Specific Mutations in Exon 11 of c-kit Proto-oncogene in a malignant gastrointestinal stromal tumor of the esohagogastic junction-a case report-

초록

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal (GI) tract, most commonly in the stomach (60-70%), followed by small intestine (20-25%), colon and rectum (5%), and esophagus (<5%). They are defined as c-kit receptor-positive mesenchymal spindle or epithleioid neoplasms primary in the GI tract, omentum, and mesentery, and commonly have activating mutation in exon 11 or rarely exon 9 and exon 13 of the c-kit proto-oncogene that encodes a tyrosine kinase domain of the KIT receptor. We experienced a case of GIST occured in the esophagogastric junction with involvement of both esophagus and cardia. The patient was 44-year-old man who visited GI department due to abdominal pain. Fibergastroscopy and CT scan revealed a huge submucosal tumor of the cardia. Radical total gastrectomy specimen revealed a polypoid tumor at esophagogastric junction, measuring 12.0x10.0x7.0cm. The histology revealed a compact spindle shaped tumor cells and myxoid strom covered by squamous epithelium of esophagus in upper half and cardiac epitheliu in lower half of the tumor. Immunohistochemically, the tumor cells were diffusely positive for CD117 (c-kit) and CD34, and focally positive for desmin, smooth muscle actin, and S-100 protein. Samples separately taken from esophageal and gastric portions showed same mutation in the sequence coding the juxtamembrane domain exon 11 of the c-kit proto-oncogene revealed by a polymerase chain reaction.