Small bud of probable gastrointestinal stromal tumor within a laparoscopically-resected gastric schwannoma

• Published in: International journal of clinical oncology Vol. 17; no. 3; pp. 294 - 298
• Main Authors: Cho, Haruhiko, Watanabe, Takafumi, Aoyama, Toru, Hayashi, Tsutomu, Yamada, Takanobu, Ogata, Takashi, Yoshikawa, Takaki, Tsuburaya, Akira, Sekiguchi, Hironobu, Nakamura, Yoshiyasu, Sakuma, Yuji, Kameda, Yoichi, Miyagi, Yohei
• Format: Journal Article
• Language: English
• Published: Japan Springer Japan 01-06-2012; Springer Nature B.V
• Subjects: Cancer Research; Case Report; Gastrointestinal diseases; Gastrointestinal Neoplasms - pathology; Gastrointestinal Stromal Tumors - pathology; Genotype; Genotype & phenotype; Humans; Medical diagnosis; Medicine; Medicine & Public Health; Middle Aged; Mutation; Neoplasms, Complex and Mixed - pathology; Neurilemmoma - pathology; Oncology; Proto-Oncogene Proteins c-kit - genetics; Proto-Oncogene Proteins c-kit - metabolism; Surgical Oncology; Tumors; Gastric schwannoma; Gastrointestinal stromal tumor
• ISSN: 1341-9625; 1437-7772
• DOI: 10.1007/s10147-011-0296-1

Submucosal tumors (SMTs) of the gastrointestinal (GI) tract can be potentially difficulty to diagnose pathologically. We report a case of a gastric SMT that was resected by laparoscopic partial gastrectomy. Although the initial histological and immunohistochemical examinations considered the tumor as a schwannoma, mRNA-based
KIT
genotyping indicated that the tumor included cells with
KIT
gene expression, and that a small number of cells carried a deletion mutation in exon 11. Additional histopathological investigations revealed small aggregates of enlarged spindle to epithelioid cells, which were positive for KIT, CD34 and DOG1, and negative for S-100, scattered among the S-100-positive schwannoma cells. We consider that the cells carrying the
KIT
gene mutation are microscopic buds of a gastrointestinal stroma tumor (GIST), and to the best of our knowledge, this is the first report of probable GIST tissues identified in a schwannoma. Our observations raised the significance of genotyping for diagnosis of GI tract SMTs.