Pharmacists' Behavioral Changes after Attending a Multi-Prefectural Palliative Care Education Program.

Central to the pharmacist's role in palliative care is symptom management through direct participation in patient care and the provision of optimal pharmacotherapy to support patient outcomes. Consequently, palliative care requires extensive knowledge and action for patients with cancer. Therefore, this study aimed to evaluate how pharmacists' behavior changed after attending a palliative care educational program. We conducted a web-based questionnaire survey examining the behavior of pharmacists regarding palliative care before participating in the program, two months after participating in the program, and eight months after participating in the program to determine their behavior and changes over time. For all questions, scores were higher at two and eight months after attending the program than before attending the program (p < 0.05). In addition, no significant difference was observed between two and eight months after attending the program for any question (p = 0.504-1.000). The knowledge gained from the educational program was used to repeatedly intervene with patients with cancer in order to address the various symptoms they experienced and maintain their behavior. The proven effectiveness of this program serves as a stepping stone for nationwide rollout across Japan's 47 prefectures.

Conservative Treatment Using Platelet-Rich Plasma for Acute Anterior Cruciate Ligament Injuries in Highly Active Patients: A Retrospective Survey.

Background The recommended treatment for anterior cruciate ligament (ACL) injuries in active, sports-oriented patients is reconstructive surgery in order to regain stability and prevent secondary meniscal injuries. However, ACL reconstruction requires a long recovery period and poses issues such as decreased muscle strength due to tendon harvesting and postoperative osteoarthritis (OA) progression, thereby raising significant expectations for the advancement of conservative treatments. Recent studies have shown that platelet-rich plasma (PRP) therapy, which utilizes the tissue repair-promoting property of platelets, is effective for ACL injuries. Methods We administered PRP therapy within six weeks after ACL injury in patients who expressed the desire for an early return to sports through conservative care. After the treatment, patients wore a simple brace that limited deep flexion but placed no restrictions on weight bearing. Four months was the standard goal established for returning to pre-injury condition, and, depending on the target level, timing, and knee condition, we adjusted the additional PRP treatments and rehabilitation approach, gradually authorizing the patients' return to sport. We assessed the ligament repair status by magnetic resonance imaging (MRI) just before the full return to sports. A retrospective survey was conducted to evaluate the status of ligament repair and the condition of return-to-sport in patients with ACL injuries who underwent conservative treatment using PRP. Results The average patient age was 32.7 years and the average treatment was 2.8 PRP sessions. MRI evaluations confirmed that ligament continuity was regained in all cases. All the patients returned to their pre-injury level (Tegner Activity Scale 7.0) in an average of 139.5 days, but there was one instance of re-rupture following the return to sports. Conclusion All patients with ACL injury who underwent PRP therapy regained ligament continuity and returned to sport successfully with only one case of re-rupture.

Effectiveness of educational program on systematic and extensive palliative care in cancer patients for pharmacists.

BACKGROUND AND PURPOSE: Continuing education is essential for pharmacists to acquire latest knowledge. Our previously established educational program for pharmacists on the systematic and extensive palliative care of cancer patients was evaluated for its educational effectiveness in one urban prefecture. However, whether the same learning effect can be achieved when a program is expanded from one urban prefecture to multiple rural prefectures is unclear. In this study, we examined whether the continuing education program would be useful to pharmacists, even if the scale was expanded. EDUCATIONAL ACTIVITY AND SETTING: With the aim of correcting educational disparities in the region, pharmacists living in nine prefectures in the Kyushu area underwent a systematic and extensive palliative care educational program for six days (with 24 topics in total). They were administered a questionnaire before and after each topic to evaluate their level of understanding. FINDINGS: The level of understanding of the 24 topics in the program that palliative care pharmacists underwent, from "basic knowledge" to "clinical application," significantly improved (P < .01). SUMMARY: The educational program for pharmacists is useful even when implemented on a larger scale. We believe that our efforts are important for improving community-based care.

A long-term survival case with recurrent esophageal adenosquamous carcinoma.

