Masaomi Mizutani

Pancreatic schwannoma: Case report and an updated 30-year review of the literature yielding 47 cases

Pancreatic schwannomas are rare neoplasms. Authors briefly describe a 64-year-old female patient with cystic pancreatic schwannoma mimicking other cystic tumors and review the literature. Databases for PubMed were searched for English-language articles from 1980 to 2010 using a list of keywords, as well as references from review articles. Only 41 articles, including 47 cases, have been reported in the English literature. The mean age was 55.7 years (range 20-87 years), with 45% of patients being male. Mean tumor size was 6.2 cm (range 1-20 cm). Tumor location was the head (40%), head and body (6%), body (21%), body and tail (15%), tail (4%), and uncinate process (13%). Thirty-four percent of patients exhibited solid tumors and 60% of patients exhibited cystic tumors. Treatment included pancreaticoduodenectomy (32%), distal pancreatectomy (21%), enucleation (15%), unresectable (4%), refused operation (2%) and the detail of resection was not specified in 26% of patients. No patients died of disease with a mean follow-up of 15.7 mo (range 3-65 mo), although 5 (11%) patients had a malignancy. The tumor size was significantly related to malignant tumor (13.8 ± 6.2 cm for malignancy vs 5.5 ± 4.4 cm for benign, P = 0.001) and cystic formation (7.9 ± 5.9 cm for cystic tumor vs 3.9 ± 2.4 cm for solid tumor, P = 0.005). The preoperative diagnosis of pancreatic schwannoma remains difficult. Cystic pancreatic schwannomas should be considered in the differential diagnosis of cystic neoplasms and pseudocysts. In our case, intraoperative frozen section confirmed the diagnosis of a schwannoma. Simple enucleation may be adequate, if this is possible.

Anatomy of right recurrent nerve node: why does early metastasis of esophageal cancer occur in it?

Early, distant and/or skip metastasis of squamous-cell thoracic esophageal cancer frequently occurs in the right recurrent nerve node (recR). However, the specific lymphatic route without a nodal relay, such as the submucosal ascending route, was not known for the recR afferent. Using 20 donated cadavers, macroscopic, and histological observations were performed on the recR and its surrounding lymphatics, especially afferent routes from the esophagus to the recR. Most afferent vessels of the recR originated from the right paratracheal node. However, the recR often (12/20) received a major submucosal lymphatic drainage route ascending along the thoracic esophagus. The submucosal vessel came out of the esophagus and ran in a longitudinal connective tissue mass along the right tracheo-esophageal groove. A direct drainage route was often (13/20) seen from the recR to the venous system. Moreover, because of the specific histology, collaterals seemed to be present around the recR. In the regional nodes of the intrathoracic esophagus, the recR histology was characterized by the high proportion of lymphocyte accumulating areas or the cortex. From the midthoracic level, metastatic cancer cells seemed to reach the recR via esophageal submucosal vessels in the early stage. Large lymphocyte accumulating areas of the recR suggested higher filtration capacity than other distal nodes. However, the collateral of the recR and its direct drainage to the venous system suggested that the recR involvement often corresponds to a systemic disease.

Expression of MUC5AC and MUC6 in invasive ductal carcinoma of the pancreas and relationship with prognosis.

Aim/Background. MUC5AC and MUC6 are two major types of mucin that are abundantly present in the stomach; both of them form a gel of high viscosity that provides protection and lubrication. Expressions of MUC5AC and MUC6 are seen in pancreatic neoplasms, whereas the relationships between MUC5AC/MUC6 expression and clinicopathological factors and patient prognosis in invasive ductal carcinoma (IDC) of the pancreas have not been investigated. The aim of this study was to investigate MUC5AC and MUC6 expressions in IDC with special reference to clinicopathological factors and patient prognosis.Methods. Tissue samples were taken from 33 patients with IDC of the pancreas after radical surgical treatment. MUC5AC and MUC6 expressions were examined immunohistochemically.Results. The expressions of MUC5AC and MUC6 were observed in the cytoplasm of the tumor cells. MUC5AC and MUC6 immunoreactivities in the cancer tissues were found in 21 (63.6%) and 15 (45.5%) of 33 cases of IDC of the pancreas, respectively. MUC5AC-negative expression was associated significantly with lymphatic invasion, venous invasion, lymph node metastasis, and MUC5AC-positive patients showed significant better survival than those MUC5AC-negative patients. MUC6 expression was significantly related to tumor location, whereas MUC6 expression did not show significant relationship with patient survival.Conclusion. The results indicate that MUC5AC expression plays an important role in impacting tumor progression in IDC of the pancreas. MUC5AC expression is a benefit to better survival of patients with IDC of the pancreas. MUC6 expression is not involved in tumor progression in IDC of the pancreas.

