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From the Archives of the AFIP

Gastrointestinal Stromal Tumors: Radiologic Features with Pathologic Correlation¹

¹ From the Departments of Radiologic Pathology (A.D.L., W.M.T.), Hepatic and Gastrointestinal Pathology (H.E.R., L.H.S.), and Soft Tissue Pathology (M.M.), Armed Forces Institute of Pathology, 6825 16th St NW, Washington, DC 20306-6000; Department of Radiology and Nuclear Medicine, Uniformed Services University of the Health Sciences, Bethesda, Md (A.D.L.); and Department of Radiology, Duke University, Durham, NC (W.M.T.). Received August 30, 2002; revision requested October 3 and received October 11; accepted October 16. Address correspondence to A.D.L. (levya@afip.osd.mil).

View larger version (126K): [in a new window]   Figure 1a.  Gross pathologic features of GISTs. (a) Photomicrograph (actual size [1:]; hematoxylin-eosin [H-E] stain) of resected jejunum from an 82-year-old man with gastrointestinal bleeding shows an intramural GIST with its origin in the muscularis propria (solid arrows). There is intact overlying normal small intestinal mucosa (open arrow). (b) Intraoperative photograph of the serosal surface of the ileum in a 70-year-old man who presented with melena shows a 6.0-cm pedunculated GIST. (c) Photograph of resected and opened jejunum from a 67-year-old man who presented with melena shows a 4.0-cm hemorrhagic GIST protruding into the intestinal lumen. The mucosa overlying the tumor is ulcerated (arrow). (d) Photograph of a bivalved resected 18-cm GIST from the ileum of a 66-year-old man who presented with weight loss shows a central cavity containing hemorrhage.

View larger version (126K): [in a new window]   Figure 1b.  Gross pathologic features of GISTs. (a) Photomicrograph (actual size [1:]; hematoxylin-eosin [H-E] stain) of resected jejunum from an 82-year-old man with gastrointestinal bleeding shows an intramural GIST with its origin in the muscularis propria (solid arrows). There is intact overlying normal small intestinal mucosa (open arrow). (b) Intraoperative photograph of the serosal surface of the ileum in a 70-year-old man who presented with melena shows a 6.0-cm pedunculated GIST. (c) Photograph of resected and opened jejunum from a 67-year-old man who presented with melena shows a 4.0-cm hemorrhagic GIST protruding into the intestinal lumen. The mucosa overlying the tumor is ulcerated (arrow). (d) Photograph of a bivalved resected 18-cm GIST from the ileum of a 66-year-old man who presented with weight loss shows a central cavity containing hemorrhage.

View larger version (154K): [in a new window]   Figure 1c.  Gross pathologic features of GISTs. (a) Photomicrograph (actual size [1:]; hematoxylin-eosin [H-E] stain) of resected jejunum from an 82-year-old man with gastrointestinal bleeding shows an intramural GIST with its origin in the muscularis propria (solid arrows). There is intact overlying normal small intestinal mucosa (open arrow). (b) Intraoperative photograph of the serosal surface of the ileum in a 70-year-old man who presented with melena shows a 6.0-cm pedunculated GIST. (c) Photograph of resected and opened jejunum from a 67-year-old man who presented with melena shows a 4.0-cm hemorrhagic GIST protruding into the intestinal lumen. The mucosa overlying the tumor is ulcerated (arrow). (d) Photograph of a bivalved resected 18-cm GIST from the ileum of a 66-year-old man who presented with weight loss shows a central cavity containing hemorrhage.

View larger version (127K): [in a new window]   Figure 1d.  Gross pathologic features of GISTs. (a) Photomicrograph (actual size [1:]; hematoxylin-eosin [H-E] stain) of resected jejunum from an 82-year-old man with gastrointestinal bleeding shows an intramural GIST with its origin in the muscularis propria (solid arrows). There is intact overlying normal small intestinal mucosa (open arrow). (b) Intraoperative photograph of the serosal surface of the ileum in a 70-year-old man who presented with melena shows a 6.0-cm pedunculated GIST. (c) Photograph of resected and opened jejunum from a 67-year-old man who presented with melena shows a 4.0-cm hemorrhagic GIST protruding into the intestinal lumen. The mucosa overlying the tumor is ulcerated (arrow). (d) Photograph of a bivalved resected 18-cm GIST from the ileum of a 66-year-old man who presented with weight loss shows a central cavity containing hemorrhage.