We experienced an extremely rare case of recurrent esophageal adenosquamous carcinoma showing cutis, bone and adrenal gland metastases. Furthermore, the patient showed complete remission by chemotherapy and irradiation, with a long-term survival of over 8 years. A 46-year-old man with esophago-gastric junction cancer of clinical stage II was administered two cycles of neo-adjuvant chemotherapy with FP (5FU 800 mg/mm2 Cisplatin 80 mg/mm2 every 3 weeks), subsequently, underwent esophagectomy and mediastinal and celiac lymph node dissection. However, at 1 month after the surgery, he was admitted again due to a 1 cm cutaneous metastasis at the anterior chest wall and left side adrenal gland metastasis. Furthermore, magnetic resonance imaging showed bone metastasis at the second cervical vertebra. He was administered weekly docetaxel at 40 mg/body (3 times every 4 weeks) for 27 cycles. Irradiation therapy (liniac 36 Gy/16Fr) was performed for the vertebral metastasis. The cutaneous and adrenal metastases were diminished and complete remission persisted for over 8 years.

Evaluation of changes in pharmacist behaviors following a systematic education program on palliative care in cancer.

BACKGROUND AND PURPOSE: Attitudes, experience, and knowledge of healthcare professionals guide the care they provide and are particularly important factors affecting the quality of palliative care. Palliative care education for pharmacists is crucial for improving quality of care and effective participation on the palliative care team. EDUCATIONAL ACTIVITY AND SETTING: We previously developed and reported a systematic and multifaceted pharmacist education program for cancer-related palliative care. We compared 12 behavioral changes immediately (August 2017) and two years after (October 2019) participation in this systematic education program (SEP) to evaluate if participants were performing pharmaceutical management appropriately and to assure that behaviors had not deteriorated. FINDINGS: Of 88 participants in the SEP, 36 responded to the survey (response rate 40.9%). There was no significant difference in the behavioral change items of pharmacists immediately after participating in the SEP (2017) and two years later (2019) (4.47 vs. 4.58, P = .47). SUMMARY: We confirmed that behavioral changes developed by the SEP were maintained over a significant time. This indicates that knowledge was firmly established in the participants such that they could continue utilizing it long after participating in the SEP. Our study showed that participating in this SEP not only enabled participants to acquire knowledge regarding palliative medicine but also led to continued behavioral changes based on this knowledge.

Multi-regional sequencing reveals clonal and polyclonal seeding from primary tumor to metastases in advanced gastric cancer.

BACKGROUND: Tumor metastases to lymph nodes and distant organs are associated with worse prognosis in gastric cancer. However, little is known about the genetic profiles, subclonal architecture, and evolutional processes across primary tumors and metastases. METHODS: We analyzed the genetic alterations of 106 multiregional samples including primary tumors, lymph node metastases, and visceral metastases from 10 patients with advanced gastric cancer. Histologically different portions were obtained by laser-capture microdissection. We reconstructed the subclonal architectures and inferred the primary to lymph or visceral metastatic seeding patterns. RESULTS: The different histological portions in primary tumors had common mutations, suggesting common ancestral tumor origins transformed into distinct histological types. In almost all cases, TP53 mutations were identified as clonal mutations across primary tumors and metastases. Subclonal reconstruction and phylogenetic analysis showed primary tumors were classified into monoclonal or polyclonal tumors. All monoclonal primary tumors disseminated as metastases with the same tumor composition (100%, 26/26 samples). In contrast, polyclonal primary tumors mainly spread as metastases by way of polyclonal seeding (84%: 37/44 samples). CONCLUSIONS: Clonal mutations were maintained at both the primary and metastatic sites and genetic divergence of these was low. These findings shed light on the genetic basis of primary tumor dissemination and metastatic processes in advanced gastric cancer.

Rapidly declining trend of signet ring cell cancer of the stomach may parallel the infection rate of Helicobacter pylori.

BACKGROUND: Studies indicate that gastric cancer (GC) incidence has decreased, whereas signet ring cell carcinoma (SRC) incidence has increased. However, recent trends in GC incidence are unclear. We used our hospital cancer registry to evaluate the changes in the incidence of GC, SRC, and non-SRC (NSRC) over time in comparison to changes in the H. pylori infection rates over time. METHODS: We identified 2532 patients with GC enrolled in our registry between January 2007 and December 2018 and statistically analyzed SRC and NSRC incidence. The H. pylori infection rate in patients with SRC was determined by serum anti-H. pylori antibody testing, urea breath test, biopsy specimen culture, and immunohistochemical analysis (IHC) of gastric tissue. Additionally, genomic detection of H. pylori was performed in SRCs by extracting DNA from formalin-fixed paraffin-embedded gastric tissue and targeting 16S ribosomal RNA of H. pylori. RESULTS: Overall, 211 patients had SRC (8.3%). Compared with patients with NSRC, those with SRC were younger (P <  0.001) and more likely to be female (P <  0.001). Time series analysis using an autoregressive integrated moving average model revealed a significant decrease in SRC (P <  0.001) incidence; NSRC incidence showed no decline. There was no difference in H. pylori infection prevalence between the SRC and NSRC groups. IHC and genomic methods detected H. pylori in 30 of 37 (81.1%) SRCs. CONCLUSIONS: Reduction in H. pylori infection prevalence may be associated with the decrease in the incidence of SRC, which was higher than that of NSRC.

