PMC1182401_01
Imaging of the large bowel 1a) CT scan showing the large lesion in the posterior and left lateral wall of the rectum and 1b) MRI imaging: the distal rectal wall lesion (GANT) is shown to be intramural and free from adjoining structures.
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F1
Tissue plane between this lesion and prostate was not clearly seen but there was no infiltration of the ischiorectal fat (Figure 1a). Magnetic resonance imaging (MRI) showed a very large well-defined mass in the left presacral / ischio-anal fossa contiguous with rectal wall and thus almost certainly arising from one of the elements of the rectal wall (Figure 1b).
Barium enema a) the apple core lesion at the splenic flexure and b) the extrinsic compression in the distal rectum caused by schwannoma.
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F2
Barium enema showed an apple core lesion in the splenic flexure (Figure 2a) as well as narrowing of the distal rectal lumen (Figure 2b).
Resected specimen showing malignant tumour at the splenic flexure, polyp in the descending colon and rectal schwannoma.
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F3
Macroscopic examination of the resected specimen confirmed the malignant tumour in the splenic flexure, the polyp in the descending colon and a 10 x 12 cm tumour with a well-defined pseudocapsule in the postero-lateral wall of the mid and low rectum (Figure 3).
Photomicrograph showing a) cellular (Antoni A) and b) myxoid (Antoni B) areas (hematoxylin and eosin x40).
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F4
Some parts of the tumour were quite cellular while few areas were hypocellular reminiscent of the Antoni A and Antoni B patterns respectively (Figures 4a and 4b).
Immunohistochemical staining of the rectal lesion with a) CD34, b) S100, c) Vimentin and d) NSE (original magnification x40).
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F5
S100 (Figures 5a, 5b, 5c and 5d). Smooth muscle markers actin and desmin were negative.