Coloretcal carcinoma

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Information about Coloretcal carcinoma

Published on May 16, 2019

Author: DrNaveedQuetta

Source: slideshare.net

1. Dr. Naveed AshrafRadiologic Pictorial Review Colorectal Carcinoma 1

2. Dr. Naveed AshrafRadiologic Pictorial Review TEACHING POINTS CT : is generally used for assessing the presence of any metastatic disease and not for determining the local T staging. MRI: is used for the local staging of rectal cancer (considered a separate entity to colon cancer as its pelvic location reduces the ability to obtain wide resection margins with a consequent increased risk of local recurrence) Mesorectal fascia: encloses the mesorectum (which contains the draining lymphatic nodes and vessels) . Nodal spread usually occurs cranially within this compartment Positive circumferential resection margin (CRM): if there is tumour within 1 mm of the mesorectal fascia this requires preoperative chemotherapy Local nodal involvement: It is important to record whether a suspicious node lies within 1 mm of the CRM FDG PET-CT: This is useful for detecting extracolonic disease (lesions >1 cm) . It is the most accurate modality for detecting recurrent pelvic cancer (scar tissue does not demonstrate increased FDG PET uptake) Endorectal US : This allows for better differentiation of the rectal wall layers than MRI . It is used to assess early tumour involvement and select T1N0 cases for local excision 2

3. Dr. Naveed AshrafRadiologic Pictorial Review Adenoma Carcinoma sequence. . A 1-cm polyp (arrow) is demonstrated in the proximal transverse colon. B. Seventeen years later, the small polyp has grown into a full-blown polypoid carcinoma (arrow). 3

4. Dr. Naveed AshrafRadiologic Pictorial Review In another patient, there are adenomas in the distal sigmoid (arrowhead ), a polypoid carcinoma near the apex of the sigmoid, and an annular carcinoma more proximally in the sigmoid colon. 4

5. Dr. Naveed AshrafRadiologic Pictorial Review Lesions missed at endoscopy identified on barium enema. A. There is a small sessile polyp (arrow) behind a fold at the rectosigmoid junction. This lesion was missed twice on sigmoidoscopy and was finally detected at the third sigmoidoscopic examination. B. A small polyp (arrow) is situated behind a fold at an area of angulation at the junction of the sigmoid and the descending colon. This polyp was missed on two colonoscopic examinations and was found on the third. 5

6. Dr. Naveed AshrafRadiologic Pictorial Review Lesions missed at endoscopy identified on barium enema. Polypoid carcinoma is just proximal to the rectosigmoid junction. This lesion was missed on several sigmoidoscopic and colonoscopic examinations and was confirmed only at surgery. Polypoid carcinoma at the hepatic flexure was missed on initial colonoscopy. 6

7. Dr. Naveed AshrafRadiologic Pictorial Review Distribution of colorectal polyps (based on 108 consecutive polyps). Approximately 60% of the polyps are in the rectum and sigmoid colon. 7

8. Dr. Naveed AshrafRadiologic Pictorial Review Villous adenomas. A. A flat tumor in the descending colon with an irregular surface suggestive of a villous adenoma. This was a villoglandular polyp. B. Typical villous tumor in the sigmoid colon. This tumor exhibits the typical, irregular, frondlike surface of a villous tumor. It was a malignant villous adenoma. 8

9. Dr. Naveed AshrafRadiologic Pictorial Review Double-contrast barium enema and colonoscopy features of polyps. A. The bowler hat sign representing a sessile polyp. B. Mexican hat sign. This is the typical appearance of a pedunculated polyp seen end-on. The outer ring represents the head of the polyp, and the inner ring represents the stalk. 9

10. Dr. Naveed AshrafRadiologic Pictorial Review Carpet lesions. A. Typical carpet lesion (arrow) in the cecum. B. Malignant transformation in a carpet lesion. An obvious polypoid carcinoma is seen in the ascending colon. Surrounding the polypoid lesion is the mucosal change representing the underlying adenoma. 10

11. Dr. Naveed AshrafRadiologic Pictorial Review CT of benign polyps. A. Axial thin-section MDCT scan identifies a sessile polyp (arrow) on the left wall of the proximal sigmoid colon, which was confirmed by colonoscopy in a patient with carcinoma of the cecum and familial polyposis syndrome. B. Axial thin-section MDCT below level shown in A demonstrates a second polyp (arrow) in the small bowel. 11

12. Dr. Naveed AshrafRadiologic Pictorial Review Early colon cancers: polypoid carcinoma with a pedicle in 29-year-old man with rectal bleeding. A pedunculated polyp in the descending colon (large arrow) has a typically benign appearance. This was removed at colonoscopy and was found to be a carcinoma with invasion of the stalk. The smaller lesions (small arrows) were hyperplastic polyps. 12