Deficiency of mismatch repair genes is less frequently observed in signet ring cell compared with non-signet ring cell gastric cancer.

Signet ring cell (SRC) gastric cancer at advanced stage has poor prognosis. While a recent study reported nearly one-third of SRC cases contain tumors with deficient mismatch repair (MMR) genes, other studies in SRC have been inconclusive. To re-analyze the results, we performed immunohistochemical staining of MLH1, MSH2, MSH6 and PMS2 proteins in 38 SRC gastric tumors compared with 109 non-SRC (NSRC) tumors from 94 patients. In contrast to the previous study, all SRC gastric tumors normally expressed MMR proteins, whereas 22 of 109 of NSRC (20%) showed deficient MMR proteins. To reinforce our results, we referred to the Cancer Genome Atlas (TCGA) genomic database and found that only 6 (6%) of 99 samples with diffuse gastric tumors showed deficient MMR, whereas 64 (21%) of 304 in intestinal gastric tumors showed deficient MMR. Our results as well as the TCGA database indicated that MMR genes are infrequently inactivated in SRC gastric cancer. These findings indicate that SRC patients may not be the best candidates for immuno-oncology therapy.

Biliary cancer developed after the reparative surgery for congenital choledochal cyst: a case report and review of the literature.

The incidence of bile duct cancer developed in the patients with congenital choledochal cysts (CC) with a history of reparative surgery is not well known. We experienced a case developed choleductal cancer 45 years after reparative surgery. She underwent reparative surgery with cyst excision and hepatic bile duct duodenal anastomosis at 1 year of age. She developed the symptoms of jaundice, anorexia, and dull pain in the right upper part of the abdomen at 47 years of age. The carcinoma arose from the dilated proximal bile duct anastomosed with the duodenum. Cholestasis and regurgitation of duodenal fluids seemed to have influenced the development of cancer in this patient. We additionally reviewed seven cohort studies concerning the incidence of biliary carcinoma after surgery for congenital choledocal cysts. The incidence of biliary cancer developed after surgery was 2.2 ± 2.5 (ranged 0-6.5)%. We also reviewed 33 Japanese case reports cited in Japan MEDLINE from 1986 to 2015. Regarding the CC types according to the Totani's classification, 12 were type I and 14 type IVa, 1 was type II and 6 were unknown type. The rate of coexistence of pancreaticobiliary maljunction (PBM) was 92%, (22/24; other 9 cases were not documented), and biliary cancer arose from the proximal stump of the reparative surgery in 68% (17/25) and from the distal stump in 32% (8/25) of cases. These findings suggested that the reflux of pancreatic juice due to PBM only partially explained the carcinogenesis of CCs. Intensive follow-up of such patients throughout their lives is necessary to avoid cancer death even after standard reparative surgery.

Pseudomyxoma peritonei due to low-grade appendiceal mucinous neoplasm with symptoms of inguinal hernia and uterine prolapse: a case report and review of the literature.

Pseudomyxoma peritonei (PMP) is an unusual condition in which massive amounts of mucinous ascites in conjunction with mucinous peritoneal and omental implants occur. We herein report a case of PMP due to low-grade appendiceal neoplasm (LAMN) and a literature review to clarify the clinical features of PMP. A 68-year-old female suffered from anorexia and abdominal distension and was referred to the emergency department of our hospital. Right-side inguinal hernia and uterine prolapse were revealed by a physical examination. Abdominal computed tomography at admission indicated massive ascites and a ruptured cystic mass in the lower-right abdomen. We diagnosed the patient with a ruptured appendiceal mucinous adenoma and PMP and scheduled a laparotomy. We performed an appendectomy containing the cystic mass, bilateral oophorectomy, and a biopsy for the peritoneum. We irrigated the abdominal cavity using 3000 ml of dextran solution. The macroscopic findings showed a ruptured cystic mass measuring 5 × 4 cm arising from the middle of the appendix. The bilateral ovaries and peritoneum were also covered with yellow mucin. The pathologic findings revealed the presence of low-grade atypical cells inside the capsule. However, no tumor cells were found on the surface of the ovary or peritoneum. A literature review revealed that the prognosis of PMP due to LAMN is relatively good, with a 5-year survival rate of 80%, and hernia is occasionally caused by PMP. According to this literature review, we knew this case might be a typical case. However, PMP is very rare; we need further follow-up data to select an optimal treatment for preventing the relapse of PMP.

