Extra-gastrointestinal stromal tumor of the pancreas: case report and review of the literature

Abstract

Primary extra-gastrointestinal stromal tumor (EGISTs) arising in the pancreas is extremely rare: only 20 cases have previously been reported in the English literature from 2000 to 2013. We reported a case of EGIST of the pancreas in a 69-year-old woman who presented with abdominal pain and with a solid, heterogeneously enhancing neoplasm in the uncinate process of the pancreas, revealed preoperatively by an abdominal computed tomography scan. A diagnosis of neuroendocrine tumor was suggested. Positron emission tomography with 68Ga-DOTATOC did not show pathological accumulation of the tracer in the pancreas. The patient underwent enucleation, under ultrasonic guidance, of the pancreatic tumor that emerged to the surface of the pancreas. Histopathology and immunohistochemical examination confirmed the final diagnosis of EGIST of the pancreas (CD117+), with one mitosis per 50 high-power fields. Although rarely, GIST can involve the pancreas as a primary site, and this tumor should be considered in the differential diagnosis of pancreatic neoplasms.

Figure 1

Abdominal CT scan showing a 2-cm, contrast-enhanced mass (arrow) in the uncinate process of the pancreas.

Figure 2

Stromal tumor composed of spindle and epithelioid cells with focal vacuolar (signet ring) change. (E & E, 20×).

Figure 3

Immunostain for c-KIT: strong and diffuse cytoplasmic immunoreactivity.

Figure 4

Immunostain for CD34: focal immunoreactivity.