DOI: 10.1148/rg.264055166
Evaluation of Benign and Malignant Rectal Lesions with CT Colonography and Endoscopic Correlation1
Alvin C. Silva, MD,
Eric A. Vens, MD,
Amy K. Hara, MD,
Joel G. Fletcher, MD,
Jeff L. Fidler, MD and
C. Daniel Johnson, MD
1 From the Department of Diagnostic Radiology, Mayo Clinic, 13400 E Shea Blvd, Scottsdale, AZ 85259 (A.C.S., E.A.V., A.K.H.); and the Department of Radiology, Mayo Clinic, Rochester, Minn (J.G.F., J.L.F., C.D.J.). Recipient of Cum Laude and Excellence in Design awards for an education exhibit at the 2004 RSNA Annual Meeting. Received August 25, 2005; revision requested September 2 and received November 4; accepted November 7. A.K.H. has a licensure agreement with GE Medical Systems; all remaining authors have no financial relationships to disclose.
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Figure 1a. Drawings illustrate the normal anatomy (a) and pathologic lesions (b) of the rectum.
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Figure 1b. Drawings illustrate the normal anatomy (a) and pathologic lesions (b) of the rectum.
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Figure 2a. Metastatic rectal adenocarcinoma with lung metastases. (a–c) Three-dimensional (a), endoscopic (b), and axial 2D (c) images show a polypoid mass (arrows) in the rectum. Note the extension of the mass into the perirectal fat on the right side (arrowheads in c). (d) Axial 2D image reveals a noncalcified lung nodule (arrow).
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Figure 2b. Metastatic rectal adenocarcinoma with lung metastases. (a–c) Three-dimensional (a), endoscopic (b), and axial 2D (c) images show a polypoid mass (arrows) in the rectum. Note the extension of the mass into the perirectal fat on the right side (arrowheads in c). (d) Axial 2D image reveals a noncalcified lung nodule (arrow).
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Figure 2c. Metastatic rectal adenocarcinoma with lung metastases. (a–c) Three-dimensional (a), endoscopic (b), and axial 2D (c) images show a polypoid mass (arrows) in the rectum. Note the extension of the mass into the perirectal fat on the right side (arrowheads in c). (d) Axial 2D image reveals a noncalcified lung nodule (arrow).
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Figure 2d. Metastatic rectal adenocarcinoma with lung metastases. (a–c) Three-dimensional (a), endoscopic (b), and axial 2D (c) images show a polypoid mass (arrows) in the rectum. Note the extension of the mass into the perirectal fat on the right side (arrowheads in c). (d) Axial 2D image reveals a noncalcified lung nodule (arrow).
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Figure 3a. Rectal adenocarcinoma. (a–c) Three-dimensional (a), endoscopic (b), and axial 2D (c) images demonstrate an irregular mass (arrows) in the rectum. An associated enlarged perirectal lymph node (arrowhead in c) upstages the histologically proved adenocarcinoma from stage II to stage III. (d) Axial 2D image obtained at the level of the midabdomen reveals lymphadenopathy (arrows) along the course of the IMV (arrowhead).
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Figure 3b. Rectal adenocarcinoma. (a–c) Three-dimensional (a), endoscopic (b), and axial 2D (c) images demonstrate an irregular mass (arrows) in the rectum. An associated enlarged perirectal lymph node (arrowhead in c) upstages the histologically proved adenocarcinoma from stage II to stage III. (d) Axial 2D image obtained at the level of the midabdomen reveals lymphadenopathy (arrows) along the course of the IMV (arrowhead).
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Figure 3c. Rectal adenocarcinoma. (a–c) Three-dimensional (a), endoscopic (b), and axial 2D (c) images demonstrate an irregular mass (arrows) in the rectum. An associated enlarged perirectal lymph node (arrowhead in c) upstages the histologically proved adenocarcinoma from stage II to stage III. (d) Axial 2D image obtained at the level of the midabdomen reveals lymphadenopathy (arrows) along the course of the IMV (arrowhead).
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Figure 3d. Rectal adenocarcinoma. (a–c) Three-dimensional (a), endoscopic (b), and axial 2D (c) images demonstrate an irregular mass (arrows) in the rectum. An associated enlarged perirectal lymph node (arrowhead in c) upstages the histologically proved adenocarcinoma from stage II to stage III. (d) Axial 2D image obtained at the level of the midabdomen reveals lymphadenopathy (arrows) along the course of the IMV (arrowhead).
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Figure 4a. Valves of Houston. Three-dimensional (a) and sagittal 2D (b) images demonstrate three valves of Houston: superior, middle, and inferior (arrows). The polypoid mass seen in a (arrowhead) represents retained fecal material.