Periaortitis induced by epirubicin and cyclophosphamide for a patient with advanced breast cancer.

Aortitis is an extremely rare condition, and it may mimic febrile neutropenia during cancer chemotherapy. A 55-year-old female diagnosed with T2N1M1 stage IV breast carcinoma received chemotherapy with EC (epirubicin 90 mg/m2 and cyclophosphamide 600 mg/m2 every 3 weeks). At the eleventh day after the first administration of EC, she developed a high-grade fever of 38 °C and stomatitis. We started the intravenous administration of antibiotics at hospitalization, because the laboratory data showed normal white blood cell values 3800/µl but a severe inflammatory reaction (CRP 25.13 mg/dl). The fever and high CRP value continued, and the WBC rose to 14,500/µl at 20th day. However, her condition was stable. On the 25th day after the administration of EC, she complained of back pain, so we performed computed tomography (CT) again and observed thickening of the rind surrounding the descending aorta and bilateral pleural effusion, indicating acute periaortitis. We performed examinations concerning vasculitis and connective tissue disease, but the values were all within normal ranges showing no relationship with other diseases. We stopped the administration of antibiotics on the 20th day, and while we did not administer corticosteroids, however, the fever was resolved and her WBC decreased. She was discharged on day 33, and the other chemotherapy was restarted with pertuzumab, trastuzumab and docetaxel. The patient has remained well without inflammatory reactions. CT at 90 days after EC therapy showed the resolution of the thickened rind of the descending aorta and no aneurysmic changes.

Report of a case with gallbladder carcinoma: P53 expression of the peritumor epithelium might predict biliary tract recurrence.

INTRODUCTION: The over-expression of P53 protein in gallbladder carcinoma is a biomarker correlating with a poor survival. However, the significance of P53 expression in peritumor tissues is unknown. We experienced a case of gallbladder carcinoma where the operative specimen showed over-expression of P53 on the peritumor epithelium, and early recurrence developed at the biliary tract. PRESENTATION OF CASE: A 74-year-old female patient was referred to our hospital due to wall thickening of the gallbladder on ultrasonography. Radiographic examinations revealed wall thickening at the fundus of gallbladder and no abnormalities of the biliary tract or surrounding lymph nodes. We performed open cholecystectomy and lymph node dissection without extrahepatic bile duct resection, as a frozen section of the surgical stump of the cystic duct was cancer-free. However, a pathological examination revealed over-expression of P53 protein in the epithelium of the peritumor to the cystic duct, which were diagnosed as normal on hematoxylin eosin staining. The patient developed bile duct metastases, two and half years after the operation. She underwent endoscopic stenting for the obstruction of bile duct with no additional therapy, and died 6 months later. DISCUSSION AND CONCLUSION: The immunohistochemical staining of the GB wall or surgical stump for a surgical specimen of GBC may be crucial to predict the bile duct recurrence.

Pseudo-Meigs' syndrome due to ovarian metastases from colon cancer: a case report and review of the literature.

We herein experienced a case with pseudo-Meigs' syndrome that developed both synchronous and metachronous metastases to the ovary from ascending colon cancer. A 57-year-old female visited a hospital for a 2-month history of abdominal distension and voiding difficulty. Massive pleural effusion on the right side and a small amount of left-sided pleural effusion were detected on CT. She underwent emergent laparotomy due to the severe symptom of abdominal distention. The tumor originated from the left ovary, and left-sided oophorectomy was performed.The histologic finding was moderately differentiated adenocarcinoma suggesting metastatic carcinoma from the colon. Left thoracic effusion disappeared at 3 days after the removal of the ovarian tumor. Subsequently, colon carcinoma of the cecum was detected by colonoscopy. The patient underwent second laparotomy of right colectomy and lymph node dissection. However, 6 months after the operation, pleural effusion on the right side re-developed again, and the serum levels of CEA and CA125 were elevated at 105 ng/ml and 125 U/ml, respectively. CT again revealed a large ovarian tumor. She subsequently underwent third laparotomy of right-sided oophorectomy and hysterectomy. Pleural effusion and ascites disappeared in a few days after the operation.The patient developed both synchronous and metachronous ovarian metastases and achieved a 7-year disease-free survival after the operation. The pathogenesis of pseudo-Meigs' syndrome should be distinguished from carcinomatous peritonitis and/or pleuritis of malignant disease.

