Long-Term Complete Response to Trastuzumab Deruxtecan in a Case of Unresectable Gastric Cancer.

Introduction: Trastuzumab deruxtecan (T-Dxd) has been approved for the treatment of HER2-positive gastric cancer. However, there are only a limited number of cases of gastric cancer where a long-term complete response (CR) has been maintained. Consequently, we report a case of gastric cancer in which long-term CR was maintained. Case Presentation: A woman in her late 60s underwent a gastrointestinal endoscopy, which revealed a type 2 lesion with ulceration in the lesser curvature of the vestibule, and a biopsy, which revealed an adenocarcinoma. Computed tomography (CT) revealed wall thickening of the gastric antecubital region, metastatic liver tumor, and extra-regional lymph node metastasis; a diagnosis of T4a, N3a, M1 (H, LYN), and cStage IVB (HER2 3+) was confirmed. Trastuzumab, oxaliplatin, and S-1 were administered initially. After 9 months, ascites appeared, and progressive disease was diagnosed. Paclitaxel and ramucirumab were started as second-line treatments but discontinued owing to neutropenia and increasing ascites. Third-line treatment with T-Dxd was initiated, and 11 months later, CT showed the disappearance of metastases. Even after 31 months, the CR was maintained. Conclusion: To the best of our knowledge, this is one of the few cases in which long-term CR was maintained with third-line T-Dxd treatment. Treatment strategies for patients with gastric cancer to achieve long-term CR require careful consideration.

Surgical strategies for localized colorectal amyloidosis.

BACKGROUND: Localized colorectal amyloidosis has a good prognosis, but cases involving bleeding or perforation may require surgery. However, there are few case reports discussing the differences in the surgical strategy between the segmental and pan-colon types. CASE PRESENTATION: A 69-year-old woman with a history of abdominal pain and melena was diagnosed with amyloidosis localized in the sigmoid colon by colonoscopy. Since preoperative imaging and intraoperative findings could not rule out malignancy, we performed laparoscopic sigmoid colectomy with lymph-node dissection. Histopathological examination and immunohistochemical staining revealed a diagnosis of AL amyloidosis (λ type). We diagnosed localized segmental gastrointestinal amyloidosis, because there was no amyloid protein in the margins, and the tumor was localized. There were no malignant findings. CONCLUSIONS: Unlike systemic amyloidosis, localized amyloidosis has a favorable prognosis. Localized colorectal amyloidosis can be classified into the segmental type, in which amyloid protein is deposited locally, and the pan-colon type, in which amyloid protein is deposited extensively in the colon. Amyloid protein causes ischemia due to vascular deposition, weakening of the intestinal wall due to muscle layer deposition, and decreased peristalsis due to nerve plexus deposition. No amyloid protein should remain outside the resection area. The pan-colon type is often reported to cause complications such as anastomotic leakage, and primary anastomosis should be avoided. On the other hand, if there is no contamination or tumor remnants in the margin, the segmental type may be considered for primary anastomosis.

Gastric volvulus associated with shrinkage of a gastrointestinal stromal tumor by neoadjuvant imatinib: a case report.

BACKGROUND: During neoadjuvant chemotherapy for giant gastrointestinal stromal tumors, changes in gastrointestinal stromal tumor size are rarely associated with events such as perforation and bleeding that require emergency surgery. Moreover, it is very rare for gastrointestinal stromal tumors to shrink and become mobile, resulting in gastric volvulus. Herein, we report a case of gastrointestinal stromal tumor shrinkage during neoadjuvant imatinib treatment, resulting in gastric volvulus that required surgery. To the best of our knowledge, this is the first reported occurrence of gastric volvulus during neoadjuvant imatinib treatment for a giant gastrointestinal stromal tumor. CASE PRESENTATION: A 58-year-old Japanese woman who was diagnosed with a giant gastric gastrointestinal stromal tumor and administered neoadjuvant imatinib presented to our hospital with complaints of abdominal pain and retching. Enhanced computed tomography revealed that the gastrointestinal stromal tumor had shrunk and shifted in position, and the stomach had organoaxially twisted. Accordingly, the patient was diagnosed with gastric volvulus caused by a gastric gastrointestinal stromal tumor. Conservative treatment did not improve the volvulus; hence, laparotomy was performed. The tumor developed from the lesser curvature of the stomach and caused rotation of the gastric body. The local gastric wall was resected. Histopathological examination confirmed the diagnosis of gastrointestinal stromal tumor. The patient received adjuvant imatinib for 3 years and has been alive for 5 years without recurrence. CONCLUSIONS: Gastric volvulus can be caused by the laxity of the ligaments that hold the stomach and gastric ptosis or esophageal hernia and diaphragmatic hernia; therefore, gastric gastrointestinal stromal tumors rarely cause gastric volvulus. However, a risk of torsion exists if the gastrointestinal stromal tumor develops extramural to lesser curvature and attains a certain size.