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Figure 4b. Valves of Houston. Three-dimensional (a) and sagittal 2D (b) images demonstrate three valves of Houston: superior, middle, and inferior (arrows). The polypoid mass seen in a (arrowhead) represents retained fecal material.
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Figure 5a. Adenocarcinoma compressed by a rectal balloon. (a) Endoscopic image shows a rectal carcinoma (arrows) that was not evident at 3D endoluminal CT colonography. (b) On an axial 2D image, the mass (arrow) is being compressed to the right by a rectal balloon. Although the balloon cannot be observed directly, its presence can be inferred by displacement of the rectal soft tissue away from the rectal tube (arrowhead). Histologic findings helped identify adenocarcinoma.
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Figure 5b. Adenocarcinoma compressed by a rectal balloon. (a) Endoscopic image shows a rectal carcinoma (arrows) that was not evident at 3D endoluminal CT colonography. (b) On an axial 2D image, the mass (arrow) is being compressed to the right by a rectal balloon. Although the balloon cannot be observed directly, its presence can be inferred by displacement of the rectal soft tissue away from the rectal tube (arrowhead). Histologic findings helped identify adenocarcinoma.
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Figure 6a. Sessile polypoid adenoma. Three-dimensional (a), endoscopic 2D (b), and axial unenhanced 2D (c) images demonstrate a polypoid mass (arrow) with central ulceration. Findings at endoscopic snare biopsy confirmed an adenoma.
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Figure 6b. Sessile polypoid adenoma. Three-dimensional (a), endoscopic 2D (b), and axial unenhanced 2D (c) images demonstrate a polypoid mass (arrow) with central ulceration. Findings at endoscopic snare biopsy confirmed an adenoma.
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Figure 6c. Sessile polypoid adenoma. Three-dimensional (a), endoscopic 2D (b), and axial unenhanced 2D (c) images demonstrate a polypoid mass (arrow) with central ulceration. Findings at endoscopic snare biopsy confirmed an adenoma.
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Figure 7a. Villous adenoma. Three-dimensional (a), endoscopic 2D (b), and axial 2D (c) images demonstrate a polypoid rectal mass (arrow in a, arrowhead in b and c). The frondlike surface of the mass can be appreciated on the 3D and endoscopic views. At biopsy, the mass proved to be a villous adenoma.
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Figure 7b. Villous adenoma. Three-dimensional (a), endoscopic 2D (b), and axial 2D (c) images demonstrate a polypoid rectal mass (arrow in a, arrowhead in b and c). The frondlike surface of the mass can be appreciated on the 3D and endoscopic views. At biopsy, the mass proved to be a villous adenoma.
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Figure 7c. Villous adenoma. Three-dimensional (a), endoscopic 2D (b), and axial 2D (c) images demonstrate a polypoid rectal mass (arrow in a, arrowhead in b and c). The frondlike surface of the mass can be appreciated on the 3D and endoscopic views. At biopsy, the mass proved to be a villous adenoma.
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Figure 8a. Flat villous adenoma. (a, b) Three-dimensional (a) and endoscopic (b) images show a mass (arrow) with a frondlike surface. Note that on the 3D view, the mass is partially obscured by the rectal tube (R). (c) Two-dimensional image shows the rectal tube (R) abutting the mass. Compare the normal thin rectal wall (arrowheads) with the focal elongated wall thickening (arrows) caused by the flat lesion. The mass proved to be villous adenoma at biopsy.
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Figure 8b. Flat villous adenoma. (a, b) Three-dimensional (a) and endoscopic (b) images show a mass (arrow) with a frondlike surface. Note that on the 3D view, the mass is partially obscured by the rectal tube (R). (c) Two-dimensional image shows the rectal tube (R) abutting the mass. Compare the normal thin rectal wall (arrowheads) with the focal elongated wall thickening (arrows) caused by the flat lesion. The mass proved to be villous adenoma at biopsy.
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Figure 8c. Flat villous adenoma. (a, b) Three-dimensional (a) and endoscopic (b) images show a mass (arrow) with a frondlike surface. Note that on the 3D view, the mass is partially obscured by the rectal tube (R). (c) Two-dimensional image shows the rectal tube (R) abutting the mass. Compare the normal thin rectal wall (arrowheads) with the focal elongated wall thickening (arrows) caused by the flat lesion. The mass proved to be villous adenoma at biopsy.
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Figure 9a. Rectal adenocarcinoma. Three-dimensional (a), endoscopic (b), and axial 2D (c) images show an irregular mass (arrow) in the rectum. Pathologic findings helped identify adenocarcinoma.
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Figure 9b. Rectal adenocarcinoma. Three-dimensional (a), endoscopic (b), and axial 2D (c) images show an irregular mass (arrow) in the rectum. Pathologic findings helped identify adenocarcinoma.
