Acute necrotic disorder of the small intestine post-coronavirus disease-2019 vaccination.

The Pfizer-BioNTech coronavirus disease 2019 (COVID-19) vaccine is extensively used worldwide, and its safety has been proven. Herein, we report a case of an acute necrotic disorder in the small intestine post-COVID-19 vaccination. The patient developed severe abdominal pain the day after the first vaccination. Contrast-enhanced computed tomography showed extensive ileum wall thickening and ascites. Colonoscopy revealed a ring-shaped ulcer and stricture in the terminal ileum. Ileocecal resection was performed, and the patient did not have further episodes of a necrotic disorder in the small intestine. Although it is unknown if this event is associated with vaccination, and this occurrence also does not outweigh the efficacy and safety of the Pfizer-BioNTech COVID-19 vaccine, gastroenterologists need to be aware of this rare case, given its noteworthy timing.

A case of mixed adenoneuroendocrine carcinoma of the pancreas mimicking intraductal papillary mucinous carcinoma.

A previously healthy 52-year-old man was referred to our hospital for further evaluation of main pancreatic duct dilatation. The preoperative work-up was consistent with intraductal papillary mucinous carcinoma (IPMC) derived from a mixed type intraductal papillary mucinous neoplasm (IPMN), because multilocular cysts with enhancing thickened pancreatic head walls and dilated pancreatic ducts lined with dysplastic mucinous epithelium, with papillary proliferation from the pancreatic body to the tail, were observed; in addition, the pancreatic juice cytology was class V, which is suggestive of adenocarcinoma. Total pancreatectomy was performed because a definite mass was not found before surgical resection and the tumors could have spread to the tail. The pathological diagnosis was mixed adenoneuroendocrine carcinoma of the pancreatic head. IPMN with high- or low-grade dysplasia was not observed anywhere in the pancreatic duct. The pancreatic ductal adenocarcinoma consisted of large caliber malignant glands with intraluminal flat or papillary structures; therefore, we were unable to recognize a definite pancreatic mass before surgical resection, and suspected an IPMC derived from a mixed type IPMN.

Methotrexate-associated primary hepatic malignant lymphoma following hepatectomy: A case report.

INTRODUCTION: Recently, immunosuppressant-associated malignant lymphoma (ML) cases have been increasing along with the development of several effective immunosuppressant drugs for rheumatoid arthritis (RA). Among methotrexate (MTX)-associated lymphoproliferative disorders, primary hepatic lymphoma (PHL) in patients with RA following surgical resection has not been reported previously. PRESENTATION OF CASE: A 65-year-old woman who is a hepatitis B virus carrier with a history of RA was admitted. MTX was introduced seven years prior as an RA treatment. Her laboratory data showed no elevation of several tumor markers, and liver function test results were normal. On contrasted computed tomography (CT) scanning, a slightly enhanced tumor was detected at the early phase, and tumor staining was sustained at the delayed phase. Further, subsegmentectomy of the S6 was performed. The pathological diagnosis was diffuse large B-cell lymphoma. However, positron emission tomography-CT and bone marrow aspiration sample showed no resident sign of ML. DISCUSSION: Diagnosis of PHL before surgery is difficult. If the mass lesion was solitary and had a certain degree of size, then resection could be performed for its treatment and diagnosis. The treatment for ML requires a diagnosis of the subtypes to select a therapeutic agent and determine the prognosis. Once a precise preoperative diagnosis was made, withdrawing MTX could be the first treatment in case of MTX-related ML. CONCLUSION: Long-term usage of immunosuppressant drugs could cause proliferative ML. Considering the increasing occurrence of MTX-related ML, withdrawing MTX should be considered, especially in patients with long-term immunosuppressant usage for RA.

A case report on metastatic pancreatic tumor from pulmonary adenocarcinoma that difficult to differentiate from primary pancreatic ductal carcinoma.

A woman was admitted to our department for lung adenocarcinoma and she was treated with left upper lobectomy. The carcinoembryonic antigen level had increased. Enhanced computed tomography showed a hypovascular tumor in the pancreatic tail and in the extension of the distal main pancreatic duct. Endoscopic ultrasonography (EUS) clearly showed a low echoic lesion, and histological examination revealed adenocarcinoma. On immunostaining, the lesion was diagnosed as metastatic adenocarcinoma of the lungs. The patient was treated with chemotherapy for lung cancer and survived for 4 years after diagnosis. Differentiating a metastatic lesion to the pancreas from pancreatic ductal adenocarcinoma is very important. Accurate diagnosis enables administration of appropriate treatment. In this case, EUS was especially useful for assessing the tumor in the pancreas. When patients with a history of extra-pancreatic cancer present with a pancreatic lesion, pancreatic metastases should be considered, regardless of the time elapsed since occurrence of the primary cancer. EUS-fine needle aspiration (FNA) with histological examination is the best method for definitive diagnosis of pancreatic disease in this group of patients. This approach has very high sensitivity and accuracy for the diagnosis of pancreatic metastases.

