Delayed perforation after cold snare polypectomy for small colonic polyps in a patient receiving oral corticosteroids.

This case report describes a fatal outcome due to delayed perforation after cold snare polypectomy in a patient with bullous pemphigoid receiving oral corticosteroids. Cold snare polypectomy has become the standard treatment for small colorectal polyps because of the procedure's safety and simplicity. In this case, however, corticosteroid therapy and vasculitis may have caused local necrosis and tearing of the intestinal wall. Corticosteroids are widely used, and perforation after cold snare polypectomy is extremely rare. However, some patients on corticosteroid therapy may have special pathologies, such as in this case, and we advise physicians to use appropriate judgment and extreme caution in determining the indication for endoscopic therapy.

Genomic analysis of an aggressive case with metastatic intrahepatic mucinous cholangiocarcinoma.

Intrahepatic mucinous cholangiocarcinoma (IHMC) is rare and behaves notoriously; however, the details of the clinicopathological characteristics of IHMC remain unknown. A 70-year-old man was admitted for examination of the hepatic mass in the S1 segment. He underwent extended left hepatic lobectomy. Histopathological evaluation demonstrated mixed papillary carcinoma that comprised well to moderately differentiated tubular adenocarcinoma and signet-ring cell carcinoma with large amounts of mucus lakes. Tumor was relapsed 9 months after surgery. Although he received chemotherapy with the combination of gemcitabine and cisplatin, he had renal failure and discontinued the chemotherapy. He received palliative radiotherapy for metastasis in the cervical spine. Then, the patient treated with S-1, however, he died 16 months after the initial diagnosis. The autopsy findings showed multiple nodules in the lungs, pleura, kidneys, adrenal glands, stomach, pancreas, and lymph nodes. Histological examination revealed that all nodules were IHMC. Next-generation sequencing revealed that somatic mutations in ADGRB3, TAF1L and EPHA3 may affect carcinogenesis, and those in TAF1, EPHA3, PIK3C2B, FN1, ERBB3, BRIP1, SYNE1 and TGFBR2 may affect metastasis. Molecular carcinogenesis of IHMC may be distinct from that of ordinary cholangiocarcinoma. Further studies are needed to elucidate the genetic mutations and their functions in IHMC.

[A Case in Which Multiple Post-Operatively Recurring Hepatocellular Carcinomas Showed a Positive Response to Sorafenib-Hepatic Arterial Infusion Chemotherapy (HAIC)Sequential Therapy].

A male patient in his 70s underwent a right lobectomy because of a hepatocellular carcinoma(HCC)located in the right lobe(S6)of his liver. Eleven months after surgery, contrast-enhanced CT showed multiple masses in the residual liver, which were diagnosed as HCC recurrence. He was then treated with hepatic arterial infusion chemotherapy(HAIC). Ten months after the recurrence, the liver tumors progressed. Therefore, treatment was switched to sorafenib(400 mg/day orally)and HAIC(low-dose FP: 5-FU 250 mg plus CDDP 5 mg 5 days/week 4 weeks)sequential therapy. The patient received 2 cycles of sorafenib-HAIC sequential therapy for 11 months, and his liver tumors shrunk considerably. Unfortunately, 24 months after the recurrence of HCC, he died of respiratory failure. The cause of his death was officially determined to be primary lung cancer. An autopsy revealed that most tissues were necrotic, and only a small number of viable tumor cells were present in the liver tumors. This suggests that sorafenib-HAIC sequential therapy was significantly effective in targeting the multiple HCCs in this case.

Intraductal Papillary Mucinous Neoplasm with Pancreatogastric Fistula.

We herein report a rare case of intraductal papillary mucinous neoplasm with a pancreatogastric fistula in an elderly Japanese man admitted to our hospital. The pancreatogastric fistula was confirmed using endoscopic retrograde pancreatography via a cannulated guidewire placed in the stomach. Six months after admission, the patient was diagnosed with intraductal papillary mucinous carcinoma. A pancreatogastric fistula is generally a rare complication of intraductal papillary mucinous neoplasm. It was caused by mechanical penetration in this case. Interestingly, we also observed endoscopic and histochemical mucosal changes in the fistula.

A rare case of Helicobacter pylori-uninfected intramucosal poorly differentiated adenocarcinoma that occurred in the gastric fornix.

