Gastric Invasive Micropapillary Carcinoma with Intestinal Phenotypes Harboring a TP53 R175H Mutation.

We report a case of gastric invasive micropapillary carcinoma (IMPC) in an 86-year-old female patient. She was admitted to our hospital with a chief complaint of bloody emesis. Upper gastrointestinal endoscopy found a gastric adenocarcinoma at the antrum. The biopsy specimens showed moderately differentiated adenocarcinoma with invasive small tumor nests. Distal gastrectomy with systematic lymph node dissection demonstrated that the tumor had IMPC through a pathological examination. Despite the depth of tumor invasion (the submucosa), extensive lymph node metastases were observed. Anti-D2-40 immunostaining revealed numerous infiltrating tumor cell nests in the lymphatic vessels, which could explain subsequent multiple lymph node metastases. The adenocarcinoma showed intestinal phenotypes by several immunohistochemical studies. One of these antibodies (CD10) clearly demonstrated the inverted apical-basal (inside-out) pattern of IMPC, whereas it showed an ordinary pattern in intestinal metaplasia adjacent to the tumor. Furthermore, genetic analysis by direct sequencing revealed a point mutation in the exon 5 of TP53 in the tumor. The mutation presumably harbors a missense mutation from Arg to His at the codon 175 (R175H). R175H has been previously described as a 'gain-of-function' mutation with a high invasive or metastatic potential in several types of cancers. In summary, this is one of the first reported cases of gastric IMPC with intestinal phenotypes harboring a TP53 R175H mutation in the literature.

Mucinous cystic tumors of the pancreas.

PURPOSE: This study was conducted to clarify the clinicopathologic characteristics relevant to the specific diagnosis of mucinous cystic tumors of the pancreas. METHODS: We retrospectively reviewed the clinical features and histopathologic findings of five patients who underwent curative resection for mucinous cystic tumors of the pancreas at our hospital between 1975 and 2000. RESULTS: All five patients were women, ranging in age from 36 to 69 years, and the tumors were located in the pancreatic body and tail. Histopathologically, three tumors were mucinous cystadenomas and two were mucinous cystadenocarcinomas. All five tumors had ovarian-type stroma, and stromal luteinization was found in the three adenomas. These tumors were classified into two groups according to whether the epithelial lining was endocervical or intestinal. All tumors were spherical and multilocular with a fibrous pseudocapsule. On T1-weighted magnetic resonance images, mucinous cystadenomas with watery mucin showed low signal intensity, but mucinous cystadenocarcinomas with gelatinous mucin or hemorrhagic contents demonstrated high signal intensity. CONCLUSIONS: Signal intensity on T1-weighted magnetic resonance images provides highly useful diagnostic information on mucinous cystic tumors of the pancreas. Furthermore, tumors may be classified into two groups according to the type of epithelial lining.