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Figure 9c. Rectal adenocarcinoma. Three-dimensional (a), endoscopic (b), and axial 2D (c) images show an irregular mass (arrow) in the rectum. Pathologic findings helped identify adenocarcinoma.
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Figure 10a. Gastrointestinal multiple lymphomatous polyposis. (a, b) Three-dimensional (a) and endoscopic (b) images demonstrate innumerable polypoid masses. These masses were initially thought to represent familial polyposis but were diagnosed as multiple lymphomatous polyposis at pathologic analysis. (c) Axial 2D image shows diffuse mucosal irregularity with involvement of the rectal fold (arrow). Arrowhead indicates the rectal tube.
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Figure 10b. Gastrointestinal multiple lymphomatous polyposis. (a, b) Three-dimensional (a) and endoscopic (b) images demonstrate innumerable polypoid masses. These masses were initially thought to represent familial polyposis but were diagnosed as multiple lymphomatous polyposis at pathologic analysis. (c) Axial 2D image shows diffuse mucosal irregularity with involvement of the rectal fold (arrow). Arrowhead indicates the rectal tube.
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Figure 10c. Gastrointestinal multiple lymphomatous polyposis. (a, b) Three-dimensional (a) and endoscopic (b) images demonstrate innumerable polypoid masses. These masses were initially thought to represent familial polyposis but were diagnosed as multiple lymphomatous polyposis at pathologic analysis. (c) Axial 2D image shows diffuse mucosal irregularity with involvement of the rectal fold (arrow). Arrowhead indicates the rectal tube.
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Figure 11a. Leiomyoma. (a, b) Three-dimensional (a) and axial 2D (b) images show a small polypoid lesion (arrow) in the rectum. The mucosa overlying the lesion is intact, and the attenuation of the lesion is similar to that of muscle. (c) Image obtained during endoscopic snare biopsy also shows the lesion (arrow).
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Figure 11b. Leiomyoma. (a, b) Three-dimensional (a) and axial 2D (b) images show a small polypoid lesion (arrow) in the rectum. The mucosa overlying the lesion is intact, and the attenuation of the lesion is similar to that of muscle. (c) Image obtained during endoscopic snare biopsy also shows the lesion (arrow).
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Figure 11c. Leiomyoma. (a, b) Three-dimensional (a) and axial 2D (b) images show a small polypoid lesion (arrow) in the rectum. The mucosa overlying the lesion is intact, and the attenuation of the lesion is similar to that of muscle. (c) Image obtained during endoscopic snare biopsy also shows the lesion (arrow).
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Figure 12a. Endometrial sarcoma. (a, b) Three-dimensional (a) and endoscopic (b) images show a bilobed polypoid mass (arrow) projecting into the rectal lumen. (c) On an axial contrast material–enhanced 2D image, the polypoid mass (arrow) clearly projects into the colon and is contiguous with a uterine mass (M). (Reprinted, with permission, from reference 37.)
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Figure 12b. Endometrial sarcoma. (a, b) Three-dimensional (a) and endoscopic (b) images show a bilobed polypoid mass (arrow) projecting into the rectal lumen. (c) On an axial contrast material–enhanced 2D image, the polypoid mass (arrow) clearly projects into the colon and is contiguous with a uterine mass (M). (Reprinted, with permission, from reference 37.)
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Figure 12c. Endometrial sarcoma. (a, b) Three-dimensional (a) and endoscopic (b) images show a bilobed polypoid mass (arrow) projecting into the rectal lumen. (c) On an axial contrast material–enhanced 2D image, the polypoid mass (arrow) clearly projects into the colon and is contiguous with a uterine mass (M). (Reprinted, with permission, from reference 37.)
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Figure 13a. Rectal stricture from known Crohn disease. (a) Oblique volume-rendered image demonstrates focal collapse (arrows) near the rectosigmoid junction due to an inflammatory stricture. (b–d) Three-dimensional (b), endoscopic (c), and axial 2D prone (d) images show the stricture lumen (arrow).
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Figure 13b. Rectal stricture from known Crohn disease. (a) Oblique volume-rendered image demonstrates focal collapse (arrows) near the rectosigmoid junction due to an inflammatory stricture. (b–d) Three-dimensional (b), endoscopic (c), and axial 2D prone (d) images show the stricture lumen (arrow).
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Figure 13c. Rectal stricture from known Crohn disease. (a) Oblique volume-rendered image demonstrates focal collapse (arrows) near the rectosigmoid junction due to an inflammatory stricture. (b–d) Three-dimensional (b), endoscopic (c), and axial 2D prone (d) images show the stricture lumen (arrow).