We report a rare case of undifferentiated-type intramucosal gastric cancer that occurred in the fornix of the stomach without Helicobacter pylori infection, which consisted mainly of poorly differentiated adenocarcinoma. A 49-year-old man visited our hospital for a follow-up endoscopic examination of a small depressed lesion of the gastric fornix detected by surveillance esophagogastroduodenoscopy. On magnifying endoscopy with blue laser imaging, the depressed lesion (approximately 10 mm in diameter) was regarded as undifferentiated-type early gastric cancer that proved to be a poorly differentiated adenocarcinoma by histological examination of biopsied specimens. The cancerous lesion was successfully treated with endoscopic submucosal dissection and microscopically showed an intramucosal cancer that invaded the whole mucosal layer with predominant growth of a poorly differentiated adenocarcinoma component. The patient status was verified as Helicobacter pylori-naïve according to the strict diagnostic criteria, thereby confirming this case as an undifferentiated-type Helicobacter pylori-uninfected gastric cancer. Helicobacter pylori-uninfected intramucosal poorly differentiated adenocarcinoma occurring in the gastric fornix has not been previously reported.

[Coexistence of IgG4-related autoimmune hepatitis and inflammatory pseudotumors of the liver:a case report].

IgG4-related autoimmune hepatitis (IgG4-AIH) is characterized by hepatic inflammation and is considered an IgG4-related disease. Several inflammatory pseudotumors (IPTs) are also considered as IgG4-related diseases;however, there have been no reports of cases wherein both diseases occurred concurrently. An older adult with liver dysfunction was admitted to the hospital and was diagnosed with IgG4-AIH following a liver biopsy;IgG4-positive plasma cell infiltration in the portal tract and high serum IgG4 concentration were detected. A few months following biopsy, imaging studies revealed two IPTs in the liver. The patient was diagnosed with cryptogenic organized pneumonia several months after imaging and was treated with steroids in a different hospital. Her liver dysfunction improved, and one of the two IPTs disappeared in response to steroid treatment. The following is an account of a rare case of IgG4-AIH with IPTs of the liver.

Granulocyte Colony-stimulating Factor- and Interleukin-6-producing Large-cell Carcinoma of the Lung with Sarcomatoid Changes Suggestive of Epithelial-mesenchymal Transition: An Autopsy Case Report.

A rare case of lung cancer with the simultaneous production of granulocyte colony-stimulating factor (G-CSF) and interleukin-6 (IL-6) is reported. A 79-year-old man was admitted to our hospital due to cachectic symptoms and an increased inflammatory response. Laboratory tests and imaging studies suggested metastatic lung cancer with high serum levels of G-CSF and IL-6. He died of progressive disease, and an autopsy showed that the lung tumor had positive protein expression of both cytokines and a solid growth of large-cell carcinoma with sarcomatoid changes, possibly resulting from the epithelial-mesenchymal transition mediated by IL-6 and leading to widespread metastases.

Malignant paraganglioma of the posterior mediastinum: A case report with genetic analysis.

Paraganglioma and pheochromocytoma are rare neuroendocrine neoplasms that originate from chromaffin cells. In many of these tumors, several mutations are reported to occur in the genes of germline and/or somatic cells. A case of paraganglioma in the posterior mediastinum with highly malignant potential is reported. The patient had a rapid clinical course, and it was difficult to reach the final diagnosis. The initial diagnosis on fine-needle aspiration biopsy was a gastrointestinal stromal tumor (GIST) arising from the esophagus. Although radiation therapy was effective for the main tumor, the lung metastases did not respond sufficiently to several tyrosine kinase inhibitors. Autopsy and immunohistochemical examination using a battery of different markers resulted in a final diagnosis of malignant paraganglioma. Next-generation sequencing revealed several gene mutations and copy number variations, including of fumarate hydratase (FH), neurofibromatosis type-1 (NF1) and RET. Those gene alterations may contribute to the pathogenesis of this malignant phenotype to a certain extent. To confirm this, further cases and studies are required. In addition, it should be noted that histological examination of a small piece of tumor might have sampling bias and could cause misdiagnosis.

Oncocytic Type Intraductal Papillary Mucinous Neoplasm of the Pancreas with Unusually Low Mucin Production Mimicking Intraductal Tubulopapillary Neoplasm: A Report of a Case Diagnosed by a Preoperative Endoscopic Biopsy.

We herein report the case of a 78-year-old woman with an intraductal tumor with scant mucin production in a moderately dilated main pancreatic duct that resembled an intraductal tubulopapillary neoplasm (ITPN) on imaging. An endoscopic transpapillary forceps biopsy enabled an accurate preoperative diagnosis of the tumor as an oncocytic type intraductal papillary mucinous neoplasm (IPMN) of the pancreas microscopically showing papillary growth consisting of oncocytic cells with a typical mucin expression profile, although with few intraepithelial lumina containing mucin. This is the first case of an oncocytic type IPMN mimicking an ITPN that was able to be diagnosed preoperatively.

Anaplastic Carcinoma Possibly Arising from a Heterotopic Pancreas.