Report of a case with a spontaneous mesenteric hematoma that ruptured into the small intestine.

INTRODUCTION: A spontaneous mesenteric hematoma is a rare condition. Furthermore, it is extremely rare that the mesenteric hematoma caused gastrointestinal bleeding with an unknown etiology. We experienced a case with a spontaneous mesenteric hematoma that ruptured into the jejunum. PRESENTATION OF CASE: A 75-year-old man was referred to our hospital because of anal bleeding and anemia. Abdominal computed tomography (CT) showed a low density mass measuring 3.0cm in diameter, including an enhanced spot. This finding suggested that a pseudo-aneurysm or mesenteric hematoma caused active bleeding into the jejunum. He underwent emergent laparotomy and partial resection of the jejunum and the mesentery including the tumor. A histological examination of the jejunum indicated no pathogenic findings causing active bleeding. And there were no findings suggesting the mesenteric aneurysm had developed. The patient had no history related to the development of a mesenteric hematoma, such as trauma, labor, surgery, or anticoagulant treatment. Therefore, we finally diagnosed that a spontaneous mesenteric hematoma had ruptured into the jejunum. DISCUSSION AND CONCLUSION: We reported extremely rare condition that the mesenteric hematoma was developed and ruptured into the jejunum without definitive etiology.

Life-threatening metastasis was suppressed by trastuzumab containing regimen in a patient with Her2-negative breast cancer.

A 49-year-old female was referred to our hospital with left breast cancer and subsequently underwent mastectomy and axillary dissection. The pathological findings showed invasive breast cancer with lymph node metastasis (2/22), nuclear grade 3, ER (6+) PgR (2+) for the Allred score, and Her2 (2+) in an immunohistochemistry. We determined the subtype of Her2-negative breast cancer according to the fluorescent in situ hybridization results, as follows: Her2/CEP17 ratio 1.1 < 2.0. The patient received the EC regimen followed by docetaxel, and toremifene was subsequently administered. One year after the operation, the CA15-3 level was elevated at 50 ng/ml, and CT revealed liver metastases. Disease progression was not suppressed by paclitaxel containing regimen and eribulin. Then, we subsequently sought to determine whether the metastatic lesion showed the Her2 expression. Although the Her2 expression in the axillary lymph node metastases showed heterogeneous staining, the results were judged as Her2 (1+) according to the ASCO/CAP guidelines. We decided to administer trastuzumab and docetaxel due to the patient's life-threatening status, after which the CA15-3 level decreased and the symptom of fatigue improved. A total of 9 cycles of trastuzumab and docetaxel were administered, followed by maintenance trastuzumab continued to the present time. Physicians should be aware of the statement in the ASCO/CAP guidelines that the clinical decision to ultimately consider Her2-targeted therapy should be individualized according to the patient's status.

A case of advanced rectal cancer with rectovesical and ileal fistulae that developed hyperammonemic encephalopathy.

Hyperammonemic encephalopathy is rarely caused by a urinary diversion. We herein experienced a case of rectal carcinoma with rectovesical and ileal fistulae that developed hyperammonemic encephalopathy. A 72-year-old man suffered from a fever, diarrhea, pneumaturia, and fecaluria beginning in April 2013 and was referred to our hospital in May 2013. He developed a loss of consciousness and whole body cramping on the first hospital day. The laboratory data indicated an inflammatory reaction and hyperammonemia with a highly elevated serum ammonia (NH3) level of 703 µg/dl. The patient was diagnosed to have rectal carcinoma with rectovesical and ileal fistulae according to computed tomography (CT) and a water-soluble contrast enema. We administered a solution of branched chain amino acids (BCAA) and antibiotics. Furthermore, we repeatedly irrigated bladder through the urethral catheter. The patient's symptoms recovered, and the serum ammonia levels on the second and third hospital day were decreased to 210 and 135 µg/dl, respectively. However, the symptoms of infection and confusion were suspected to repeat; we elected to perform surgical treatment. An ileal disconnection with ileocecal bypass and sigmoidostomy were effective for preventing hyperammonemic encephalopathy.