View larger version (195K): [in a new window]   Figure 2a.  Cytologic features of GISTs. (a) Photomicrograph (original magnification, x40; H-E stain) of a spindle cell GIST shows uniform cigar-shaped cells with elongated nuclei. (b) Photomicrograph (original magnification, x40; H-E stain) of an epithelioid GIST shows round cells with centrally placed nuclei. (c) Photomicrograph (original magnification, x40; H-E stain) shows the signet ring appearance from prominent cytoplasmic vacuolization in a GIST.

View larger version (200K): [in a new window]   Figure 2b.  Cytologic features of GISTs. (a) Photomicrograph (original magnification, x40; H-E stain) of a spindle cell GIST shows uniform cigar-shaped cells with elongated nuclei. (b) Photomicrograph (original magnification, x40; H-E stain) of an epithelioid GIST shows round cells with centrally placed nuclei. (c) Photomicrograph (original magnification, x40; H-E stain) shows the signet ring appearance from prominent cytoplasmic vacuolization in a GIST.

View larger version (191K): [in a new window]   Figure 2c.  Cytologic features of GISTs. (a) Photomicrograph (original magnification, x40; H-E stain) of a spindle cell GIST shows uniform cigar-shaped cells with elongated nuclei. (b) Photomicrograph (original magnification, x40; H-E stain) of an epithelioid GIST shows round cells with centrally placed nuclei. (c) Photomicrograph (original magnification, x40; H-E stain) shows the signet ring appearance from prominent cytoplasmic vacuolization in a GIST.

View larger version (226K): [in a new window]   Figure 3a.  Architectural patterns of GISTs. (a) Photomicrograph (original magnification, x10; H-E stain) of a spindle cell GIST shows a pattern of interlacing fascicles. (b) Photomicrograph (original magnification, x10; H-E stain) of a spindle cell GIST shows a nuclear palisading pattern. (c) Photomicrograph (original magnification, x10; H-E stain) of a spindle cell GIST shows an angiomatoid pattern with large blood-filled vascular spaces within the tumor.

View larger version (195K): [in a new window]   Figure 3b.  Architectural patterns of GISTs. (a) Photomicrograph (original magnification, x10; H-E stain) of a spindle cell GIST shows a pattern of interlacing fascicles. (b) Photomicrograph (original magnification, x10; H-E stain) of a spindle cell GIST shows a nuclear palisading pattern. (c) Photomicrograph (original magnification, x10; H-E stain) of a spindle cell GIST shows an angiomatoid pattern with large blood-filled vascular spaces within the tumor.

View larger version (195K): [in a new window]   Figure 3c.  Architectural patterns of GISTs. (a) Photomicrograph (original magnification, x10; H-E stain) of a spindle cell GIST shows a pattern of interlacing fascicles. (b) Photomicrograph (original magnification, x10; H-E stain) of a spindle cell GIST shows a nuclear palisading pattern. (c) Photomicrograph (original magnification, x10; H-E stain) of a spindle cell GIST shows an angiomatoid pattern with large blood-filled vascular spaces within the tumor.

View larger version (207K): [in a new window]   Figure 4a.  Stromal features of GISTs. (a) Photomicrograph (original magnification, x10; H-E stain) shows a GIST that has extensive myxoid stroma with interspersed tumor cells. (b) Photomicrograph (original magnification, x10; H-E stain) of a spindle cell GIST shows perivascular hyalinization.

View larger version (208K): [in a new window]   Figure 4b.  Stromal features of GISTs. (a) Photomicrograph (original magnification, x10; H-E stain) shows a GIST that has extensive myxoid stroma with interspersed tumor cells. (b) Photomicrograph (original magnification, x10; H-E stain) of a spindle cell GIST shows perivascular hyalinization.