Anaplastic carcinoma is a rare pancreatic cancer, and the malignant transformation of a heterotopic pancreas is also rare. We herein report a case of an elderly woman with a mass of unknown origin in the abdominal cavity. Computed tomography identified the extent of the tumor but not the organ of origin. The abdominal tumor eventually metastasized to the liver and lung. An autopsy and immunohistochemical examination revealed an anaplastic carcinoma possibly originating in an ectopic pancreas.

Mediastinal Yolk Sac Tumor Producing Protein Induced by Vitamin K Absence or Antagonist-II.

Extragonadal yolk sac tumors (YSTs) are rare. We herein report the case of a 66-year-old man with mediastinal, lung and liver tumors. The largest mass was located in the liver and contained a high concentration of protein induced by vitamin K absence or antagonist-II (PIVKA-II) and alpha-fetoprotein. Therefore, the lesion was difficult to distinguish from hepatocellular carcinoma. Finally, YST was diagnosed based on the results of a liver biopsy. Although chemotherapy was effective, the patient died of respiratory failure. The autopsy revealed primary mediastinal YST. In the current report, we describe this case of PIVKA-II-producing YST and review previous cases of PIVKA-II-producing tumors other than hepatoma.

Hepatic portal venous gas in pancreatic solitary metastasis from an esophageal squamous cell carcinoma.

BACKGROUND: Hepatic portal venous gas (HPVG) is a rare entity commonly associated with intestinal necrosis and fatal outcome, and various underlying diseases have been reported. Pancreatic solitary metastasis without local extension is also rare in esophageal squamous cell carcinoma. METHODS: This report describes an interesting and unusual case of HPVG arising from pancreatic tumor. Autopsy revealed pathogenesis of HPVG and synchronous tumors of the esophagus and pancreas. RESULTS: A 73-year-old man developed synchronous double tumor in the esophagus and pancreas several months before acute abdomen and his death, which were generated by HPVG. Autopsy revealed that HPVG was caused by gastric wall infarction owing to expansion of an isolated pancreatic metastasis from esophageal squamous cell carcinoma. CONCLUSIONS: This is the first case of HPVG that was derived from pancreatic tumor infiltration. If he had been diagnosed with solitary pancreatic metastasis from esophageal squamous cell carcinoma in the first time, he might have an option for chemotherapy, which could let him live longer.

A case of Ménétrier's disease without Helicobacter pylori infection.

Ménétrier's disease (MD) is a rare, acquired, premalignant disorder of the stomach characterized by enlarged gastric folds with foveolar hyperplasia, the phenotype of antralization of gastric glands, hypochlorhydria and hypoproteinemia. The etiology of MD is unknown, but both increased signaling by transforming growth factor-α and infection with Helicobacter pylori (H. pylori) have been implicated. Here, a case involving 70-year-old man who lost weight after developing anorexia and diarrhea is reported. He was diagnosed as MD without H. pylori infection, and in spite of intensive care, he died 40 days after admission. An autopsy confirmed MD. Immunohistochemistry revealed overexpression of transforming growth factor-α in the foveolar region of the gastric mucosa. The autopsy also distinguished this H. pylori-negative MD from hyperplastic polyp of the stomach, which is important in clarifying the entity of H. pylori-negative MD.

Phenotypic alteration of interstitial cells of Cajal in idiopathic sigmoid megacolon.

BACKGROUND: Interstitial cells of Cajal (ICCs) are detected as a pacemaker of gastrointestinal movement and express c-kit and CD34. Recently, ICCs have implicated pathogenesis in several human diseases presenting gastrointestinal motor dysfunction. This study was performed to clarify the role of ICCs in idiopathic sigmoid megacolon using histological and immunohistochemical examinations. METHODS: Four adult patients with idiopathic sigmoid megacolon and 11 controls were studied. Histology and immunocytochemistry using NSE, S100, c-kit, and CD34 were performed in conjunction with quantitative analysis using the public domain NIH image program. RESULTS: Little histological change in neuromuscular structures in megacolon was observed. Immunohistochemistry demonstrated remarkable decrease of c-kit expressing ICCs without reduction of CD34 expression in the similar interstitial cell population. This observation was further supported by quantitative assessment using public domain NIH image program. CONCLUSIONS: A specific downregulation of c-kit in ICCs may be a cause of idiopathic sigmoid megacolon in adults.

Basaloid carcinoma of the thymus: report of a case.

We report a case of basaloid carcinoma of the thymus, confirmed by histopathological examination, in a 52-year-old man who underwent complete resection. Local recurrence and lung metastases developed, which were obliterated by radiation therapy. The patient survived for 81 months after surgery. We reviewed the 13 other cases of basaloid carcinoma of the thymus reported in the literature. Presumably, this tumor is radiosensitive and its metastatic route is blood-borne.