Endoscopic ultrasonography (EUS)-guided fine needle biopsy was useful for the diagnosis of a pancreatic gastrointestinal stromal tumor (GIST), as described in a case report published in the Journal of Gastroenterology and Hepatology.
The patient had an 11-mm hypervascularized, neoplastic lesion on the pancreatic head identified using contrast-enhanced computed tomography (CT). The lesion was observed to be a well-defined, smooth, and internally hypoechoic mass using abdominal ultrasound.
EUS also revealed the lesion to be a borderline-clear hypoechoic mass, and EUS-guided fine needle biopsy was used to collect a sample of the lesion. Rapid, on-site cytologic evaluation revealed the presence of spindle cells in the sample.
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Further testing using hematoxylin-eosin staining and immunostaining found that the spindle cells were positive for c-KIT and CD34, leading to a diagnosis of GIST.
The patient had undergone surgical resection of a duodenal submucosal GIST through pancreatic head-sparing duodenectomy 5 years prior. After surgery, the patient received treatment with imatinib for 3 years.
Retrospective analysis of preoperative CT scans revealed a 6-mm lesion in the pancreatic head that was slowly progressing, which was missed on earlier analysis. Following the EUS-guided biopsy and analysis, the GIST is under observation and being considered for resection if growth continues in the future.
The authors stated that pancreatic GISTs are very rare and can be categorized into either primary extragastrointestinal stromal tumors (EGISTs) or metastatic GISTs. They were unable to categorize this tumor because the small amount of tissue collected from the fine needle biopsy prevented testing for a KIT gene mutation.
“Although this case was a small lesion and required differentiation from a neuroendocrine tumor and other pancreatic hypervascularized tumors on clinical imaging, EUS was useful and able to accurately diagnose the GIST in the pancreas, an uncommon disease,” the authors wrote.
Hirata H, Ishiguro N, Ito K, et al. Gastrointestinal: a case of pancreatic gastrointestinal stromal tumor diagnosed by endoscopic ultrasound fine needle biopsy. J Gastroenterol Hepatol. Published online May 14, 2023. doi:10.1111/jgh.16213