Gastric gastrointestinal stromal tumor smaller than 20 mm with liver metastasis.

There have been no reports of gastric gastrointestinal stromal tumors (GISTs) <20 mm with distant metastasis. We report a case of a 15-mm gastric GIST with liver metastasis 1 year after surgical resection of the primary lesion. A 35-year-old man underwent routine esophagogastroduodenoscopy in July 2009. A submucosal tumor (SMT) <20 mm was incidentally detected at the posterior wall of the gastric body. Endoscopic ultrasound (EUS) indicated that it was a gastrointestinal mesenchymal tumor, including GIST, leiomyoma or schwannoma. He did not accept regular follow-up for this gastric SMT, therefore local laparoscopic excision was carried out in October 2009. The final pathological diagnosis after surgery was GIST, 15 mm in size, and a mitotic rate of 7/50 high-power fields, which did not indicate a high metastatic risk. The patient was followed up regularly without adjuvant chemotherapy. At 1 year after surgery, a space-occupying lesion ~15 mm was detected in the left lobe of the liver by abdominal ultrasound, where no mass lesion had been observed before surgery. To make a definite diagnosis of the hepatic mass lesion, EUS-guided fine-needle aspiration was performed, which demonstrated a metastatic liver tumor from a gastric GIST. Although this was a rare case, we should keep in mind that gastric GISTs do have a chance of malignant behavior, even if <20 mm.

Novel magnified endoscopic findings of microvascular architecture in intramucosal gastric cancer.

BACKGROUND: The color change observed endoscopically in early gastric cancer is thought to correlate with vascular density and architecture. This study investigated the endoscopic microvascular architecture in intramucosal gastric carcinoma in vivo. METHODS: Intramucosal gastric carcinomas without ulceration in 27 patients were studied by using a new magnifying upper endoscope with attention to microvascular findings. The carcinomas were divided into two major types histologically: differentiated (18) and undifferentiated (9). RESULTS: A regular subepithelial capillary network was demonstrated in noncancerous mucosa. The appearance of the carcinomas differed depending on histologic differentiation. With all of the differentiated carcinomas, there was a well-demarcated area where the regular capillary pattern of noncancerous mucosa had disappeared and irregular microvessels were proliferating. In contrast, with undifferentiated carcinomas there was only an ill-defined area with disappearance or a reduction in the density of capillaries in the noncancerous mucosa. CONCLUSIONS: Magnified endoscopic observation of microvessels may be of assistance in the identification of intramucosal gastric carcinomas that exhibit only subtle changes in color and shape at standard endoscopy.