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

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

Utility of TMPRSS4 as a Prognostic Biomarker and Potential Therapeutic Target in Patients with Gastric Cancer.

BACKGROUND: Transmembrane serine protease 4 (TMPRSS4) belongs to the family of type II transmembrane serine proteases that are known to be upregulated in many malignant tumors. However, there is a paucity of studies documenting the clinical impact and biological effects of TMPRSS4 on gastric cancer (GC) patients who underwent surgery. METHODS: Tissues samples were obtained from 105 patients with GC who underwent gastrectomy followed by adjuvant chemotherapy, excluding those at stage I. The expression of TMPRSS4 was examined through immunohistochemical analysis. The association between TMPRSS4 expression and clinico-pathological features as well as prognosis was assessed. Moreover, the effects of TMPRSS4 expression on cell migration and sensitivity to 5-FU were investigated. RESULTS: The expression rate of TMPRSS4 was 56.3% (59/105) in GC cases. The expression of TMPRSS4 was positively correlated with the depth of tumor (T) and venous (V) invasion. The 5-year overall survival (OS) and recurrence-free survival (RFS) rates of the TMPRSS4-positive group was significantly lower than that of the TMPRSS4-negative group (p=0.0001 and p=0.005, respectively). Especially, there was significant differences in OS and RFS of patients with stage III cancer between the two groups (p=0.0064 and 0.012, respectively). Multivariate analysis demonstrated that TMPRSS4 expression and the stage of cancer were crucial prognostic factors for RFS. TMPRSS4-silenced GC cells exhibited increased sensitivity to 5-FU when compared with the non-specific control siRNA-transfected cells. CONCLUSION: TMPRSS4 can be considered as a potential prognostic biomarker, especially for stage III, and a promising therapeutic target for GC.

Clinical complete response after nivolumab administered as a third-line treatment for unresectable advanced gastric cancer with peritoneal dissemination: A case report.

INTRODUCTION AND IMPORTANCE: Nivolumab, which is a fully human IgG4 PD-1 immune checkpoint inhibitor antibody, has been recommended as a third-line treatment based on the results of the ATTRACTION-2 study involving patients with unresectable advanced gastric cancer. CASE PRESENTATION: A 69 year-old woman was referred to our department with a diagnosis of gastric cancer based on an upper gastrointestinal endoscopy during a medical examination. The endoscopy, along with various tests, helped establish a diagnosis of unresectable advanced gastric cancer (cT4aN3aM1P1c, cStage IV) with peritoneal dissemination. The first and second-line chemotherapy administered was S-1 plus oxaliplatin followed by ramucirumab and nab-paclitaxel, respectively. In this case, the disease was evaluated as progressive disease due to increased peritoneal dissemination. Nivolumab was administered as the third-line treatment. The patient developed interstitial pneumonia after nine courses of nivolumab, for which chemotherapy was discontinued and prednisolone treatment was initiated. The patient had a complete response to treatment endoscopically, 9 months after the last administration of nivolumab. After that, there was no recurrence of the cancer, despite there being no treatment for 5 months. CLINICAL DISCUSSION: It was suggested that the therapeutic effect of nivolumab could be maintained for a long period after discontinuation of its administration. In addition, a correlation has been reported between the treatment efficacy and immune-related adverse events associated with nivolumab. CONCLUSIONS: The synergistic effect of the sustained effect of nivolumab and later-line treatment may contribute to the prolongation of survival after discontinuation of nivolumab in patients who are refractory or intolerant to treatment.

Laparoscopic resection for a large gastrointestinal stromal tumor (GIST) with diaphragm invasion following preoperative imatinib treatment: A case report.

