title: A case of osteoclast-type giant cell tumor of the pancreas with high-frequency microsatellite instability.
abstract: It has been reported that osteoclast-type giant cell tumor of the pancreas (OGTP) is rare, with a frequency of only 0.2% of the total reported pancreatic carcinomas. We report herein a rare case of OGTP in a 57-year-old Japanese man. Preoperative examinations showed a solid and cystic tumor, measuring 20 x 15 cm at the pancreas body. The resected specimen was a solid tumor with a giant cyst containing bloody contents. The tumor was composed of a proliferation of mononuclear cells admixed with osteoclast-type giant cells. The tumor cells were immunoreactive for vimentin, alpha1-antitrypsin, and EMA but not for CEA and cytokeratin. These findings indicated that this case was a malignant OGTP. The tumor cells showed microsatellite instability with high frequency (MSI-H). The present patient is alive 3 years after the operation, while OGTP has been reported to have a poor outcome. It has been reported that pancreatic carcinomas with MSI-H status have a favorable outcome. MSI-H might be one of the predictive markers for the long survival in OGTP.
authors.affiliation: Department of Surgical Oncology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Hirohisa
authors.initials: H
authors.lastname: Osaka
authors.forename: Masakazu
authors.initials: M
authors.lastname: Yashiro
authors.forename: Hiroji
authors.initials: H
authors.lastname: Nishino
authors.forename: Bunzo
authors.initials: B
authors.lastname: Nakata
authors.forename: Masaichi
authors.initials: M
authors.lastname: Ohira
authors.forename: Kosei
authors.initials: K
authors.lastname: Hirakawa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis; D005260:Female; D042822:Genomic Instability; D005870:Giant Cell Tumors / Q000737:chemistry / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D006801:Humans; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged; D018396:Mucin-1 / Q000032:analysis; D009363:Neoplasm Proteins / Q000032:analysis; D010010:Osteoclasts / Q000737:chemistry / Q000473:pathology*; D010190:Pancreatic Neoplasms / Q000737:chemistry / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D011379:Prognosis; D012074:Remission Induction; D017154:Stromal Cells / Q000737:chemistry / Q000473:pathology; D014746:Vimentin / Q000032:analysis; D000515:alpha 1-Antitrypsin / Q000032:analysis
chemical_list: D014408:Biomarkers, Tumor; D018396:Mucin-1; D009363:Neoplasm Proteins; D014746:Vimentin; D000515:alpha 1-Antitrypsin