Intrahepatic micrometastases around liver metastases from gastric cancer

BACKGROUND/PURPOSE We aimed to clarify the association between the presence of micrometastases around liver metastases from gastric cancer and the results of hepatic resection. In addition, we investigated the influence of E-cadherin and matrix metalloproteinase (MMP)-7 expression on the development of micrometastases. METHODS Micrometastases around liver metastases were examined microscopically in 31 metastatic liver tumor specimens resected from 17 patients who had undergone hepatic resection for liver metastases from gastric cancer. E-cadherin and MMP-7 expression in the primary gastric tumor, the liver metastases, and the micrometastases were examined immunohistochemically. RESULTS Hepatic micrometastases were present in around 48% of the liver metastases, accounting for 59% of the patients. The tumor recurrence rate in the remnant liver after hepatic resection was significantly higher, and survival significantly poorer, in patients with such micrometastases than in those without. Micrometastases tended to appear around the liver metastases that had reduced E-cadherin expression. Most of the micrometastases in the lymph ducts and sinusoids showed reduced E-cadherin expression. MMP-7 expression was not correlated with the presence of micrometastases. CONCLUSIONS About half of the hepatic metastases from gastric cancer had seeded off micrometastases, and the presence of these micrometastases was associated with a poorer result of hepatic resection. Reduced E-cadherin expression in metastatic liver tumors may be associated with the development of micrometastases.

Expression of MUC1 and MUC2 in Ampullary Cancer

Background. Mucins are high-molecular-weight glycoproteins that play important roles in carcinogenesis or tumor invasion. The authors investigated the expression of mucins in ampullary cancer. Methods. MUC1 and MUC2 expressions were examined using immunohistochemistry. Tissue samples were obtained from 32 patients with ampullary cancer who underwent resection at Yamagata University Hospital, Japan. The authors classified the cases with ampullary cancer into 2 subtypes—pancreatobiliary type (PB type) and intestinal type (I type)—using H&E, MUC1, and MUC2 staining. Then, the authors made a comparison of the clinicopathologic data of the 2 subtypes. Results. Fourteen patients (44%) were classified as PB type and 18 patients (56%) as I type. The PB-type group had significantly worse histopathologic characteristics than the I-type group in nodal involvement (PB type 57% vs I type 22%; P = .04), perineural invasion (PB type 50% vs I type 17%; P = .04), duodenal invasion (PB type 100% vs I type 33%; P = .01), and pancreatic invasion (PB type 71% vs I type 33%; P = .03). The PB-type group had significantly worse outcome than the I-type group (5-year survival: PB type 40% vs I type 72%; P = .03). Conclusion. PB-type ampullary cancers were more aggressive than I-type carcinomas. MUC1 and MUC2 expression was useful for classification as PB or I type.

Hyperbaric Oxygen Therapy for Pancreatic and Gastrointestinal Disease

We report the results of hyperbaric oxygen therapy (HBO) for pancreatic and gastrointestinal disease. Thirty-nine patients received 100% oxygen at 2 atmospheres absolute pressure for 60 min. Results: In all four patients with liver abscess, feverishness subsided within 2.7 days after the start of HBO. All of three patients with infection after hepatic resection were relieved of systemic inflammatory response system (SIRS) and showed reduced CRP levels after HBO. In all of seven patients with acute appendicitis, pyrexia was relieved at 1.8 days after HBO introduction, and further surgery was not necessary. Among five patients with colorectal disease, HBO was effective in four, but ineffective in one. Five of six cases of infection after pancreatic resection were cured immediately after HBO. There were no complications such as middle ear inflammation, oxygen intoxication or pneumothorax. Conclusions: HBO is sometimes effective for treatment of refractory gastro enteric infections, especially those for which drainage is difficult. Pyrexia improved within 2.3 days after the start of HBO in most cases. If infection is refractory to standard antibiotics or drainage, HBO should be considered as an additional treatment. Since HBO is safe and generally cost-effective, it should be considered as an adjunct therapy for all gastro enteric infections.

Tu1575 Conservative Treatment and Interval Appendectomy for Acute Appendicitis

BACKGROUND Conservative treatment for acute appendicitis (AA) is gradually being adopted as valuable therapeutic choice. Interval appendectomy (IA) after conservative treatment is controversial. OBJECTIVE To clarify the success and recurrence rate of conservative treatment for acute appendicitis, and necessity of IA Patients and Methods We reviewed 503 patients with AA between 2006 and 2013. RESULTS In 503 patients, of which 122 patient undergone emergency appendectomy within 3 days after admission, remaining 381 patients underwent conservative treatment. In 381 patients taken conservative treatment, the success rate of conservative treatment was 98%. Nine patients (2%) were required appendectomy because of progressive disease despite of conservative treatment. After conservative treatment 95 patients (27%) were diagnosed as a recurrent AA at median follow-up 18 months. The predictor for recurrence after conservative treatment was the only following multiple episodes of AA (p=0.002, HR 2.1, 95%CI [1.56-41.1]). The abscess formation and appendicolith did not predict the disease recurrence. At the recurrent AA, 37 of 95 (39%) patients underwent appendectomy including IA. The morbidity of appendectomy for recurrent disease was 5%. Especially the morbidity of IA for recurrent disease was 0%. CONCLUSIONS The success rate of conservative treatment was very high and the risk of recurrence after conservative treatment was 27%. The morbidity of appendectomy for recurrent disease was low (5%). The conservative treatment may be an effective alternative to emergency appendectomy. The routine IA is probably not warranted following successful management of AA, but IA should be required to patients with multiple episodes of AA. Morbidity rate of appendectomy by timing of operation