INTRODUCTION: Neoadjuvant imatinib for large GISTs may prevent tumor rupture and the need for extended surgery by reducing tumor size. In this study, we present a case of large gastric GIST with diaphragm invasion, due to the patient receiving laparoscopic resection following preoperative imatinib treatment. PRESENTATION OF CASE: A 72-year-old woman was hospitalized with left hypochondriac pain for a month. Examinations revealed a large heterogeneous gastric mass measuring 80 mm in size, arising from the greater curvature of the corpus. The mass invaded the left thoracic diaphragm. Treatment with imatinib at an initial dosage of 400 mg/day was initiated. After a further two months of follow-up, the lesion had sustained reduction to 50 mm in size, however, the invasion to the diaphragm remained. The patient eventually underwent laparoscopic partial gastrectomy and partial resection of the diaphragm with curative intent. Adjuvant chemotherapy was initiated at one month after the surgery, however, was discontinued due to nausea. After one-year follow-up, no recurrence was noted. DISCUSSION: Neoadjuvant imatinib may shrink tumor size remarkably and prevent tumor rupture during surgery, and thus lead to increased rates of complete resection. To date, several publications have directly compared the oncologic results between laparoscopic and open resection for GISTs. In the present case, the tumor was movable, and moderately fixed on diaphragm. It was favorable condition for laparoscopic surgery. CONCLUSIONS: This is the first report of a large gastric GIST invading the diaphragm that was successfully treated by laparoscopic resection after tumor reduction by neoadjuvant imatinib.

Gastric adenocarcinoma appearance in leiomyoma: A case report.

INTRODUCTION: We experienced an extremely rare case of gastric adenocarcinoma wrapped by leiomyoma. PRESENTATION OF CASE: A 65-year-old man had an abnormality (filling defect) of the upper gastrointestinal series in his first medical checkup five years prior. Esophagogastroduodenoscopy detected a 10 mm submucosal tumor-like lesion in the greater curvature of the upper gastric remnant body. Despite repeated biopsy from the lesion, there was no sign of malignancy. A delle was observed on the top of the tumor at another visit five year after the first and a biopsy specimen revealed poorly differentiated adenocarcinoma. Therefore, laparoscopic gastrectomy was performed. Histological assessment revealed a 28 × 22 mm elevated lesion with a slight depression. Microscopically, papillary adenocarcinoma was observed at the submucosa with a solitary heterotopic gastric gland adjacent to the lesion. The final diagnosis was papillary adenocarcinoma arising from a solitary heterotopic gastric gland in the leiomyoma. No recurrence has occurred during a follow-up of two and a half years after surgery. CONCLUSIONS: This is the first report of gastric adenocarcinoma arising from a submucosal tumor.

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

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

A Case of Advanced Gastric Cancer with Peritoneal Metastasis Treated Successfully with Nivolumab.

Peritoneal metastasis (PM) is detected in 14% of gastric cancers at the time of initial diagnosis, with a median survival time of 4 months. A 66-year-old woman diagnosed with cT4a(SE) N2M1(LYN) cStage IV was treated with three lines of chemotherapy for a year. During the third line of chemotherapy, computed tomography (CT) scan revealed a large amount of ascites, periportal collar sign, and bilateral ureteral stenosis owing to PM. The tumor biomarkers (CEA and CA 19-9) remained elevated similar to the initial levels. The patient was administered 3 mg/kg nivolumab intravenously biweekly as the fourth line of chemotherapy. Three months after the nivolumab treatment, gastroscopy revealed an extreme reduction of the tumor size, while CT scan revealed the absence of ascites and a well-controlled tumor. There was no immune-related adverse event with nivolumab during and after the treatment, and performance status improved to 0. The patient has been alive for about 2.5 years since her first visit with her sixth line of chemotherapy (docetaxel). We report a case of advanced gastric cancer with PM that was treated successfully with nivolumab.

Successful surgical management of non-perforating acute appendicitis with septic disseminated intravascular coagulation: A case report and review of the literature.

