Systemic Inflammatory Response Following Preoperative Chemoradiotherapy Can Affect Oncologic Outcomes in MSI-H/dMMR Rectal Cancer / 전남의대학술지

Systemic inflammatory response (SIR) is a crucial determinant of disease progression and survival in patients with colorectal cancer. This study investigated the prognostic relevance of changes in the platelet count on survival and the predictive value of changes in the platelet-to-lymphocyte ratio (PLR) and neutrophil-to-lymphocyte ratio (NLR) on the pathological tumor response to preoperative chemoradiotherapy (CRT) in patients with microsatellite instability-high (MSI-H) rectal cancer. From 2011 to 2022, data of 46 consecutive patients with MSI-H rectal cancer who were treated with preoperative CRT followed by curative surgery at Kyungpook National University Chilgok Hospital (Daegu, South Korea) were retrospectively analyzed. A 235 cut-off value was used to define whether PLR was high or low. Any change in the PLR or NLR was calculated on the basis of subtracting the pre-CRT PLR or NLR from the post-CRT values. Both pre-CRT and post-CRT values of the NLR and PLR were not significantly associated with clinical outcomes. Simple logistic regression analysis showed that a change in the PLR following CRT was not significantly associated with survival outcomes; however, patients who maintained a high change in the PLR following CRT showed significantly better pathologic T-stage. No statistically significant association was noted between changes in the platelet count and clinical outcomes of patients. The results suggested that changes in the PLR following CRT are associated with pathologic T-stage of the group. However, the SIR markers showed no prognostic values on the survival outcomes of the patients with MSI-H/mismatch repair-deficient (dMMR) locally advanced rectal cancer (LARC).

Laparoscopic right hemicolectomy with aortocaval lymphadenectomy, and pelvic peritoneum partial resection for ascending colon cancer

The aim of this video is to present the procedural details of laparoscopic right hemicolectomy with aortocaval (infrarenal aortic bifurcation) lymphadenectomy, partial resection of the pelvic peritoneum (peritoneal carcinomatosis index, 3), and hyperthermic intraperitoneal chemotherapy in a patient who received neoadjuvant chemotherapy for stage IVc colorectal cancer. The total operation time was 290 minutes, and the patient was discharged on a postoperative day 13 without any complications. No postoperative complications occurred until postoperative day 60. The pathological stage of the tumor was determined to be T3N2bM1c. The pelvic peritoneal nodule was pathologically confirmed as a metastatic lesion. Among the 12 harvested aortocaval lymph nodes, 6 were metastatic lymph nodes. The minimally invasive approach was safe and feasible in this highly selected patient with colon cancer, aortocaval lymph nodes, and peritoneal metastases.

A Standardized Pathology Report for Gastric Cancer: 2nd Edition

The first edition of ‘A Standardized Pathology Report for Gastric Cancer’ was initiated by the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists and published 17 years ago. Since then, significant advances have been made in the pathologic diagnosis, molecular genetics, and management of gastric cancer (GC). To reflect those changes, a committee for publishing a second edition of the report was formed within the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists. This second edition consists of two parts: standard data elements and conditional data elements.The standard data elements contain the basic pathologic findings and items necessary to predict the prognosis of GC patients, and they are adequate for routine surgical pathology service. Other diagnostic and prognostic factors relevant to adjuvant therapy, including molecular biomarkers, are classified as conditional data elements to allow each pathologist to selectively choose items appropriate to the environment in their institution. We trust that the standardized pathology report will be helpful for GC diagnosis and facilitate large-scale multidisciplinary collaborative studies.

A standardized pathology report for gastric cancer: 2nd edition

The first edition of ‘A Standardized Pathology Report for Gastric Cancer’ was initiated by the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists and published 17 years ago. Since then, significant advances have been made in the pathologic diagnosis, molecular genetics, and management of gastric cancer (GC). To reflect those changes, a committee for publishing a second edition of the report was formed within the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists. This second edition consists of two parts: standard data elements and conditional data elements. The standard data elements contain the basic pathologic findings and items necessary to predict the prognosis of GC patients, and they are adequate for routine surgical pathology service. Other diagnostic and prognostic factors relevant to adjuvant therapy, including molecular biomarkers, are classified as conditional data elements to allow each pathologist to selectively choose items appropriate to the environment in their institution. We trust that the standardized pathology report will be helpful for GC diagnosis and facilitate large-scale multidisciplinary collaborative studies.

