent coil embolization was performed for bleeding from the gastroduodenal artery. Subsequently, remnant pancreatic resection was performed. On POD 39, massive bleeding was again observed from the abdominal drain. Emergency arterial portography revealed bleeding in the right wall of the superior mesenteric vein. The patient died of hemorrhagic shock on the same day. CONCLUSIONS: The extreme risk of severe pancreatic fistula after distal pancreatectomy should be considered in patients with PBM and sphincterotomized papilla. In this extraordinary situation, surgeons should promptly decide whether to resect the remnant pancreas to prevent losing the patient.

Ephrin Receptor A4 Expression Enhances Migration, Invasion and Neurotropism in Pancreatic Ductal Adenocarcinoma Cells.

BACKGROUND/AIM: We sought to identify the mechanisms of perineural invasion in pancreatic ductal adenocarcinoma (PDAC). MATERIALS AND METHODS: We utilized in vitro cancer cell-nerve co-culture models comprising human PDAC cell lines (MIA Paca2 and PANC-1) and a dorsal root ganglion (DRG) isolated from neonatal mice. We compared gene expression profiles between cell lines with/without DRG conditioned medium (DRG-CM) using RNA-sequencing (RNA-seq). RESULTS: Migration, invasion, and neurotropism were significantly enhanced in MIA Paca2 but not in PANC-1 cells co-cultured with DRGs. Among 285 genes which showed significant differences in expression levels between cell lines in RNA-seq, we focused on Ephrin receptor A4 (EPHA4), which was upregulated in MIA Paca2 cells treated with DRG-CM. The abilities of migration, invasion, and neurotropism enhanced by DRG co-culture were abolished when EPHA4 was knocked down by siRNA in MIA Paca2 cells. CONCLUSION: EPHA4 can be a potential target gene to regulate perineural invasion in PDAC cells.

Risk Factors for Totally Implantable Central Venous Access Port-related Infection in Patients With Malignancy.

BACKGROUND: We sought to identify the risk factors of totally implantable central venous access port (TICVAP)-related infections in patients with malignant disease. PATIENTS AND METHODS: Overall, 324 consecutive patients who received a TICVAP at our institution were retrospectively analysed. We further analysed cases of TICVAP-related complications. The risk factors for TICVAP-related infection were investigated using Cox regression hazard models. RESULTS: With a median TICVAP duration of 268 days (range=1-1,859 days), TICVAP-related complications were observed in 36 cases and infectious complications in late phase were the most common, seen in 19 cases (9.26%). A multivariate analysis showed that patients with head and neck malignancy (p<0.001) and patients who received TICVAP insertion in the upper arm (p<0.001) were independently at a higher risk for TICVAP-related infections. CONCLUSION: Patients with head and neck malignancy or TICVAP insertion in the upper arm have potentially increased risk for late-phase TICVAP-related infections.

Aggressive Recurrent Pancreatic Cancer Producing Granulocyte Colony-Stimulating Factor.

Granulocyte colony-stimulating factor (G-CSF) is a glycoprotein which stimulates the proliferation, differentiation, and functional activation of myeloid hematopoietic cells. G-CSF-producing pancreatic cancer is rare and its prognosis is strikingly poor. A 69-year-old woman with well-to-moderately differentiated ductal adenocarcinoma (pT3N0M0, stage IIA) underwent distal pancreatectomy and splenectomy. Postoperative adjuvant chemotherapy with S-1 was administered for 6 months. Eleven months after surgery, periodic blood examination revealed remarkable leukocytosis (19,120/µL) without fever, which worsened 3 weeks later (36,160/µL). Furthermore, laboratory data showed elevation of the fibrin degradation product-D dimer and that the G-CSF level was high (406 pg/mL), as well as thrombopenia. Multiple liver and lung metastases were detected by contrast-enhanced computed tomography (CT). The patient was treated with gemcitabine plus nab-paclitaxel, and heparin, thrombomodulin alfa, and platelet transfusion were administered concurrently. Leukocytosis and thrombopenia were alleviated after 1 course of chemotherapy. However, remarkable leukocytosis (53,480/µL) recurred on day 1 of the third course of chemotherapy. Contrast-enhanced CT showed a significantly increased number of liver metastases and lung metastases. The patient chose not to receive second-line chemotherapy and died 1 month later at the affiliated hospital. Pancreatic cancer producing G-CSF shows very aggressive behavior. Leukocytosis without infection during routine observation should be considered as a warning of a rapidly growing recurrence.

Multimodal therapy with surgery and adjuvant nivolumab for late-onset multiple liver metastases of choroidal malignant melanoma: a case report.

BACKGROUND: Choroidal malignant melanoma is the most common primary malignant tumor of the eye in adults. Prognosis after recurrence of this disease has been dismal because of the absence of an effective therapy. However, resection of recurrent foci and a subsequent treatment with immune-checkpoint inhibitor may improve the prognosis after recurrence of this disease. This study presents a case of late-onset liver metastases of choroidal malignant melanoma, successfully treated with hepatectomy and postoperative adjuvant nivolumab. CASE PRESENTATION: A 53-year-old woman had undergone left ocular enucleation because of choroidal malignant melanoma 13 years prior to admission. She visited a nearby clinic with complaints of epigastric pain. She was referred to our hospital because a giant liver tumor was observed on abdominal ultrasonography. Enhanced computed tomography revealed multiple liver tumors in the right lobe, 49 mm in diameter with ring enhancement in subsegment (S) 5/6, and 14 and 8 mm without any enhancement in S7 and S5, respectively. On magnetic resonance imaging, the main tumor showed high intensity on T1-weighted with fat suppression, suggesting melanin deposition. Based on the diagnosis of multiple liver metastases of choroidal malignant melanoma, right hepatectomy and regional lymphadenectomy were performed. She was discharged without postoperative complications. Histological examination revealed that all tumors were metastatic malignant melanoma. She was treated with nivolumab postoperatively, and no recurrences were observed during 22 months of follow-up. CONCLUSIONS: Aggressive surgery plus adjuvant nivolumab appears to be a promising treatment for choroidal malignant melanoma with late-onset liver metastases.

[Solid serous cystic neoplasm of the pancreas showing a gradual tumor enlargement for over five years:a case report].

Serous cystic neoplasms (SCNs) of the pancreas are slow-growing benign tumors. They are mostly monitored without surgical management. Solid SCN is rare and differentiating it from hypervascular tumors of the pancreas using preoperative imaging may be difficult. A 69-year-old woman was referred to our department for surgical treatment of an enlarged pancreatic tail tumor with a size of 22mm based on the abdominal computed tomography (CT). At the age of 60, she underwent thyroidectomy for papillary thyroid carcinoma and mastectomy for breast cancer. Initially, consecutive annual CT examinations did not show signs of recurrence. However, after 9 years, a hypervascular pancreatic tumor was detected and assumed to be either a neuroendocrine tumor or metastasis. The patient underwent distal pancreatectomy, and the resected specimen was histopathologically diagnosed as solid SCN of the pancreas. Before being referred for pancreatic resection, this patient had been followed up with serial annual CT examinations for over 9 years after a previous malignant disease. Retrospectively, the abdominal CT scans showed that the pancreatic tumor already existed 5 years ago and had gradually increased in size thereafter. In this case report, we focused on the characteristics of solid SCN to address the difficulty in diagnosing this rare malignancy.