Extra abdominal fibromatosis
Case Detail
| Anatomy: Musculoskeletal |
Heather Borders, MD |
| Diagnostic Category: Neoplasia Benign |
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| Created: about 1 year ago |
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| Updated: about 1 year ago |
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| Tags:
PEDS
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| Modality/Study Types:
MRI
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Activities: PDF ImageJA |
History
13 month old female with ill defined scapular region mass that has been present since birth but is recently growing.
Case Images
Diagnosis
Extra abdominal fibromatosis/gardner fibroma features
Findings
Iso to hypo intense T1, hypointense T2 non enhancing tissue infiltrating fascial planes in the right paraspinal and scapular region. Infiltration of right paraspinal muscles with otherwise sparing of muscles.
Discussion
Fibromatosis typically appears as painless soft tissue swelling or masses in the extremities usually during first two years of life. They are slightly more prominent in boys.
The lesion typically manifests as a firm nodular mass usually within the skeletal muscle, adjacent fascia or periostium. The most common locations are in the head and neck. Other sites frequently affected include the shoulder thigh and foot.
These tumors are locally aggressive, infiltrating muscles, vessels, nerves, fascia, tendons and subcutaneous fat.
The histologic features make differentiation from fibro sarcoma difficult. The lesions tend to recur after surgery.
The radiograph demonstrates a soft tissue mass, or swelling with occasional bone defect or scalloped surface.
The CT scans are usually non-specific. The lesions may be hypo attenuating relative to skeletal muscles but are typically iso-attenuating or even hyper attenuating.
MRI is the best imaging modality. Infantile fibromatosis is an inter-muscular lesion, with frequent muscular invasion. Linear extension along fascial planes is frequent. The initial reports suggest decreased signal intensity on T1 and T2 weighted images. Hypocellularity and abundant collagen produces low signal on T2 weighted images. Marked cellularity shows high signal on T2 weighted images. The deep fibromatoses typically demonstrate moderate to marked enhancement after administration of gadolinium contrast material, particularly in less collagenized and more cellular regions. Only 10% of lesions lack significant enhancement at MR imaging.
In this case, the lesion is very hypointense on T2 and lacks enhancement suggesting high collagen content.
Reference
Imaging of Musculoskeletal Fibromatosis Mark R. Robbin, MD, et al. May 2001 RadioGraphics, 21, 585-600.



