Published online Apr 14, 2015. doi: 10.3748/wjg.v21.i14.4391
Peer-review started: August 20, 2014
First decision: September 27, 2014
Revised: October 20, 2014
Accepted: December 16, 2014
Article in press: December 16, 2014
Published online: April 14, 2015
Processing time: 238 Days and 12.2 Hours
Myoepithelioma/myoepithelial carcinomas are not commonly found in soft tissues and are especially rare at visceral sites. This report describes a case of a rare low-grade myoepithelial carcinoma of the stomach. A 61-year-old female patient presented with postprandial abdominal discomfort. Endoscopy revealed a 1.1 cm submucosal lesion. Local excision was performed after malignancy was confirmed by biopsy. The resection margin is free of tumor and she received no adjuvant therapy. The tumor was characterized by multinodular growth with biphasic epithelioid and spindle components. Infiltrative margin and nuclear pleomorphism are seen. Tumor cells were positive for both epithelial and myoepithelial markers. Evidence of epithelial differentiation was confirmed by electron microscopy. No EWSR1 rearrangement was detected. The final diagnosis was low-grade myoepithelial gastric carcinoma. The patient is currently well, and no evidence of recurrence or metastasis was found after ten-month of follow-up. Myoepithelial carcinoma should be considered in the differential diagnosis of a biphasic gastric tumor.
Core tip: Myoepithelial tumor can cause diagnostic pitfall due to its rarity and various morphology. This report reveals a rare low-grade myoepithelial carcinoma of stomach and its morphological, immunohistochemical and molecular characteristics.