ABSTRACT
We describe an ovarian mucinous neoplasm that histologically resembles lobular endocervical glandular hyperplasia (LEGH) containing pyloric gland type mucin in a patient with Peutz-Jeghers syndrome (PJS). Although ovarian mucinous tumors rarely occur in PJS patients, their pyloric gland phenotype has not been clearly determined. The histopathologic features of the ovarian mucinous tumor were reminiscent of LEGH. The cytoplasmic mucin was stained with periodic acid-Schiff reaction after diastase treatment but was negative for Alcian blue pH 2.5, suggesting the presence of neutral mucin. Immunohistochemically, the epithelium expressed various gastric markers, including MUC6, HIK1083, and carbonic anhydrase-IX. Multiple ligation-dependent probe amplification detected a germline heterozygous deletion mutation at exons 1–7 of the STK11 gene (c.1-?_920+?del) in peripheral blood leukocytes and mosaic loss of heterozygosity in ovarian tumor tissue. Considering that LEGH and/or gastric-type cervical adenocarcinoma can be found in patients with PJS carrying germline and/or somatic STK11 mutations, our case indicates that STK11 mutations have an important role in the proliferation of pyloric-phenotype mucinous epithelium at various anatomical locations.
ABSTRACT
Pyloric gland adenoma is a recently described neoplasia that is very rare. It was first classified as a gastric tumor in 1990. Pyloric gland adenomas occur predominantly in old age, more frequently in women than in men, and they are often found in patients suffering from autoimmune gastritis. The diagnosis can be confirmed by immunohistochemistry, which is strongly positive for MUC6 and MUC5AC, expressed in the superficial layer. A pyloric gland adenoma is a type of gastric tumor, but it has also been reported in the gallbladder, pancreatic duct, duodenum, cervix of the uterus, rectum, and Barrett's esophagus. In 30% of gastric pyloric adenomas, transition to well-differentiated adenocarcinoma has been noted. Therefore, these lesionsshould be removed. In our case, the lesion was removed by endoscopic submucosal dissection. We report a case of pyloric gland adenoma in the cardia of the stomach showing typical endoscopic and microscopic features. This is the first case of pyloric gland adenoma of the stomach reported in Korea.