View larger version (179K): [in a new window]   Figure 5.  Photomicrograph of a small intestinal GIST (original magnification, x80; H-E stain) shows eosinophilic skeinoid fibers (arrow).

View larger version (200K): [in a new window]   Figure 6a.  Cytologic features as a reflection of biologic potential. (a) Photomicrograph (original magnification, x40; H-E stain) of a low-risk or probably benign GIST shows bland-appearing tumor cells and absent mitotic activity. (b) Photomicrograph (original magnification, x40; H-E stain) of an intermediate-risk or low-grade malignant GIST shows a more cellular tumor with higher nuclear-cytoplasmic ratio. (c) Photomicrograph (original magnification, x40; H-E stain) of a high-risk or highly malignant GIST shows increased cellularity, high nuclear-cytoplasmic ratio, and numerous mitoses (arrows).

View larger version (209K): [in a new window]   Figure 6b.  Cytologic features as a reflection of biologic potential. (a) Photomicrograph (original magnification, x40; H-E stain) of a low-risk or probably benign GIST shows bland-appearing tumor cells and absent mitotic activity. (b) Photomicrograph (original magnification, x40; H-E stain) of an intermediate-risk or low-grade malignant GIST shows a more cellular tumor with higher nuclear-cytoplasmic ratio. (c) Photomicrograph (original magnification, x40; H-E stain) of a high-risk or highly malignant GIST shows increased cellularity, high nuclear-cytoplasmic ratio, and numerous mitoses (arrows).

View larger version (224K): [in a new window]   Figure 6c.  Cytologic features as a reflection of biologic potential. (a) Photomicrograph (original magnification, x40; H-E stain) of a low-risk or probably benign GIST shows bland-appearing tumor cells and absent mitotic activity. (b) Photomicrograph (original magnification, x40; H-E stain) of an intermediate-risk or low-grade malignant GIST shows a more cellular tumor with higher nuclear-cytoplasmic ratio. (c) Photomicrograph (original magnification, x40; H-E stain) of a high-risk or highly malignant GIST shows increased cellularity, high nuclear-cytoplasmic ratio, and numerous mitoses (arrows).

View larger version (188K): [in a new window]   Figure 7.  KIT immunoreactivity. Photomicrograph (original magnification, x20; KIT [CD117] stain) of a GIST shows that the cytoplasm of the tumor cells stains brown, indicating immunoreactivity.

View larger version (109K): [in a new window]   Figure 8a.  GIST arising from the stomach in a 66-year-old woman with left-sided upper abdominal pain. (a) Chest radiograph shows elevation of the left hemidiaphragm and a mass of soft-tissue opacity that displaces an irregular gas collection away from the diaphragm (arrow). (b, c) Contrast material-enhanced CT scans (c obtained at a lower level than b) show the subdiaphragmatic cavitary mass of heterogeneous attenuation. The cavity (*) is air-filled. The mass originates from the gastric wall (arrow). There is a metastatic lesion within the liver.

View larger version (123K): [in a new window]   Figure 8b.  GIST arising from the stomach in a 66-year-old woman with left-sided upper abdominal pain. (a) Chest radiograph shows elevation of the left hemidiaphragm and a mass of soft-tissue opacity that displaces an irregular gas collection away from the diaphragm (arrow). (b, c) Contrast material-enhanced CT scans (c obtained at a lower level than b) show the subdiaphragmatic cavitary mass of heterogeneous attenuation. The cavity (*) is air-filled. The mass originates from the gastric wall (arrow). There is a metastatic lesion within the liver.

View larger version (127K): [in a new window]   Figure 8c.  GIST arising from the stomach in a 66-year-old woman with left-sided upper abdominal pain. (a) Chest radiograph shows elevation of the left hemidiaphragm and a mass of soft-tissue opacity that displaces an irregular gas collection away from the diaphragm (arrow). (b, c) Contrast material-enhanced CT scans (c obtained at a lower level than b) show the subdiaphragmatic cavitary mass of heterogeneous attenuation. The cavity (*) is air-filled. The mass originates from the gastric wall (arrow). There is a metastatic lesion within the liver.