Effective screening for early diagnosis of pancreatic cancer.

Diagnosis of pancreatic cancer (PC) at an early stage with curative surgery should improve long-term patient outcome. At present, improving survival should lie in identifying those cases with high-risk factors or precursor lesions through an effective screening including ultrasonography, some biological markers, or national familial pancreatic cancer registration. Recently, cases with PC < 10 mm with a favorable prognosis have been reported. For the diagnoses of cases with PC < 10 mm, the rate of tumor detection was higher on endoscopic ultrasonography (EUS) than on CT or other modalities, and EUS-guided fine needle aspiration was helpful in confirming the histologic diagnosis. Additionally, for the diagnosis of cases with PC in situ, EUS and magnetic resonance cholangiopancreatography (MRCP) may play important roles in detecting the local irregular stenosis of the pancreatic duct. Cytodiagnosis of pancreatic juice using endoscopic nasopancreatic drainage multiple times may be useful in the final diagnosis.

Diagnostic strategies for early pancreatic cancer.

Diagnosis of pancreatic cancer (PC) at an early stage with curative surgery is the approach with the potential to significantly improve long-term patient outcome. Recently, some reports showed that patients with pancreatic tumors smaller than 10 mm showed a favorable prognosis. However, the rate of tumor detection on computed tomography in patients with small pancreatic tumors is low. For the diagnoses of PC with tumors smaller than 10 mm, the rate of tumor detection was higher on endoscopic ultrasonography (EUS) than on computed tomography or other modalities, and histologic diagnosis using EUS-guided fine-needle aspiration was helpful in confirming the diagnosis. For the diagnosis of PC in situ, EUS and magnetic resonance cholangiopancreatography may play important roles in detecting the local irregular stenosis of the pancreatic duct. Endoscopic retrograde pancreatography and sequential cytodiagnosis using pancreatic juice obtained by endoscopic nasopancreatic drainage multiple times was useful in the final diagnosis of PC in situ. At present, improving survival lies in identifying those individuals with high-risk factors or precursor lesions through an effective screening method. For example, these should include ultrasonography, various biological markers, or national familial pancreatic cancer registration. Additionally, the relationship between specialists in PC from medical centers and practicing physicians plays an important role in the early diagnosis of PC.

Percutaneous transhepatic sclerotherapy for recurrent bleeding ileal varices diagnosed by capsule endoscopy and computed tomography during percutaneous transhepatic venography.

We report a case of acute uncontrolled gastrointestinal bleeding in a patient with liver cirrhosis. A 64-year-old man was admitted to our hospital for further investigation of blood in stools. Preliminary examination by computed tomography (CT) as well as upper and lower endoscopy could not detect the bleeding source. Exploratory laparotomy was considered difficult due to potential easy bleeding and adhesions caused by past abdominal surgery. The hemoglobin level was normalized by blood transfusion. Capsule endoscopy (CE) identified ileal varices. The top of these ileal varices was red, prompting their identification as the source of bleeding. Percutaneous transhepatic venography (PTV) confirmed the presence of many varices in the branch of the superior mesenteric vein, although the bleeding source could not be identified. CT during PTV identified varices protruding into the ileal lumen, which were managed subsequently by percutaneous transhepatic sclerotherapy (PTS). The procedure stopped the bleeding completely. CE proved less invasive and effective in detecting obscure gastrointestinal bleeding. CT during PTV followed by PTS is suitable for diagnosis and treatment of bleeding varices in patients with portal hypertension.

[A case of mucosal Schwann cell hamartoma].

A 40-year-old man was referred to our hospital because of a positive fecal occult blood test. Colonoscopy revealed many small whitish nodules in the mucosa of the sigmoid colon. Specimens endoscopically resected from the lesions revealed spindle cell proliferation in the lamina propria. Immunohistochemical study revealed strong and diffuse positivity for S-100 protein. Results of staining for neurofilament protein and epithelial membrane antigen were negative. The neurogenic tumors were diagnosed as mucosal Schwann cell hamartoma. No clinical features of multiple endocrine neoplasia type 2B or neurofibromatosis type 1 were found in the present case.

A case of Helicobacter pylori-negative depressed type gastric adenoma.

A 75-year-old woman was referred to our hospital for further examination of gastric antral abnormal endoscopic findings. Endoscopic study of the stomach revealed a depressed lesion in the gastric antrum. Atrophic findings were not recognized in the background gastric mucosa, and Helicobacter pylori infection was not detected by histology, an urea breath test, a rapid urease test and serological test. A diagnosis of adenoma was given histopathologically from the resected specimens. As a result of immunohistological study, the phenotype of the tumor was not classified as either gastric type or intestinal type. CDX2 was positive in part of the tumor.