Standardized Pathology Report for Colorectal Cancer, 2nd Edition

The first edition of the ‘Standardized Pathology Report for Colorectal Cancer,’ which was developed by the Gastrointestinal Pathology Study Group (GIP) of the Korean Society of Pathologists, was published 13 years ago. Meanwhile, there have been many changes in the pathologic diagnosis of colorectal cancer (CRC), pathologic findings included in the pathology report, and immunohistochemical and molecular pathology required for the diagnosis and treatment of colorectal cancer. In order to reflect these changes, we (GIP) decided to make the second edition of the report. The purpose of this standardized pathology report is to provide a practical protocol for Korean pathologists, which could help diagnose and treat CRC patients. This report consists of “standard data elements” and “conditional data elements.” Basic pathologic findings and parts necessary for prognostication of CRC patients are classified as “standard data elements,” while other prognostic factors and factors related to adjuvant therapy are classified as “conditional data elements” so that each institution could select the contents according to the characteristics of the institution. The Korean version is also provided separately so that Korean pathologists can easily understand and use this report. We hope that this report will be helpful in the daily practice of CRC diagnosis.

Tumor immune response and immunotherapy in gastric cancer

Remarkable developments in immuno-oncology have changed the landscape of gastric cancer (GC) treatment. Because immunotherapy intervenes with tumor immune response rather than directly targeting tumor cells, it is important to develop a greater understanding of tumor immunity. This review paper summarizes the tumor immune reaction and immune escape mechanisms while focusing on the role of T cells and their co-inhibitory signals, such as the immune checkpoint molecules programmed death-1 and programmed deathligand 1 (PD-L1). This paper also describes past clinical trials of immunotherapy for patients with GC and details their clinical implications. Strong predictive markers are essential to improve response to immunotherapy. Microsatellite instability, Epstein-Barr virus, PD-L1 expression, and tumor mutational burden are now regarded as potent predictive markers for immunotherapy in patients with GC. Novel immunotherapy and combination therapy targeting new immune checkpoint molecules such as lymphocyte-activation gene 3, T cell immunoglobulin, and mucin domain containing-3, and indoleamine 2,3-dioxygenase have been suggested, and trials are ongoing to evaluate their safety and efficacy. Immunotherapy is an important treatment option for patients with GC and has great potential for improving patient outcome, and further research in immuno-oncology should be carried out.

Uniform and bright light emission from a 3D organic light-emitting device fabricated on a bi-convex lens by a vortex-flow-assisted solution-coating method.

We herein present the results of a study on the novel fabrication process of uniform and homogeneous semiconducting polymer layers, in this case hole-injecting and fluorescent light-emitting layers that were produced by a simple solution-coating process for 3D conformal organic light-emitting diodes (3D OLEDs) on curvilinear surfaces. The solution-coating process used was a newly developed method of vortex-flow-assisted solution-coating with the support of spinning of the coating solution. It is shown that the vortex-flow-assisted spin-coating process can produce high-quality thin films at nanoscale thicknesses by controlling the liquid surface of the coating solutions, which can easily be adjusted by changing the spinning speed, even on complex curvilinear surfaces, i.e., a quasi-omnidirectional coating. This excellent film-forming ability without any serious film defects is mainly due to the reduction of line tension among the solution, air, and the substrate at the contact line due to vortex flows of the coating solution on the substrate during the vortex-spin-coating process. As a proof of concept, we present vortex-spin-coated 3D OLEDs fabricated on bi-convex lens substrates which exhibit excellent device performance with high brightness and current efficiency levels comparable to those of a conventional spin-coated 2D planar OLED on a flat substrate. It is also shown that the EL emission from the 3D OLED on the bi-convex lens substrate exhibits a diffusive Lambertian radiation pattern. The results here demonstrate that the vortex-flow-assisted spin-coating process is a promising approach for producing efficient and reliable next-generation OLEDs for 3D conformal opto-electronics.

Uniform two-dimensional crystals of polystyrene nanospheres fabricated by a surfactant-assisted spin-coating method with polyoxyethylene tridecyl ether.