INTRODUCTION: Perforating appendicitis and abscess-forming appendicitis may cause septic disseminated intravascular coagulation (DIC). However, non-perforating acute appendicitis with septic DIC is extremely rare. PRESENTATION OF CASE: A 67-year-old man was referred to our hospital one day after starting oral antibiotic treatment for acute appendicitis. Physical examination revealed only slight spontaneous abdominal pain without tenderness and peritoneal irritation. Contrast-enhanced computed tomography demonstrated an enlarged appendix (10 mm in diameter) without fecalith, ascites, intraperitoneal free air, and abscess. There was no evidence of perforating appendicitis. Laboratory analysis revealed septic DIC. The patient was diagnosed with non-perforating acute appendicitis with septic DIC. The patient was distressed regarding whether he should be treated conservatively with an antibiotics-first strategy or undergo an appendectomy. Ultimately, a laparoscopic appendectomy was performed. Histopathological examination showed non-perforating gangrenous appendicitis. He required DIC therapy for 2 days postoperatively. He was discharged on postoperative day 9, and remained in good health 1 month after surgery. DISCUSSION: There is no absolute index of conversion to surgery with an antibiotics-first strategy of appendicitis treatment. Judging the limit of conservative treatment and determining the best moment to perform surgery is a critically important matter for patients with acute appendicitis. CONCLUSIONS: The incidence of conservative treatment preceding an antibiotics-first strategy for acute appendicitis is increasing. However, it is thought that appendectomy should be performed when acute appendicitis is complicated with septic DIC, even if it is a non-perforating appendicitis in which improvement with conservative treatment is anticipated.

Appendiceal neurofibroma with low-grade appendiceal mucinous neoplasm in neurofibromatosis type 1 patient: A case report.

INTRODUCTION: Neurofibromas are a characteristic of the autosomal dominant disorder Neurofibromatosis type 1 (NF1), also known as von Recklinghausen's disease. Appendiceal neurofibromas are extremely rare, and low-grade appendiceal mucinous neoplasms (LAMNs) have not previously been reported in NF1. PRESENTATION OF CASE: A 62-year-old man with NF1 was scheduled for elective surgical treatment of an asymptomatic, enlarged and diffusely thickened appendix that remained after curative antimicrobial treatment of acute appendicitis. Laboratory analysis revealed all normal. Colonoscopy showed thickened appendiceal mucosa projecting into the cecum. A sample of the mucosa was found to be pathologically benign. The patient was preoperatively diagnosed with treated acute appendicitis with chronic appendiceal inflammation versus appendiceal neoplasms. Laparoscopic cecectomy was performed. Multiple neurofibromas were observed in the muscle layer, submucosa, and mucosa of the appendix on histopathological examination. Immunohistochemical examination showed positive staining for S-100. Pathologically, the patient was diagnosed with appendiceal neurofibroma consistent with NF1 with LAMNs. His postoperative course was unremarkable. He was discharged on post-operative day 3 and remained in good health 7 month after surgery. CONCLUSIONS: Appendiceal neurofibromas are often preoperatively diagnosed as appendicitis. Appendiceal neurofibromas should be considered in patients with NF1 who are suspected of having appendicitis.

Intestinal obstruction caused by low-grade appendiceal mucinous neoplasm: A case report and review of the literature.

INTRODUCTION: Intestinal obstructions due to appendiceal pathology are rare. Obstructions caused by low-grade appendiceal mucinous neoplasms (LAMNs) are rarer still. PRESENTATION OF CASE: A 79-year-old woman was referred to our hospital for mechanical small intestinal obstruction. The patient had undergone prior left oophorectomy via a lower abdominal incision. Physical examination revealed abdominal distension and slight tenderness. Laboratory analysis was unremarkable. Contrast enhanced computed tomography (CT) demonstrated dilation of an obstructed small intestinal loop without evidence of strangulation. There appeared to be a low density mass measuring 3.0 × 1.5 cm with a potential twist in the mesentery near the transition point in the small intestine. The patient was diagnosed with mechanical small intestinal obstruction and was treated conservatively with nasogastric tube decompression for one week. After no clinical improvement, we elected to surgically explore her. Intraoperative findings revealed that the ileum was compressed by the appendix, which had a cystic mass on its tip. There was no evidence of intestinal ischemia. Laparotomy appendectomy alone was performed. Pathology revealed a LAMN measuring 3.0 × 1.5 cm. She remains disease-free with 18 months of postoperative follow-up. DISCUSSION: Intestinal obstruction due to external compression by an appendiceal mass is rare, and is often difficult to preoperatively diagnose with CT. CONCLUSIONS: The etiology of small intestinal obstruction with a transition point in the right lower quadrant of abdomen includes an appendiceal mass on the broad differential for this common problem.