13. Dr. Naveed AshrafRadiologic Pictorial Review Pedunculated early cancer. Early carcinoma (arrow) with a short, thick stalk. 13

14. Dr. Naveed AshrafRadiologic Pictorial Review Lateral view shows an ulcerated plaquelike carcinoma etched in white (arrows) at the rectosigmoid junction. 14

15. Dr. Naveed AshrafRadiologic Pictorial Review Large polypoid carcinoma (arrows) at the splenic flexure 15

16. Dr. Naveed AshrafRadiologic Pictorial Review Annular “apple core” lesion. 16

17. Dr. Naveed AshrafRadiologic Pictorial Review Synchronous tumors. A. A nearly obstructing polypoid carcinoid is seen in the transverse colon, and a second adenoma is seen in the sigmoid colon. B. Multiple polypoid carcinomas (arrows) in the ascending colon. 17

18. Dr. Naveed AshrafRadiologic Pictorial Review Carcinoma in a patient with diverticulosis. The polypoid carcinoma (arrow) is more difficult to recognize in the presence of extensive diverticulosis. 18

19. Dr. Naveed AshrafRadiologic Pictorial Review19

20. Dr. Naveed AshrafRadiologic Pictorial Review TNM-stage The treatment of a patient with rectal cancer depends on the TNM- stage and whether the MRF is involved. T-staging T1 and T2 tumors are limited to the bowel wall. T3 tumors grow through the bowel wall and infiltrate the mesorectal fat. They are further differentiated in: T3a: < 1mm extension beyond muscularis propria T3b: 1-5 mm extension beyond muscularis propria T3c: 5 - 15 mm extension beyond muscularis propria T3d: > 15 mm T3 MRF+ (MRF positive) tumor within 1mm of MRF MRF- (MRF Negative) no tumor within 1 mm of MRF The N-stage is based on the number of suspicious lymph nodes: N0 no suspicious nodes N1 1-3 suspicious nodes N2 ⩾ 4 suspicious nodes 20

21. Dr. Naveed AshrafRadiologic Pictorial Review Large intraluminal mass in a distended rectum without extension beyond bowel wall (T2N0M0). A. A thin-section MDCT scan in the arterial phase demonstrates a very large intraluminal mass (large arrows) that appears to arise from the anterior wall of the rectum. Bladder wall (thin arrows) is clearly separated from the rectal wall by a thin layer of fat. B. Several centimeters below the level of A, the fat plane between bladder wall (thin arrows) and the mass (large arrow) in the anterior rectal wall remains intact. 21

22. Dr. Naveed AshrafRadiologic Pictorial Review A. Coronal MPR demonstrates the large intraluminal component of the mass (large arrows) and the wall thickening (small arrows), with a smooth outer border. B. The sagittal multiplanar reformatted image demonstrates a clear fat plane between the bladder wall (small arrow) and thickened rectal wall (thin arrow). Both MPRs confirm absence of perirectal infiltration. The large intraluminal mass (large arrows) is also appreciated. 22

23. Dr. Naveed AshrafRadiologic Pictorial Review Axial thin-section (2.5 mm) MDCT scan of the rectum in the arterial phase and with rectal administration of water demonstrates focal thickening of the anterior and right lateral rectal wall (long arrows). The outer margin of the rectum is smooth and well preserved. The rectal tube also is seen (arrowhead ). No abnormal lymph nodes are identified (CT stage II). 23

24. Dr. Naveed AshrafRadiologic Pictorial Review Axial MDCT scan obtained with a slice thickness of 5 mm and in the portal venous phase also shows the lesion (arrows) but the outer tumor margins are ill defined and less well assessed. 24

25. Dr. Naveed AshrafRadiologic Pictorial Review Rectal carcinoma with microextension into perirectal fat, T3N0M0. The wall of the distal sigmoid colon is circumferentially thickened as a result of a concentric adenocarcinoma, and its outer margins are smooth. No adenopathy or invasion of fat is demonstrated 25

26. Dr. Naveed AshrafRadiologic Pictorial Review Adenocarcinoma of the rectum confined to the rectal wall with perirectal lymph nodes (T2N1M0; Dukes’ stage C1). A. MDCT scan demonstrates minimal but diffuse wall thickening (red arrows). Mesorectal fascia is well shown (arrowheads). Perirectal lymph nodes (white arrows) are seen in the perirectal fat adjacent to left lateral wall of rectum. MDCT was performed after one course of radiation, which probably caused the diffuse wall thickening. B. MDCT scan slightly below the level in A reveals asymmetric nodular thickening of left lateral wall of the rectum (arrows) without extension of tumor into perirectal fat. 26