Spin-coated self-assemblies of colloidal particles have been developed recently as an attractive close-packed monolayer of the particles for a variety of applications, but they are limited by the small area of their monolayers, especially given their low uniformity and monolayer coverage on large-area substrates. We report several noteworthy characteristics of a close-packed monolayer of polystyrene nanospheres (PS NSs) fabricated using a simple and inexpensive spin-coating method with a PS NS suspension mixed using the nonionic surfactant polyoxyethylene (12) tridecyl ether (PEO-TDE). In our study, we show that the PEO-TDE surfactant offers excellent wettability, surface tension, and a slow solvent evaporation rate of the PS NS suspension, similar to the conventional surfactant Triton X-100. We demonstrate that the relatively high monolayer coverage with reduced defects is produced when introducing the PEO-TDE surfactant. Specifically, monolayer coverage of more than 95% on a Si substrate was achieved, which is much better than that with the typical Triton X-100, and is one of the highest coverage rates realized by a spin-coating method. This excellent uniformity of the PS NS monolayer with high monolayer coverage is mainly attributed to the relatively low viscosity of the PS NS suspension, even at high concentrations of PEO-TDE. Moreover, the PEO-TDE surfactant provides highly uniform monolayers on a large-scale glass substrate even for large-sized PS NSs. We also highlight the fact that the PEO-TDE surfactant has another advantage in that the spin-coating process of the PS NS suspension can be done under common ambient laboratory conditions, unlike those required for the highly toxic Triton X-100. We therefore conclude that PEO-TDE can be a useful surfactant during the fabrication of close-packed monolayers for various applications owing to its simple and straightforward control of PS NSs, its uniform and high surface coverage, and due to the safety of the fabrication process.

High brightness and efficiency of polymer-blend based light-emitting layers without the assistance of the charge-trapping effect.

Polymeric light-emitting materials have been developed recently as an attractive solution-processable alternative to conventional vacuum-deposited small molecules in organic/polymeric light-emitting diodes, but they are still limited in terms of their performance, especially with low luminance and efficiency. We report on some noteworthy characteristics of a new type of single emitting layer (EML), composed of a blend of a host blue-emitting polyspirobifluorene-based copolymer and a guest yellow-emitting poly(p-phenylene vinylene) derivative copolymer. These host and guest polymers have nearly identical highest occupied molecular orbital levels of about 5.2 eV, and lowest unoccupied molecular orbital levels of about 2.4 eV and 2.9 eV, respectively, minimizing the prevailing charge-trapping properties of their blend. Even in the absence of the charge-trapping effect, it is shown that very bright green electroluminescent (EL) emission with a maximum luminance of ~142,000 cd/m2 can be realized for the blended host:guest EML at a moderate concentration (~5 wt%) of the guest polymer. Current efficiency is also observed to be up to ~14 cd/A, which is much higher than those (3.6~5.1 cd/A) of reference devices with pure host or pure guest polymeric EMLs. Moreover, there is a small change in green color emission, with CIE coordinates of (0.35, 0.60) even at high luminance, showing good color stability of the EL emission from the blended EML. These significant improvements in device performance are mainly attributed to efficient Förster resonance energy transfer between the host and guest polymers in the blended EML. Together with its simple structure and easy processability, the high brightness and efficiency of our blended polymeric EML provides a new platform for the development of solution-processable light-emitting devices and/or advanced emissive display devices.

Full-surface emission of graphene-based vertical-type organic light-emitting transistors with high on/off contrast ratios and enhanced efficiencies.

Surface-emitting organic light-emitting transistors (OLETs) could well be a core element in the next generation of active-matrix (AM) displays. We report some of the key characteristics of graphene-based vertical-type organic light-emitting transistors (Gr-VOLETs) composed of a single-layer graphene source and an emissive channel layer. It is shown that FeCl3 doping of the graphene source results in a significant improvement in the device performance of Gr-VOLETs. Using the FeCl3-doped graphene source, it is demonstrated that the full-surface electroluminescent emission of the Gr-VOLET can be effectively modulated by gate voltages with high luminance on/off ratios (~104). Current efficiencies are also observed to be much higher than those of control organic light-emitting diodes (OLEDs), even at high luminance levels exceeding 500 cd/m2. Moreover, we propose an operating mechanism to explain the improvements in the device performance i.e., the effective gate-bias-induced modulation of the hole tunnelling injection at the doped graphene source electrode. Despite its inherently simple structure, our study highlights the significant improvement in the device performance of OLETs offered by the FeCl3-doped graphene source electrode.