View larger version (165K): [in a new window]   Figure 9a.  Features of GISTs seen during upper gastrointestinal tract series. (a) Anteroposterior view of the stomach from a barium study in a 67-year-old man shows a smoothly circumscribed mass in the body of the stomach viewed en face (arrows). (b) Oblique view of the stomach from a barium study in a 67-year-old woman shows a smoothly marginated, mural-based mass that forms obtuse angles with the gastric wall.

View larger version (149K): [in a new window]   Figure 9b.  Features of GISTs seen during upper gastrointestinal tract series. (a) Anteroposterior view of the stomach from a barium study in a 67-year-old man shows a smoothly circumscribed mass in the body of the stomach viewed en face (arrows). (b) Oblique view of the stomach from a barium study in a 67-year-old woman shows a smoothly marginated, mural-based mass that forms obtuse angles with the gastric wall.

View larger version (117K): [in a new window]   Figure 10a.  GIST arising from the stomach in a 65-year-old man with left-sided upper abdominal pain. (a) Contrast-enhanced CT scan shows a large mass arising from the posterior gastric wall (arrow) that extends into the gastrosplenic ligament. There are areas of low attenuation within the mass. (b) Photograph of the cut surface of the resected specimen shows areas of hemorrhage and necrosis within the tumor.

View larger version (135K): [in a new window]   Figure 10b.  GIST arising from the stomach in a 65-year-old man with left-sided upper abdominal pain. (a) Contrast-enhanced CT scan shows a large mass arising from the posterior gastric wall (arrow) that extends into the gastrosplenic ligament. There are areas of low attenuation within the mass. (b) Photograph of the cut surface of the resected specimen shows areas of hemorrhage and necrosis within the tumor.

View larger version (135K): [in a new window]   Figure 11a.  GIST arising from the lesser curvature of the stomach in a 55-year-old man with melena and hematemesis. (a, b) Contrast-enhanced CT scans (b obtained at a lower level than a) show a cavitary mass that extends into the gastrohepatic and gastrosplenic ligaments. The cavity contains air (solid straight arrow) and oral contrast material (curved arrow). Low-attenuation areas in the tumor (open arrow) represent hemorrhage. (c) Photograph of the bivalved resected specimen shows a cavity (*) and areas of hemorrhage (arrow) in the solid portions of the tumor.

View larger version (135K): [in a new window]   Figure 11b.  GIST arising from the lesser curvature of the stomach in a 55-year-old man with melena and hematemesis. (a, b) Contrast-enhanced CT scans (b obtained at a lower level than a) show a cavitary mass that extends into the gastrohepatic and gastrosplenic ligaments. The cavity contains air (solid straight arrow) and oral contrast material (curved arrow). Low-attenuation areas in the tumor (open arrow) represent hemorrhage. (c) Photograph of the bivalved resected specimen shows a cavity (*) and areas of hemorrhage (arrow) in the solid portions of the tumor.

View larger version (114K): [in a new window]   Figure 11c.  GIST arising from the lesser curvature of the stomach in a 55-year-old man with melena and hematemesis. (a, b) Contrast-enhanced CT scans (b obtained at a lower level than a) show a cavitary mass that extends into the gastrohepatic and gastrosplenic ligaments. The cavity contains air (solid straight arrow) and oral contrast material (curved arrow). Low-attenuation areas in the tumor (open arrow) represent hemorrhage. (c) Photograph of the bivalved resected specimen shows a cavity (*) and areas of hemorrhage (arrow) in the solid portions of the tumor.

View larger version (138K): [in a new window]   Figure 12a.  GIST arising from the posterior stomach in a 72-year-old woman with back pain. Contrast-enhanced CT scans (b obtained at a lower level than a) show a soft-tissue attenuation mass arising from the posterior wall of the stomach (straight arrow). The mass extends into the gastrosplenic ligament and contains extensive dense calcification (curved arrow).