27. Dr. Naveed AshrafRadiologic Pictorial Review Adenocarcinoma of the sigmoid colon, A, B. T3N0 M0 (Dukes’ stage B2). A. The axial MDCT scan demonstrates a nodular mass along the left lateral wall of the sigmoid colon (arrows) without definite extension beyond the bowl wall. B. In the coronal reconstruction a broad based extension of tumor (arrow) into the pericolonic fat is seen. 27

28. Dr. Naveed AshrafRadiologic Pictorial Review T3N1M0 (Dukes’ stage C1). C. The full extent of the circumferential tumor in the sigmoid colon (arrows) is best demonstrated in the coronal reconstruction. Subtle broad-based stranding (short arrow) suggests extension beyond the bowel wall. D. The sagittal reconstruction demonstrates a small lymph node (short arrow) next to the sigmoid neoplasm (long arrows). 28

29. Dr. Naveed AshrafRadiologic Pictorial Review Rectal carcinoma in posterior and lateral walls (arrows) of rectum (T3N1M0; Dukes’ stage C1). A. Outer borders (arrows) are slightly irregular, but no definite nodularity can be seen. This makes it difficult to distinguish a desmoplastic reaction from actual tumor extension in this case. The patient was diagnosed by MDCT as probably a T3. B. At a level higher than in A, tumor is present only in posterior wall (thick arrow). Water facilitates visualization of intraluminal component of tumor in spite of the presence of feces. Also note hypogastric lymph nodes (thin arrow) that are lateral to mesorectal fascia. 29

30. Dr. Naveed AshrafRadiologic Pictorial Review CT scan of primary invasive rectal adenocarcinoma (T4bN2M1; Dukes’ stage D). A. Large enhancing rectal mass (white arrow) with extension to pelvic sidewalls. Enhanced mass is inseparable from the sacrum (black arrows) and piriformis muscle (arrowhead ) on left. B. Rectal mass (red arrow) directly extends into mesorectal fascia (long arrow). Abnormal internal iliac lymph node (small arrow) also is identified. C. At a level just below the midpole of kidneys, extensive retroperitoneal adenopathy (arrows) is demonstrated. D. Several hepatic metastases (arrows) are seen. 30

31. Dr. Naveed AshrafRadiologic Pictorial Review Sigmoid carcinoma with invasion of uterus (T4bN1M0; Dukes’ stage C2). A. Long segmental thickening (small arrows) of sigmoid wall. Note the absence of wall stratification, which can be seen in diverticulitis. The sigmoid tumor is inseparable from the low-density mass in the uterus (large arrows). B. At a level 5 mm below A, gas (long arrow) is seen, indicating direct invasion of the tumor into uterus with perforation and necrosis. Note ascites (short arrows) along the pelvic sidewall. 31

32. Dr. Naveed AshrafRadiologic Pictorial Review Rectal tumor with direct extension to the mesorectal fascia and locoregional lymphadenopathy (T3N1M0 or Dukes’ stage C2). A. Large rectal mass with broad-based extension of soft tissue (arrows) into perirectal fat and direct invasion of mesorectal fascia (arrowheads). B. Several centimeters above the level of A, rectal wall is markedly thickened but tumor does not extend into piriform muscle (thick arrow) or bladder. Note enlarged perirectal lymph node (thin arrow). 32

33. Dr. Naveed Ashraf 40-year-old woman with upper rectal cancer. This case shows impact of high-resolution oblique T2-weighted imaging on T staging. A, Routine axial plane (dotted lines) planned on sagittal T2-weighted image. Arrow shows tumor axis. B, On axial T2-weighted image, rectal tumor seems to invade posterior surface of uterus (arrowheads). 33

34. Dr. Naveed Ashraf (continued)— This case shows impact of highresolution oblique T2- weighted imaging on T staging. C, Thinner slices with plane (dotted lines) perpendicular to axis of rectum and tumor (arrow) for high-resolution oblique imaging. D, On high-resolution oblique T2-weighted image, there is no invasion of uterus with visible fat plane (arrows) between rectal cancer and uterus. 34

35. Dr. Naveed Ashraf T3 rectal tumors on T2-weighted MR images. A, Low rectal tumor in 58- year-old man with tumoral spiculations (intermediate signal intensity) of mesorectal fat (arrowheads). B, Low rectal tumor in 63-year-old man with nodular extension to mesorectal fat. Double-headed arrow shows shortest distance from most penetrating part of tumor and mesorectal fascia. 35

36. Dr. Naveed Ashraf (continued)—T3 rectal tumors on T2-weighted MR images. C, Midrectal tumor in 80-year-old man with massive extension to mesorectal fat and mesorectal fascia infiltration (arrowheads). Double-headed arrow shows extramural depth of invasion. D, Nontumoral spiculation (low signal intensity) of mesorectal fat without nodular extension to tumor (arrowheads) beyond muscularis propria in 67-year-old woman; pathology revealed T2 tumor. 36

