Polypoid gallbladder neuroendocrine tumor diagnosed as benign polyp before surgery: A case report.

Gallbladder neuroendocrine tumors (GB-NETs) comprise only 0.5% of all NET cases, and their biology has been incompletely characterized. In the present study we report the case of a 50-year-old male patient with GB-NET who was admitted to Naito Hospital with diarrhea as the main complaint. At initial diagnosis, serum carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) levels were within the normal range. Abdominal ultrasonography and contrast-enhanced computed tomography (CT) revealed gallbladder adenomyomatosis and cholecystitis, and an 8-mm pedunculated polypoid lesion was found in the neck of the gallbladder using drip infusion cholecystocholangiography-CT. As it was considered a benign polyp, laparoscopic cholecystectomy was performed. Pathological examination revealed a polypoid lesion that comprised NET cells with a cord-like or ribbon-like arrangement, and the cells exhibited positive immunostaining for chromogranin A and synaptophysin. In addition, immunohistochemical staining showed a Ki-67 index (i.e., proliferation index) of <1%, and no necrosis or mitotic figures were observed in the background. Based on these observations, we diagnosed the following: GB-NET, G1, 10x12 mm in size and located in the gallbladder neck. According to the World Health Organization 2010 classification, NET G1 is a well-differentiated tumor, with the tumor cells having a low proliferative potential [Ki-67 index ≤2%; mitotic figure number <2 (/10 HPF)]. It is regarded as a low- to mild-grade malignancy. Low-grade GB-NET occurs relatively rarely, and no clear guidelines have been formulated regarding its surgical treatment, such as minimal surgical excision margins or lymph node dissection. Detailed treatment recommendations should be developed after systematic studies of additional cases of GB-NET.

Efficacy of peritoneovenous shunt for treating tolvaptan-resistant refractory ascites in a cirrhotic patient with portal vein thrombosis: A case report.

Peritoneovenous shunt is normally used for the treatment of refractory ascites. However, its efficacy in treating tolvaptan-resistant refractory ascites has not been reported thus far. In addition, the impact of peritoneovenous shunt on the prognosis of cirrhotic patients remains controversial. In the present report, a case of tolvaptan-resistant refractory ascites associated with liver cirrhosis and portal vein thrombosis is described. The male patient was diagnosed with hepatitis C virus-related liver cirrhosis at the age of 51 years. At the age of 56 years, the patient developed portal vein thrombosis, resulting in the development of refractory ascites. Since the ascites was resistant to treatment with a low-sodium diet and diuretics such as tolvaptan, a peritoneovenous shunt was implanted upon obtaining consent. The shunt immediately increased the urine volume, and the ascites was markedly decreased. The patient's body weight decreased from 62.7 to 57.1 kg in 2 days, and his ascites symptom inventory-7 score decreased from 23 to 0 points in 31 days. Although the patient succumbed to sepsis on day 486 following the shunt implant, his activities of daily living were preserved until 8 days prior to mortality. Thus, the present case supports the efficacy of peritoneovenous shunt for the treatment of tolvaptan-resistant refractory ascites associated with liver cirrhosis and portal vein thrombosis. Furthermore, the present case suggests that peritoneovenous shunt may prolong the survival of cirrhotic patents with refractory ascites.

Guide to diagnosing primary pancreatic lymphoma, B-cell type: immunocytochemistry improves the diagnostic accuracy of endoscopic ultrasonography-guided fine needle aspiration cytology.

Primary pancreatic lymphoma (PPL) is a rare disease with <1%of extranodal non-Hodgkin's lymphoma arising in the pancreas. This report provides immunocytochemical information on PPL that would be valuable for making differential diagnoses between PPL, pancreatic neuroendocine tumor, acinar cell carcinoma, and pancreatic ductal cancer. A 68-year-old woman had a chief complaint of abdominal pain. Fine needle aspiration cytology (FNAC)was performed. The FNAC smear showed moderate cellularity,with a small to moderate number of irregular cells and lymphocytes.No epithelial tumor clusters or abundant mucoid background were seen. The cells were scattered with pleomorphism and showed irregular nuclear shapes with finely granular chromatin,an increased nuclei­cytoplasm ratio, and prominent nucleoli.Cytologically, PPL was suspected with Papanicolaou staining but definite diagnosis was not made. Therefore, the specimen was destained, immunocytochemically examined for leukocyte common antigen (LCA), and PPL was suspected again. Numerous tumor cells were found in the surgical sample and tumor cells were positive for CD20 and negative for CD45RO. Based on these findings,the tumor was diagnosed as PPL, B-cell type. The preoperative FNAC smear that was examined for LCA was then reexamined for CD20, CEA, and Synaptophysin. As a result, the tumor cells were positive for LCA and CD20, whereas they were negative for CEA and Synaptophysin. Taking these findings together with the cytopathologic findings, this specimen was reconfirmed as PPL. Immunocytochemical examination for LCA and CD20 is useful in the identification of malignant pancreatic lymphoma, B-cell type.

A case of IgG4-related sclerosing mesenteritis.

IgG4-related disease has been recognized as a systemic syndrome characterized by mass-forming lesions with lymphoplasmacytic infiltration and sclerosis. This disease has been identified in various sites, including the pancreas, retroperitoneum, lung, head, and neck. Herein we report a case of IgG4-related sclerosing mesenteritis. An 82-year-old woman was admitted to our hospital due to persistent abdominal pain. Abdominal computed tomography demonstrated a solitary mass with a maximal diameter of 11.7cm in mesentrium of the small intestine. On her laboratory examination, only C-reactive protein level was elevated. Although the pre-operative diagnosis was indefinite, she underwent ileocecectomy. Grossly, an elastic soft mass with foci of hemorrhage was seen in the mesentrium. Microscopically, the lesion was composed of fibroblastic or myofibroblastic spindle cells with abundant stromal fibrosis and inflammatory infiltrate, such as lymphocytes and plasma cells accompanied by lymphoid follicles with a germinal center. Obstructive phlebitis was observed. Immunohistochemically, numerous IgG4-positive plasma cells were observed, and the IgG4/IgG ratio was 75.9%. The serum level of IgG4 examined at post-operation was high. These findings suggested that this lesion was consistent with IgG4-related sclerosing mesenteritis.

Multi-centric pancreatic cancer without PanIN lesion.

The patient was a 67-year-old man under follow-up after gastric cancer surgery. An abdominal CT scan performed 1 year earlier had shown an approximately 14-mm hypovascular mass in the pancreatic body; however, he did not consent to treatment and was followed up for 1 year. A blood workup showed that the fasting blood glucose level, which had been within normal limits, was elevated to 174 mg/dl (normal, 70-109 mg/dl), and the HbA1c level was 12.0% (normal, 4.3-5.8%). Abdominal CT revealed an approximately 20-mm mass in the pancreatic body and an approximately 12-mm mass in the pancreatic tail, and magnetic resonance imaging cholangiopancreatography (MRCP) showed discontinuity of the main pancreatic duct (MPD). Since these findings led to the suspicion of invasive ductal carcinoma (IDC) of the pancreas developing in the pancreatic body and tail, we performed distal pancreatectomy with splenectomy. Histologically, IDCs were observed in the pancreatic body and tail. However, PanIN was not observed in the MPD between the two carcinomas. They were diagnosed as independent invasive ductal carcinomas of the pancreas.