Pancreatobiliary fistula associated with intraductal papillary mucinous carcinoma accompanying obstructive jaundice: A case report.

INTRODUCTION: Intraductal papillary mucinous neoplasms (IPMNs) occasionally involve formation of fistulas with other adjacent organs. Pancreatobiliary fistulas associated with IPMNs are rare, but affected patients often develop obstructive jaundice and cholangitis. PRESENTATION OF CASE: A 79-year-old man was referred to our hospital for evaluation of abnormal biliary enzymes. Contrast-enhanced computed tomography and endoscopic retrograde cholangiopancreatography demonstrated multiple cystic lesions with septa in the pancreatic head and fistulas between the cystic lesions and common bile duct. The clinical diagnosis was pancreatobiliary fistula associated with a mixed-type IPMN and accompanying obstructive jaundice. The patient underwent subtotal stomach-preserving pancreaticoduodenectomy. The resected specimen showed fistulas between the cystic lesions and common bile duct. Histopathological examination showed that the main and branch ducts of the pancreatic head were dilated and filled with mucus. The epithelia of the pancreatic ducts revealed papillary proliferation and an invasive adenocarcinoma arising from an intraductal neoplasm. Immunohistochemistry examination showed CDX2- and MUC2-positive reactions. The final diagnosis was an intraductal papillary mucinous carcinoma of the intestinal-type. The patient remained disease-free for 9 months postoperatively. DISCUSSION: The causes of death in patients who have pancreatobiliary fistulas associated with IPMNs without resection are cholangitis or hepatic insufficiency. Nonoperative treatment is limited for cases with obstructive jaundice. It is necessary to prevent obstructive jaundice and cholangitis due to a large quantity of mucinous material. CONCLUSIONS: Surgical resection should be considered, if possible, in patients with pancreatobiliary fistulas associated with IPMNs. A better prognosis is expected with prevention of obstructive jaundice or cholangitis.

Mixed adenoneuroendocrine carcinoma of the distal bile duct: A case report.

INTRODUCTION: Mixed adenoneuroendocrine carcinomas (MANECs) of the distal bile duct are extremely rare, and only a few cases have been reported in the English literature. PRESENTATION OF CASE: An 82-year-old man was referred to our hospital for increasing biliary enzymes. Abdominal computed tomography (CT) showed enlargement of the intrahepatic bile ducts and stenosis of the distal bile duct. Endoscopic retrograde cholangiopancreatography showed stenosis of the distal bile duct and a high-density signal at the same site on diffusion weighted imaging. PET-CT showed increased FDG accumulation (SUVmax: 4.5) at the distal bile duct stenosis. Biopsy specimens obtained by endoscopic ultrasonography-guided fine-needle aspiration revealed adenocarcinoma. The patient was diagnosed with adenocarcinoma of the distal bile duct and underwent subtotal stomach-preserving pancreaticoduodenectomy with regional lymph node dissection. The resected distal bile duct tumor was 18×14×12mm in diameter. Hematoxylin and eosin staining revealed a composite carcinoma with adenocarcinoma and non-adenocarcinoma elements. The non-adenocarcinoma component stained positive for synaptophysin and chromogranin A. The Ki-67 labeling index was 37%. The non-adenocarcinoma component was therefore diagnosed as a neuroendocrine carcinoma. The two composite carcinoma was diagnosed as MANEC of the distal bile duct. The patient was treated with surgery alone and he remained disease-free for 7 months after the surgery. DISCUSSION: The treatment of MANECs of the bile duct remains controversial and the prognosis is poor. CONCLUSIONS: There is no standard treatment for MANECs of the bile duct. Larger studies are required to establish standard treatment regimens.

Splenic hamartoma associated with thrombocytopenia: A case report.