Rectal Invasion by Prostatic Adenocarcinoma That Was Initially Diagnosed in a Rectal Polyp on Colonoscopy

Despite anatomical proximity, prostatic adenocarcinoma with rectal invasion is extremely rare. We present a case of rectal invasion by prostatic adenocarcinoma that was initially diagnosed from a rectal polyp biopsied on colonoscopy in a 69-year-old Korean man. He presented with dull anal pain and voiding discomfort for several days. Computed tomography revealed either prostatic adenocarcinoma with rectal invasion or rectal adenocarcinoma with prostatic invasion. His tumor marker profile showed normal prostate specific antigen (PSA) level and significantly elevated carcinoembryonic antigen level. Colonoscopy was performed, and a specimen was obtained from a round, 1.5 cm, sessile polyp that was 1.5 cm above the anal verge. Microscopically, glandular tumor structures infiltrated into the rectal mucosa and submucosa. Immunohistochemically, the tumor cells showed alpha-methylacyl-CoA-racemase positivity, PSA positivity, and caudal-related homeobox 2 negativity. The final diagnosis of the rectal polyp was consistent with prostatic adenocarcinoma. Here, we present a rare case that could have been misdiagnosed as rectal adenocarcinoma.

Pheochromocytoma with Hypertensive Crisis Caused by Endoscopic Ultrasound-guided Tissue Sampling / 대한췌담도학회지

Although pheochromocytoma usually presents as a solid tumor, it can also present as a cystic lesion in the adrenal glands. Cystic lesions in the adrenal glands, along with hypertension, need attention to exclude pheochromocytoma. If ignored, they may lead to a hypertensive crisis with multi-organ failure. Proper preoperative preparation is important to prevent a hypertensive crisis during and after surgery. We report a case of pheochromocytoma with cystic degeneration that presented as a hypertensive crisis caused by endoscopic ultrasound-guided tissue sampling.

What are the most important prognostic factors in patients with residual rectal cancer after preoperative chemoradiotherapy? / 영남의대학술지

BACKGROUND: We aimed to establish robust histoprognostic predictors on residual rectal cancer after preoperative chemoradiotherapy (CRT).METHODS: Analyzing known histoprognostic factors in 146 patients with residual disease allows associations with patient outcome to be evaluated.RESULTS: The median follow-up time was 77.8 months, during which 59 patients (40.4%) experienced recurrence and 41 (28.1%) died of rectal cancer. On univariate analysis, residual tumor size, ypT category, ypN category, ypTNM stage, downstage, tumor regression grade, lymphatic invasion, perineural invasion, venous invasion, and circumferential resection margin (CRM) were significantly associated with recurrence free survival (RFS) or/and cancer-specific survival (CSS) (all p<0.005). On multivariate analysis, higher ypTNM stage and CRM positivity were identified as independent prognostic factors for RFS (ypTNM stage, p=0.024; CRM positivity, p<0.001) and CSS (p=0.022, p=0.017, respectively). Furthermore, CRM positivity was an independent predictor of reduced RFS and CSS, irrespective of subgrouping according to downstage (non-downstage, p<0.001 and p<0.001; downstage, p=0.002 and p=0.002) or lymph node metastasis (non-metastasis, p<0.001 and p=0.001; metastasis, p<0.001 and p<0.001).CONCLUSION: CRM status may be as powerful as ypTNM stage as a prognostic indicator for patient outcome in patients with residual rectal cancer after preoperative CRT.

Comparison of the Diagnostic Performances of Same-session Endoscopic Ultrasound- and Endoscopic Retrograde Cholangiopancreatography-guided Tissue Sampling for Suspected Biliary Strictures at Different Primary Tumor Sites / 대한소화기학회지