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Figure 13d. Rectal stricture from known Crohn disease. (a) Oblique volume-rendered image demonstrates focal collapse (arrows) near the rectosigmoid junction due to an inflammatory stricture. (b–d) Three-dimensional (b), endoscopic (c), and axial 2D prone (d) images show the stricture lumen (arrow).
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Figure 14a. SRUS. Three-dimensional (a), axial 2D (b), and endoscopic (c) images demonstrate an irregular rectal mass (arrows), a finding that is worrisome for neoplasm. However, histopathologic and clinical features were characteristic of SRUS.
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Figure 14b. SRUS. Three-dimensional (a), axial 2D (b), and endoscopic (c) images demonstrate an irregular rectal mass (arrows), a finding that is worrisome for neoplasm. However, histopathologic and clinical features were characteristic of SRUS.
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Figure 14c. SRUS. Three-dimensional (a), axial 2D (b), and endoscopic (c) images demonstrate an irregular rectal mass (arrows), a finding that is worrisome for neoplasm. However, histopathologic and clinical features were characteristic of SRUS.
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Figure 15a. Air-containing stool mimicking a sessile polyp in the same patient as in Figure 14. (a) Endoluminal image reveals a polyplike mass (arrow) on the dependent wall of the rectum. (b) Axial 2D image helps confirm internal heterogeneity (arrow) due to foci of air, a finding that is characteristic of stool.
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Figure 15b. Air-containing stool mimicking a sessile polyp in the same patient as in Figure 14. (a) Endoluminal image reveals a polyplike mass (arrow) on the dependent wall of the rectum. (b) Axial 2D image helps confirm internal heterogeneity (arrow) due to foci of air, a finding that is characteristic of stool.
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Figure 16a. Mobile stool in the rectum. Three-dimensional (a), axial 2D supine (b), and right lateral decubitus (c) images demonstrate a homogeneous filling defect (arrow) that moves from the posterior wall to the right lateral wall on separate acquisitions, a finding that is consistent with stool. Arrowhead in c indicates the tip of an enema tube.
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Figure 16b. Mobile stool in the rectum. Three-dimensional (a), axial 2D supine (b), and right lateral decubitus (c) images demonstrate a homogeneous filling defect (arrow) that moves from the posterior wall to the right lateral wall on separate acquisitions, a finding that is consistent with stool. Arrowhead in c indicates the tip of an enema tube.
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Figure 16c. Mobile stool in the rectum. Three-dimensional (a), axial 2D supine (b), and right lateral decubitus (c) images demonstrate a homogeneous filling defect (arrow) that moves from the posterior wall to the right lateral wall on separate acquisitions, a finding that is consistent with stool. Arrowhead in c indicates the tip of an enema tube.
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Figure 17a. Internal hemorrhoids in a patient with a history of invasive melanoma. Three-dimensional (a) and axial contrast-enhanced 2D (b) images demonstrate dilated vasculature (arrow) in the anterior rectal wall. This finding was initially interpreted as a hypervascular mass that was worrisome for metastatic melanoma. However, endoscopy performed at another institution demonstrated only internal hemorrhoids.
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Figure 17b. Internal hemorrhoids in a patient with a history of invasive melanoma. Three-dimensional (a) and axial contrast-enhanced 2D (b) images demonstrate dilated vasculature (arrow) in the anterior rectal wall. This finding was initially interpreted as a hypervascular mass that was worrisome for metastatic melanoma. However, endoscopy performed at another institution demonstrated only internal hemorrhoids.
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Figure 18a. Streak artifact from a hip prosthesis obscuring a flat adenoma. (a) Endoscopic image demonstrates a small mass (arrows). (b) Three-dimensional image fails to depict the mass. (c) On an axial 2D image (lung windowing), the mass (arrow) is mostly obscured due to severe degradation by streak artifact caused by hip arthroplasty hardware. Endoscopic biopsy yielded pathologic findings of adenoma.
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Figure 18b. Streak artifact from a hip prosthesis obscuring a flat adenoma. (a) Endoscopic image demonstrates a small mass (arrows). (b) Three-dimensional image fails to depict the mass. (c) On an axial 2D image (lung windowing), the mass (arrow) is mostly obscured due to severe degradation by streak artifact caused by hip arthroplasty hardware. Endoscopic biopsy yielded pathologic findings of adenoma.
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Figure 18c. Streak artifact from a hip prosthesis obscuring a flat adenoma. (a) Endoscopic image demonstrates a small mass (arrows). (b) Three-dimensional image fails to depict the mass. (c) On an axial 2D image (lung windowing), the mass (arrow) is mostly obscured due to severe degradation by streak artifact caused by hip arthroplasty hardware. Endoscopic biopsy yielded pathologic findings of adenoma.
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Copyright © 2006 by the Radiological Society of North America.