INTRODUCTION: Hamartomas are rare, benign tumors of the spleen. Few cases of splenic hamartomas associated with thrombocytopenia have been reported. PRESENTATION OF CASE: An asymptomatic 64-year-old man with myelodysplastic syndrome was found to have a splenic tumor. Laboratory tests were significant for thrombocytopenia, with a platelet count of 7.8×104/µL. Ultrasonography showed splenomegaly (10.8×6.6cm), and a hypoechoic splenic mass (8.0×7.0cm). Color doppler ultrasound revealed blood flow within the mass, and the mass density was homogeneous on abdominal computed tomography (CT). Contrast-enhanced CT showed heterogeneous enhancement of the splenic mass during the arterial phase. Positron emission tomography (PET)-CT showed no significant fludeoxyglucose (FDG) accumulation within the mass. The differential diagnosis included splenic hamartoma, splenic hemangioma, splenomegaly associated with extramedullary hematopoiesis, and malignant tumor, including solitary splenic metastasis. A laparoscopic splenectomy was performed due to the possibility of malignancy, the presence of thrombocytopenia, and the risk of splenic rupture. The resected specimen showed a localized, well-demarcated, 8.0×7.0cm splenic mass. Histological examination revealed abnormal red pulp proliferation and the absence of normal splenic structures. The patient's post-operative course was uneventful. His platelet count improved on post-operative day 1 and he was discharged on post-operative day 9. He remained in good health with a normal platelet count one month after surgery. DISCUSSION: Making definitive preoperative diagnosis is difficult in splenic hamartomas. Surgery is necessary for diagnosis when malignancy cannot be ruled out. CONCLUSIONS: Surgery may also improve symptoms of hypersplenism, including thrombocytopenia.

[Abdominoperineal Resection for Anal Metastasis of Rectal Cancer].

Anal metastasis of colorectal cancer is rare, and no standardized effective therapeutic strategy exists. We report a case of abdominoperineal resection for anal metastasis of rectal cancer. A 65-year-old man underwent laparoscopic low anterior resection for rectal cancer in August 2013. Histopathological examination revealed a moderately differentiated adenocarcinoma( tub2, pSS, ly3, v2, pN1, H0, P0, M0, Stage III a, Cur A). In February 2015, he complained of anal discomfort, and tumor markers were elevated. Enhanced CT revealed a 15-mm high-density solid tumor in the anal canal. The results of needle biopsy indicated a moderately differentiated adenocarcinoma. This tumor was suspected to be metastasis from rectal cancer, and we performed abdominoperineal resection. Histopathological examination revealed a moderately differentiated adenocarcinoma, which was the same histological type as the primary rectal cancer and was covered with normal anal epithelium. Collectively, the findings indicated anal metastasis from rectal cancer. The patient is alive without recurrence for 18 months after resection. Anal metastasis should be considered as a differential diagnosis in patients with anal discomfort who have a history of colon/rectal cancer. Abdominoperineal resection may be an effective treatment modality for this condition.

Prognostic Impact of Para-Aortic Lymph Node Micrometastasis in Pancreatic Ductal Adenocarcinoma.

BACKGROUND: It is still unclear whether micrometastasis of para-aortic lymph nodes (PALNs) in pancreatic ductal adenocarcinoma (PDAC) is tantamount to PALN metastasis detected by hematoxylin and eosin (HE) staining. METHODS: A total of 242 patients with PDAC who underwent radical pancreatectomy with PALN dissection were eligible for this study. Micrometastasis in PALNs was evaluated by CAM 5.2 immunohistochemistry. The relationship between PALN status and overall survival (OS) was analyzed. RESULTS: Of the 242 enrolled patients, 25 (10 %) had PALN metastasis detected by HE (PALN HE-positive), and 21 (9 %) had PALN micrometastasis not detected by HE but identified by CAM 5.2 immunohistochemistry. Univariate analysis revealed that patients with PALN micrometastasis (p = .004) and PALN HE positivity (p = .003) had a significantly shorter OS than those without PALN metastasis, whereas no significant difference was observed between the two former groups (p = .874). In multivariate analysis, lack of adjuvant chemotherapy (hazard ratio [HR] 2.43, p < .001), PALN micrometastasis (HR 1.89; p = .046), and PALN HE-positivity (HR 1.89, p = .023) were identified as independent risk factors for poor prognosis. Within a subset of 46 patients with PALN HE-positivity or micrometastasis, lack of adjuvant chemotherapy was independently associated with poor OS (HR 2.58. p = .029). CONCLUSIONS: The prognosis of patients with PALN micrometastasis was extremely poor as well as HE-positive PALNs. However, postoperative adjuvant chemotherapy may contribute to improving the prognosis of PDAC patients with PALN metastasis.