BACKGROUND/AIMS: Determining the cause of suspected biliary stricture is often challenging in clinical practice. We aimed to compare the diagnostic yields of endoscopic ultrasound-guided tissue sampling (EUS-TS) and endoscopic retrograde cholangiopancreatography-guided tissue sampling (ERCP-TS) in patients with suspected biliary stricture at different primary lesions. METHODS: We enrolled patients who underwent same-session EUS- and ERCP-TS for the evaluation of suspected biliary stricture. Forceps biopsy and/or brush cytology of intraductal lesions and fine-needle aspiration for solid mass lesions were performed during ERCP and EUS, respectively. RESULTS: One hundred and twenty-five patients treated at our institution between January 2011 and September 2016, were initially considered for the study. However, 32 patients were excluded due to loss of follow-up (n=8) and ERCP-TS on the pancreatic duct (n=20) or periampullary lesions (n=4). Of the 93 patients included, 86 had a malignant tumor including cholangiocarcinoma (n=39), pancreatic cancer (n=37), and other malignancies (n=10). Seven patients had benign lesions. EUS-TS had higher rate of overall diagnostic accuracy than ERCP-TS (82.8% vs. 60.2%, p=0.001), and this was especially true for patients with a pancreatic lesion (84.4% vs. 51.1%, p=0.003). CONCLUSIONS: EUS-TS was found to be superior to ERCP-TS for evaluating suspected biliary strictures, especially those caused by pancreatic lesions.

What are the most important prognostic factors in patients with residual rectal cancer after preoperative chemoradiotherapy? / 영남의대학술지

BACKGROUND@#We aimed to establish robust histoprognostic predictors on residual rectal cancer after preoperative chemoradiotherapy (CRT).@*METHODS@#Analyzing known histoprognostic factors in 146 patients with residual disease allows associations with patient outcome to be evaluated.@*RESULTS@#The median follow-up time was 77.8 months, during which 59 patients (40.4%) experienced recurrence and 41 (28.1%) died of rectal cancer. On univariate analysis, residual tumor size, ypT category, ypN category, ypTNM stage, downstage, tumor regression grade, lymphatic invasion, perineural invasion, venous invasion, and circumferential resection margin (CRM) were significantly associated with recurrence free survival (RFS) or/and cancer-specific survival (CSS) (all p<0.005). On multivariate analysis, higher ypTNM stage and CRM positivity were identified as independent prognostic factors for RFS (ypTNM stage, p=0.024; CRM positivity, p<0.001) and CSS (p=0.022, p=0.017, respectively). Furthermore, CRM positivity was an independent predictor of reduced RFS and CSS, irrespective of subgrouping according to downstage (non-downstage, p<0.001 and p<0.001; downstage, p=0.002 and p=0.002) or lymph node metastasis (non-metastasis, p<0.001 and p=0.001; metastasis, p<0.001 and p<0.001).@*CONCLUSION@#CRM status may be as powerful as ypTNM stage as a prognostic indicator for patient outcome in patients with residual rectal cancer after preoperative CRT.

Lead, Mercury, and Cadmium Exposure in the Korean General Population

BACKGROUND: Lead (Pb), mercury (Hg), and cadmium (Cd) are well-known environmental pollutants. They are unnecessary in the biological processes of humans. This study was performed to estimate the representative background exposure levels to the metals by measuring concentrations in whole blood of the Korean general population. METHODS: This population-based cross-sectional study included 4,000 subjects (1,886 males and 2,114 females) 0–83 years of age in 2010 and 2011. Adult subjects (≥ 19 years of age) were collected by sex- and age-stratified probability method, and preschool- and school-aged subjects were recruited by a cluster sampling method. Written consent was provided prior to blood sampling. Pb and Cd blood concentrations were determined by a flameless atomic absorption spectrophotometry, and blood Hg was analyzed by a direct Hg analyzer. RESULTS: The geometric mean, median and 95th percentile of blood Pb was 1.82 µg/dL, 1.83 µg/dL, and 3.78 µg/dL, respectively. The respective values were 2.92 µg/L, 2.87 µg/L, 9.12 µg/L for Hg, and 0.56 µg/L, 0.59 µg/L, 2.20 µg/L for Cd. Blood Pb and Hg were higher in males than in females, but no sex difference was observed, respectively, in subjects 0–4 years of age for Pb and in subjects less than 20 years for Hg. However, blood Cd was higher in females than in males and no sex difference was observed in subjects < 30 years of age. CONCLUSION: This study provides representative data of human exposure to Pb, Hg, and Cd covering whole age groups of the general population in Korea.

