PMC5748304_01
2012 Coronal enhanced (a) and axial enhanced (b) CT showing hypovascular solid mass (white arrow) in the mesentery of the right lower quadrant.
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CT revealed an ill-defined hypoattenuating solid mass in the small bowel mesentery (Figure 1), with slight displacement of adjacent small bowel loops and mild enhancement.
Coronal enhanced (a) and axial enhanced (b) CT performed 4 years later, showing recurrent hypovascular solid mass (white arrow) in the mesentery of the right lower quadrant.
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CT was repeated showing a recurrent irregular solid hypoattenuating mass in the mesentery of the right lower quadrant (Figure 2). In the four-month interval between most recent scans the mass had grown significantly from 5 x 4 cm on CT to 8 x 7 cm on MR (Figures 2 and 3, resp.).
MRI T2 sequence (a), T1 unenhanced sequence (b), and T1 enhanced sequence (c), performed four months following most recent CT. This shows a solid mass (white arrow) of mixed signal intensity on T2, with mild enhancement, in the mesentery of the right lower quadrant that has increased in size from most recent CT.
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In the four-month interval between most recent scans the mass had grown significantly from 5 x 4 cm on CT to 8 x 7 cm on MR (Figures 2 and 3, resp.).
Low power view of the lesion in relation to the mucosa and muscular layer of the small bowel. The pink area at the bottom half of the image is all tumor.
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The tumor did not invade surrounding fat or bowel (Figure 4).
Medium power view (x20) is H&E stain of the tumor showing spindle cells (fibroblasts in sweeping fascicles).
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Microscopically the lesion was composed of fibroblasts arranged in sweeping fascicles (Figure 5).
IHC stain for beta-catenin (x20) showing characteristic nuclear staining, confirming the diagnosis of fibromatosis.
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Beta-catenin was diffusely positive (Figure 6).