View larger version (139K): [in a new window]   Figure 12b.  GIST arising from the posterior stomach in a 72-year-old woman with back pain. Contrast-enhanced CT scans (b obtained at a lower level than a) show a soft-tissue attenuation mass arising from the posterior wall of the stomach (straight arrow). The mass extends into the gastrosplenic ligament and contains extensive dense calcification (curved arrow).

View larger version (110K): [in a new window]   Figure 13a.  Gastric GIST in a 66-year-old woman with left-sided upper abdominal pain. (a) Axial T1-weighted MR image shows a subdiaphragmatic hypointense mass containing a cavity (*) in the left side of the upper abdomen. (b) On the T2-weighted image, the mass increases in signal intensity. Areas of focal high-signal-intensity hemorrhage are present within the mass (arrow). (c) Coronal T2-weighted image shows that the mass originates from the gastric fundus (arrow).

View larger version (120K): [in a new window]   Figure 13b.  Gastric GIST in a 66-year-old woman with left-sided upper abdominal pain. (a) Axial T1-weighted MR image shows a subdiaphragmatic hypointense mass containing a cavity (*) in the left side of the upper abdomen. (b) On the T2-weighted image, the mass increases in signal intensity. Areas of focal high-signal-intensity hemorrhage are present within the mass (arrow). (c) Coronal T2-weighted image shows that the mass originates from the gastric fundus (arrow).

View larger version (128K): [in a new window]   Figure 13c.  Gastric GIST in a 66-year-old woman with left-sided upper abdominal pain. (a) Axial T1-weighted MR image shows a subdiaphragmatic hypointense mass containing a cavity (*) in the left side of the upper abdomen. (b) On the T2-weighted image, the mass increases in signal intensity. Areas of focal high-signal-intensity hemorrhage are present within the mass (arrow). (c) Coronal T2-weighted image shows that the mass originates from the gastric fundus (arrow).

View larger version (144K): [in a new window]   Figure 14a.  Gastric schwannoma in a 69-year-old woman with postprandial epigastric pain. (a) Image from an upper gastrointestinal tract series shows a mural-based mass along the lesser curvature of the stomach (arrows). (b) Contrast-enhanced CT scan shows the homogeneous low-attenuation gastric mass (S) extending into the gastrohepatic ligament. (c) Photograph of the cut surface of the resected specimen shows a yellow tumor in the gastric wall with no evidence of hemorrhage or necrosis. Scale is in centimeters. (d) Photomicrograph (original magnification, x2; H-E stain) shows the tumor, which is composed of spindle-shaped cells arising from the muscularis propria. There is a peripheral lymphoid cuff (arrows) within the tumor.

View larger version (132K): [in a new window]   Figure 14b.  Gastric schwannoma in a 69-year-old woman with postprandial epigastric pain. (a) Image from an upper gastrointestinal tract series shows a mural-based mass along the lesser curvature of the stomach (arrows). (b) Contrast-enhanced CT scan shows the homogeneous low-attenuation gastric mass (S) extending into the gastrohepatic ligament. (c) Photograph of the cut surface of the resected specimen shows a yellow tumor in the gastric wall with no evidence of hemorrhage or necrosis. Scale is in centimeters. (d) Photomicrograph (original magnification, x2; H-E stain) shows the tumor, which is composed of spindle-shaped cells arising from the muscularis propria. There is a peripheral lymphoid cuff (arrows) within the tumor.

View larger version (154K): [in a new window]   Figure 14c.  Gastric schwannoma in a 69-year-old woman with postprandial epigastric pain. (a) Image from an upper gastrointestinal tract series shows a mural-based mass along the lesser curvature of the stomach (arrows). (b) Contrast-enhanced CT scan shows the homogeneous low-attenuation gastric mass (S) extending into the gastrohepatic ligament. (c) Photograph of the cut surface of the resected specimen shows a yellow tumor in the gastric wall with no evidence of hemorrhage or necrosis. Scale is in centimeters. (d) Photomicrograph (original magnification, x2; H-E stain) shows the tumor, which is composed of spindle-shaped cells arising from the muscularis propria. There is a peripheral lymphoid cuff (arrows) within the tumor.