Ligand-Independent Epidermal Growth Factor Receptor Overexpression Correlates with Poor Prognosis in Colorectal Cancer / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Molecular treatments targeting epidermal growth factor receptors (EGFRs) are important strategies for advanced colorectal cancer (CRC). However, clinicopathologic implications of EGFRs and EGFR ligand signaling have not been fully evaluated. We evaluated the expression of EGFR ligands and correlation with their receptors, clinicopathologic factors, and patients’ survival with CRC. MATERIALS AND METHODS: The expression of EGFR ligands, including heparin binding epidermal growth factor-like growth factor (HBEGF), transforming growth factor (TGF), betacellulin, and epidermal growth factor (EGF), were evaluated in 331 consecutive CRC samples using mRNA in situ hybridization (ISH). We also evaluated the expression status of EGFR, human epidermal growth factor receptor 2 (HER2), HER3, and HER4 using immunohistochemistry and/or silver ISH. RESULTS: Unlike low incidences of TGF (38.1%), betacellulin (7.9%), and EGF (2.1%), HBEGF expression was noted in 62.2% of CRC samples. However, the expression of each EGFR ligand did not reveal significant correlations with survival. The combined analyses of EGFR ligands and EGFR expression indicated that the ligands–/EGFR+ group showed a significant association with the worst disease-free survival (DFS; p=0.018) and overall survival (OS; p=0.005). It was also an independent, unfavorable prognostic factor for DFS (p=0.026) and OS (p=0.007). Additionally, HER4 nuclear expression, regardless of ligand expression, was an independent, favorable prognostic factor for DFS (p=0.034) and OS (p=0.049), by multivariate analysis. CONCLUSION: Ligand-independent EGFR overexpression was suggested to have a significant prognostic impact; thus, the expression status of EGFR ligands, in addition to EGFR, might be necessary for predicting patients' outcome in CRC.

Two Cases of Endoscopic Papillectomy for Neuroendocrine Tumor Arising from Minor Papilla / 대한췌담도학회지

Most of neuroendocrine tumors are usually found in the gastrointestinal tract. Recently, the incidence of gastrointestinal neuroendocrine tumors seems to have increased. However, only a few cases of neuroendocrine tumor arising from the minor duodenal papilla have been reported. Currently, several options are available to treat the tumors of the minor duodenal papilla. Endoscopic papillectomy is increasingly performed as a minimally invasive alternative treatment to conventional surgical resection. We present two cases of neuroendocrine tumor arising from minor duodenal papilla, which were successfully resected by endoscopic papillectomy. Although surgical resection is considered to be a standard treatment for gastrointestinal neuroendocrine tumors, our experience suggests that endoscopic papillectomy can be a minimally invasive alternative treatment for neuroendocrine tumors arising from the minor duodenal papilla.

Two Cases of Endoscopic Papillectomy for Neuroendocrine Tumor Arising from Minor Papilla / 대한췌담도학회지

Most of neuroendocrine tumors are usually found in the gastrointestinal tract. Recently, the incidence of gastrointestinal neuroendocrine tumors seems to have increased. However, only a few cases of neuroendocrine tumor arising from the minor duodenal papilla have been reported. Currently, several options are available to treat the tumors of the minor duodenal papilla. Endoscopic papillectomy is increasingly performed as a minimally invasive alternative treatment to conventional surgical resection. We present two cases of neuroendocrine tumor arising from minor duodenal papilla, which were successfully resected by endoscopic papillectomy. Although surgical resection is considered to be a standard treatment for gastrointestinal neuroendocrine tumors, our experience suggests that endoscopic papillectomy can be a minimally invasive alternative treatment for neuroendocrine tumors arising from the minor duodenal papilla.

Actinomycosis Involving Chronic Pancreatitis: A Case Report with Literature Review / 대한소화기학회지

Actinomycosis is a slowly progressive, chronic infectious disease. It is caused by the genus Actinomyces, which are gram-positive anaerobic bacteria. It presents as a mass-like lesion, composed of bacterial nidus and characteristic granulomatous inflammatory fibrosis. As such, it has frequently been mistaken for a malignancy. Surgical resection is a common procedure in these patients prior to a definite diagnosis. Although actinomycosis can occur in a variety of regions, including oral-cervicofacial, thoracic, and abdominopelvic cavities, the involvement of the pancreas is very rare. We report a case of a 44-year-old male with a symptomatic actinomycosis caused by a mass in the tail of the pancreas. The diagnosis was made using an endoscopic ultrasound-guided fine needle aspiration biopsy without surgical resection. After the treatment with antibiotics, the pancreatic mass was confirmed to be resolved on the follow-up computed tomography.