Lung adenocarcinoma with clear cell features producing carbohydrate antigen 19-9.

A 76-year-old man underwent surgery for lung cancer. Histopathologically, most of the resected tumor was composed of polygonal cells with foamy cytoplasm, and the cells were arranged predominantly in acinar patterns. In this case, although the carbohydrate antigen 19-9 level was high before surgery, it normalized after resection. The tumor was considered a carbohydrate antigen 19-9-producing tumor, which was further supported by the results of immunohistochemical analysis. Adenocarcinoma with clear cell features, producing carbohydrate antigen 19-9, is an exceedingly rare entity.

Stratifying the risk of lymph node metastasis in undifferentiated-type early gastric cancer.

AIM: To study how lymph node metastasis (LNM) risk is stratified in undifferentiated-type early gastric cancer (undiff-EGC) dependent on combinations of risk factors. METHODS: Five hundred and sixty-seven cases with undiff-EGC undergoing gastrectomy with lymphadenectomy were examined retrospectively. Using clinicopathological factors of patient age, location, size, an endoscopic macroscopic tumor form, ulceration, depth, histology, lymphatic involvement (LI) and venous involvement (VI), LNM risk was examined and stratified by conventional statistical analysis and data-mining analysis. RESULTS: LNM was positive in 44 of 567 cases (7.8%). Univariate analysis revealed > 2 cm, protrusion, submucosal (sm), mixed type, LI and VI as significant prognostic factors and > 2 cm and LI-positive were independent factors by multivariate analysis. In preoperatively evaluable factors excluding LVI, sm and > 2 cm were independent factors. According to the depth and size, cases were categorized into the low-risk group [m and ≤ 2 cm, 0% (LNM incidence)], the moderate-risk group (m and > 2 cm, 5.6%; and sm and ≤ 2 cm, 6.0%), and the high-risk group (sm and > 2 cm, 19.3%). On the other hand, LNM occurred in 1.4% in all LI-negative cases, greatly lower than 28.2% in all LI-positive cases, and LNM incidence was low in LI-negative cases even in the moderate- and high-risk groups. CONCLUSION: LNM-related factors in undiff-EGC were depth and size preoperatively while those were LI and size postoperatively. Among these factors, LI was the most significantly correlated factor.

Report of a case with T1a gallbladder poorly differentiated adenocarcinoma, solid type, which developed into lymph node metastases.

We experienced a case with gallbladder carcinoma growing limited to the mucosa (T1a), which developed massive lymphatic vessel spread and lymph node metastases.A 72-year-old man was referred to our hospital for the swelling of his gallbladder during a routine ultrasound sonography checkup. We diagnosed the patient with gallbladder carcinoma with lymph node metastasis according to the radiographic findings and performed the open cholecystectomy and lymph node dissection. A histological examination showed poorly differentiated adenocarcinoma, solid type, and the tumor was limited to the mucosa. The number of lymphatic vessels was increased in the tumor and peritumor areas, and cancer cells were observed in the lymphatic vessels, which were detected via D2-40 immunohistochemistry. A careful histological examination and follow-up is required for T1a gallbladder carcinoma.

Gastrointestinal stromal tumor arising in an ileal duplication: report of a case.

This report presents the extremely rare case of an adult patient who presented with peritonitis caused by the perforation of an ileal duplication, associated with a gastrointestinal stromal tumor (GIST) arising within the duplication. A 70-year-old female was admitted to the hospital with lower abdominal pain. Abdominal computed tomography showed free air in the peritoneal cavity. An emergency laparotomy was performed, presuming diffuse peritonitis caused by a perforation of the gastrointestinal tract. The surgical findings showed that the peritonitis was caused by the perforation of an ileal duplication, 90 cm proximal to the ileocecal valve, with an extrinsic tumor protruding from the duplication. A segmental resection of the ileum-including the tumor and ileal duplication-was performed. Histopathology showed that the tumor was composed of spindle-shaped and epithelioid cells. The tumor was immunohistochemically positive for KIT, with a deletion mutation spanning the intron 10-exon 11 boundary. Accordingly, a diagnosis was made of a GIST arising within a duplication of the ileum. Duplications of the alimentary tract are encountered only occasionally in adults. Although quite rare, malignant change should therefore be considered as a possible complication when a solid portion is observed within a duplication of the alimentary tract.