View larger version (164K): [in a new window]   Figure 14d.  Gastric schwannoma in a 69-year-old woman with postprandial epigastric pain. (a) Image from an upper gastrointestinal tract series shows a mural-based mass along the lesser curvature of the stomach (arrows). (b) Contrast-enhanced CT scan shows the homogeneous low-attenuation gastric mass (S) extending into the gastrohepatic ligament. (c) Photograph of the cut surface of the resected specimen shows a yellow tumor in the gastric wall with no evidence of hemorrhage or necrosis. Scale is in centimeters. (d) Photomicrograph (original magnification, x2; H-E stain) shows the tumor, which is composed of spindle-shaped cells arising from the muscularis propria. There is a peripheral lymphoid cuff (arrows) within the tumor.

View larger version (124K): [in a new window]   Figure 15a.  Small intestinal GIST in a 93-year-old woman with acute abdominal pain. (a) Abdominal radiograph shows a small bowel obstruction and a mass of soft-tissue opacity in the right lower quadrant. Intestinal gas is absent. (b) Unenhanced CT scan shows dilated segments of small intestine and the well-circumscribed, low-attenuation mass in the right side of the pelvis. (c) Intraoperative photograph shows the 20-cm mass arising from the jejunum that had undergone torsion, which resulted in small bowel obstruction.

View larger version (118K): [in a new window]   Figure 15b.  Small intestinal GIST in a 93-year-old woman with acute abdominal pain. (a) Abdominal radiograph shows a small bowel obstruction and a mass of soft-tissue opacity in the right lower quadrant. Intestinal gas is absent. (b) Unenhanced CT scan shows dilated segments of small intestine and the well-circumscribed, low-attenuation mass in the right side of the pelvis. (c) Intraoperative photograph shows the 20-cm mass arising from the jejunum that had undergone torsion, which resulted in small bowel obstruction.

View larger version (101K): [in a new window]   Figure 15c.  Small intestinal GIST in a 93-year-old woman with acute abdominal pain. (a) Abdominal radiograph shows a small bowel obstruction and a mass of soft-tissue opacity in the right lower quadrant. Intestinal gas is absent. (b) Unenhanced CT scan shows dilated segments of small intestine and the well-circumscribed, low-attenuation mass in the right side of the pelvis. (c) Intraoperative photograph shows the 20-cm mass arising from the jejunum that had undergone torsion, which resulted in small bowel obstruction.

View larger version (125K): [in a new window]   Figure 16.  Small intestinal GIST in a 54-year-old woman with a palpable abdominal mass. Abdominal radiograph obtained with the patient supine shows a soft-tissue mass in the left side of the midabdomen. The mass contains an irregular collection of air (arrows).

View larger version (141K): [in a new window]   Figure 17a.  Small intestinal GIST in a 28-year-old man who presented with melena. (a) Image from an enteroclysis study shows a smoothly circumscribed, 3-cm mural mass with central ulceration in the proximal jejunum (arrow). (b) Photograph from enteroscopy shows the ulcerated mass in the proximal jejunum (arrows).

View larger version (125K): [in a new window]   Figure 17b.  Small intestinal GIST in a 28-year-old man who presented with melena. (a) Image from an enteroclysis study shows a smoothly circumscribed, 3-cm mural mass with central ulceration in the proximal jejunum (arrow). (b) Photograph from enteroscopy shows the ulcerated mass in the proximal jejunum (arrows).

View larger version (133K): [in a new window]   Figure 18a.  Small intestinal GIST in a 56-year-old man who presented with fatigue, weight loss, and melena. (a) Image from a barium study of the small intestine shows barium extending from the intestinal lumen into a cavity (arrows). There is mass effect on adjacent segments of small intestine. (b) Contrast-enhanced CT scan shows a cavitary mass in the pelvis that contains air and oral contrast material (arrows).

View larger version (138K): [in a new window]   Figure 18b.  Small intestinal GIST in a 56-year-old man who presented with fatigue, weight loss, and melena. (a) Image from a barium study of the small intestine shows barium extending from the intestinal lumen into a cavity (arrows). There is mass effect on adjacent segments of small intestine. (b) Contrast-enhanced CT scan shows a cavitary mass in the pelvis that contains air and oral contrast material (arrows).