37. Dr. Naveed AshrafRadiologic Pictorial Review Anterior and lateral aspects of upper rectum and anterior aspect of middle rectum are covered with peritoneum (red line). Shortest distance between tumor and circumferential resection margin (blue arrows) is measured as that between most penetrating part of tumor and mesorectal fascia not covered by peritoneum (black line). 37

38. Dr. Naveed Ashraf High-resolution oblique T2-weighted images of two patients with T4 rectal tumors. A, 40-year-old man with rectal tumor invading right seminal vesicle (arrow) and levator ani (arrowheads). B, 53-year-old woman with rectal tumor (asterisk) invading left posterior vaginal wall (arrow). 38

39. Dr. Naveed AshrafRadiologic Pictorial Review Coronal schematic diagram of lower rectum (left) and MR image of lower rectum (right) in 58-year-old woman depict anal sphincter complex and surgical dissection planes. Standard low anterior resection (LAR) is reserved for mid- and high-rectal tumors without invasion to pelvic floor muscles. Intersphincteric resection (ISR) dissects internal anal sphincter at about level of dentate line. Abdominoperineal resection (APR) involves removal of rectum along with sphincter complex. AV = anal verge, EAS = external sphincter complex, IAS = internal anal sphincter, ISP = intersphincteric plane, PR = puborectalis, LA = levator ani. 39

40. Dr. Naveed Ashraf Low rectal cancer in 63-year-old woman. A and B, Axial T2-weighted (A) and contrast-enhanced T1-weighted (B) images depict large locally advanced low rectal cancer invading sphincter complex, extending laterally to right ischiorectal fossa and right obturator externus muscle, and invading anterior vagina. In this patient, conventional abdominoperineal resection (dotted line) would result in positive margin. Wide abdominoperineal excision and pelvic exenteration (solid line) were performed on basis of MRI findings. 40

41. Dr. Naveed Ashraf Malignant pelvic lymphadenopathy with rectal cancer in 71-year-old man. A, Axial T2-weighted image shows three heterogeneous enlarged lymph nodes in upper mesorectum and right obturator region (arrowheads). B, Involved nodes shows heterogeneous enhancement (arrows) on contrast- enhanced T1- weighted image. 41

42. Dr. Naveed AshrafRadiologic Pictorial Review On axial T2-weighted image, two oval nodules suggestive of mesorectal nodes are evident on right (arrowhead) at 9-o’clock position and left (arrow) at 3-o’clock position of rectum. 42

43. Dr. Naveed AshrafRadiologic Pictorial Review Continued- Coronal T2-weighted image of right-side lesion shows irregularly expanded vessel with heterogeneous tumor signal intensity (arrowheads) in vicinity of rectal tumor (asterisk) indicative of Extramural vascular invasion EMVI. 43

44. Dr. Naveed AshrafRadiologic Pictorial Review Continued- Coronal T2-weighted image of left-side lesion (arrow) shows that lesion remains oval in shape, which suggests that lesion is metastatic mesorectal lymph node. 44

45. Dr. Naveed Ashraf Significant pathologic response to chemoradiation therapy (CRT). A, shows large circumferential rectal tumor with intermediate signal intensity B, shows marked fibrosis. 45

46. Dr. Naveed Ashraf Significant pathologic response to chemoradiation therapy (CRT). A, Diffusionweighted image shows restricted diffusion B, shows diffusion is not restricted 46

47. Dr. Naveed Ashraf Significant pathologic response to chemoradiation therapy (CRT). A, shows that tumor enhances. B, shows marked interval decrease in tumor size and enhancement. 47

48. Dr. Naveed Ashraf Significant pathologic response to chemoradiation therapy (CRT). A, PET shows tumor (arrow,) is metabolically active. B, shows marked interval improvement, but there is residual focal uptake of FDG (arrow) along left wall of lower rectum. 48

49. Dr. Naveed Ashraf T2 volumetry for the evaluation of tumor response in a 72-year-old man. (a) Before radiation therapy and chemotherapy, volumetry based on sagittal T2-weighted MR image (red) shows a large mass in the upper rectum with a volume of 95 mL. (b) After radiation therapy and chemotherapy, MR image shows a dramatic reduction in tumor volume (7 mL). 49

50. Dr. Naveed Ashraf DWI for tumor detection in a 56-year-old man with a relapsing rectal tumor. (a) Sagittal T2-weighted MR image does not adequately show the tumor extension. (b) Sagittal diffusion-weighted image at a high b value (b = 1000 sec/mm2) clearly shows the tumor (arrows). DWI has the advantage of higher contrast resolution but is still hampered by lower spatial resolution compared with T2-weighted imaging. Thus, simultaneous use of both data sets provides better results for tumor delineation. DWI is an accurate technique for detecting CRC. 50

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