View larger version (124K): [in a new window]   Figure 19a.  CT features of small intestinal GISTs. (a) Unenhanced CT scan of a 77-year-old man shows an intraluminal polypoid small intestinal mass (arrow) that was incidentally discovered when he was being evaluated for an abdominal aortic aneurysm. (b) Contrast-enhanced CT scan of a 62-year-old woman with melena shows a heterogeneously enhancing mass in the posterior pelvis (arrow) that is arising from the distal ileum. (c) Contrast-enhanced CT scan of a 67-year-old man who presented with melena and a history of gastrointestinal bleeding shows a soft-tissue attenuation mass in the distal jejunum. The mass has an intraluminal component (arrow) and an extraluminal component, which invades an adjacent segment of small intestine. (d) Contrast-enhanced CT scan of a 66-year-old man with abdominal pain shows a cavitary mass in the right side of the midabdomen that contains air, debris, and oral contrast material.

View larger version (125K): [in a new window]   Figure 19b.  CT features of small intestinal GISTs. (a) Unenhanced CT scan of a 77-year-old man shows an intraluminal polypoid small intestinal mass (arrow) that was incidentally discovered when he was being evaluated for an abdominal aortic aneurysm. (b) Contrast-enhanced CT scan of a 62-year-old woman with melena shows a heterogeneously enhancing mass in the posterior pelvis (arrow) that is arising from the distal ileum. (c) Contrast-enhanced CT scan of a 67-year-old man who presented with melena and a history of gastrointestinal bleeding shows a soft-tissue attenuation mass in the distal jejunum. The mass has an intraluminal component (arrow) and an extraluminal component, which invades an adjacent segment of small intestine. (d) Contrast-enhanced CT scan of a 66-year-old man with abdominal pain shows a cavitary mass in the right side of the midabdomen that contains air, debris, and oral contrast material.

View larger version (111K): [in a new window]   Figure 19c.  CT features of small intestinal GISTs. (a) Unenhanced CT scan of a 77-year-old man shows an intraluminal polypoid small intestinal mass (arrow) that was incidentally discovered when he was being evaluated for an abdominal aortic aneurysm. (b) Contrast-enhanced CT scan of a 62-year-old woman with melena shows a heterogeneously enhancing mass in the posterior pelvis (arrow) that is arising from the distal ileum. (c) Contrast-enhanced CT scan of a 67-year-old man who presented with melena and a history of gastrointestinal bleeding shows a soft-tissue attenuation mass in the distal jejunum. The mass has an intraluminal component (arrow) and an extraluminal component, which invades an adjacent segment of small intestine. (d) Contrast-enhanced CT scan of a 66-year-old man with abdominal pain shows a cavitary mass in the right side of the midabdomen that contains air, debris, and oral contrast material.

View larger version (123K): [in a new window]   Figure 19d.  CT features of small intestinal GISTs. (a) Unenhanced CT scan of a 77-year-old man shows an intraluminal polypoid small intestinal mass (arrow) that was incidentally discovered when he was being evaluated for an abdominal aortic aneurysm. (b) Contrast-enhanced CT scan of a 62-year-old woman with melena shows a heterogeneously enhancing mass in the posterior pelvis (arrow) that is arising from the distal ileum. (c) Contrast-enhanced CT scan of a 67-year-old man who presented with melena and a history of gastrointestinal bleeding shows a soft-tissue attenuation mass in the distal jejunum. The mass has an intraluminal component (arrow) and an extraluminal component, which invades an adjacent segment of small intestine. (d) Contrast-enhanced CT scan of a 66-year-old man with abdominal pain shows a cavitary mass in the right side of the midabdomen that contains air, debris, and oral contrast material.

View larger version (114K): [in a new window]   Figure 20a.  Rectal GIST in a 69-year-old woman with pelvic pain and hematochezia. (a) CT scan shows a mural mass along the left anterolateral rectal wall (arrow). (b) Photograph of the opened abdominoperineal resected specimen and bivalved GIST shows the tumor in the distal rectum. Multiple foci of hemorrhage are present within the tumor.

View larger version (126K): [in a new window]   Figure 20b.  Rectal GIST in a 69-year-old woman with pelvic pain and hematochezia. (a) CT scan shows a mural mass along the left anterolateral rectal wall (arrow). (b) Photograph of the opened abdominoperineal resected specimen and bivalved GIST shows the tumor in the distal rectum. Multiple foci of hemorrhage are present within the tumor.

View larger version (134K): [in a new window]   Figure 21.  Rectal GIST in a 55-year-old man with rectal pain. CT scan shows a 5-cm mass (arrows) arising from the posterior rectal wall and extending into the ischiorectal fossa.

View larger version (120K): [in a new window]   Figure 22a.  Colonic GIST in a 47-year-old woman with a small bowel obstruction. (a) CT scan shows a lobulated 10-cm mass obstructing the ascending colon (arrow). The mass shows heterogeneous enhancement with intravenous contrast material. There are dilated, fluid-filled segments of small intestine, and a small amount of fluid is in the adjacent right paracolic gutter. (b) Photograph of the right hemicolectomy specimen shows the GIST at the level of the hepatic flexure (arrows). C = cecum, TI = terminal ileum.

View larger version (125K): [in a new window]   Figure 22b.  Colonic GIST in a 47-year-old woman with a small bowel obstruction. (a) CT scan shows a lobulated 10-cm mass obstructing the ascending colon (arrow). The mass shows heterogeneous enhancement with intravenous contrast material. There are dilated, fluid-filled segments of small intestine, and a small amount of fluid is in the adjacent right paracolic gutter. (b) Photograph of the right hemicolectomy specimen shows the GIST at the level of the hepatic flexure (arrows). C = cecum, TI = terminal ileum.

View larger version (85K): [in a new window]   Figure 23a.  Esophageal GIST in a 71-year-old man who presented with upper gastrointestinal tract bleeding. (a) Lateral chest radiograph shows a retrocardiac mass. (b) Barium esophagram shows the distal esophageal mass that distorts and widens the esophageal lumen. (c) Unenhanced CT scan shows a 16-cm soft-tissue attenuation mass involving the esophagus.

View larger version (51K): [in a new window]   Figure 23b.  Esophageal GIST in a 71-year-old man who presented with upper gastrointestinal tract bleeding. (a) Lateral chest radiograph shows a retrocardiac mass. (b) Barium esophagram shows the distal esophageal mass that distorts and widens the esophageal lumen. (c) Unenhanced CT scan shows a 16-cm soft-tissue attenuation mass involving the esophagus.

View larger version (151K): [in a new window]   Figure 23c.  Esophageal GIST in a 71-year-old man who presented with upper gastrointestinal tract bleeding. (a) Lateral chest radiograph shows a retrocardiac mass. (b) Barium esophagram shows the distal esophageal mass that distorts and widens the esophageal lumen. (c) Unenhanced CT scan shows a 16-cm soft-tissue attenuation mass involving the esophagus.

View larger version (138K): [in a new window]   Figure 24a.  GIST arising from the small bowel mesentery in a 65-year-old man with abdominal pain. (a) Intravenous contrast-enhanced CT scan shows a 15-cm mass in the small bowel mesentery that contains areas of contrast enhancement and low attenuation (white arrows). There are adjacent metastatic lesions in the mesentery (black arrows). (b) CT scan through the upper abdomen shows liver metastases and intraperitoneal spread of tumor (arrow).

View larger version (132K): [in a new window]   Figure 24b.  GIST arising from the small bowel mesentery in a 65-year-old man with abdominal pain. (a) Intravenous contrast-enhanced CT scan shows a 15-cm mass in the small bowel mesentery that contains areas of contrast enhancement and low attenuation (white arrows). There are adjacent metastatic lesions in the mesentery (black arrows). (b) CT scan through the upper abdomen shows liver metastases and intraperitoneal spread of tumor (arrow).