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Fibromatosis refers to a group of benign, fibroblastic proliferations that range from superficial (fascial) to deep-seated (musculoaponeurotic) lesions. While they lack metastatic potential, deep fibromatoses can be locally aggressive, infiltrate adjacent structures, and recur after resection.
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| Superficial fibromatosis | Deep fibromatosis |
|---|---|
| Palmar (‣ ) | ‣ |
| Plantar (‣ ) | ‣ |
| Penile (‣ ) |
| Factor | Role |
|---|---|
| Trauma / microtrauma | Repetitive injury (especially in plantar/palmar fibromatosis) |
| Hormonal influence | Estrogen sensitivity (desmoid tumors) |
| Genetic syndromes | Familial adenomatous polyposis (FAP), particularly Gardner syndrome |
| Mutations | CTNNB1 (β-catenin) in sporadic desmoids; APC in FAP-related |
| Type | Symptoms |
|---|---|
| Palmar fibromatosis | Nodular thickening of palmar fascia → finger contracture |
| Plantar fibromatosis | Firm nodules in sole, may cause pain while walking |
| Peyronie’s disease | Fibrous plaque in penis → painful curvature |
| Desmoid tumor | Firm, deep-seated mass; may be painless or cause compression symptoms depending on site |
MRI – Preferred Modality
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MRI hallmark in desmoid tumors: "Band sign" – low-signal fibrous bands on all sequences.
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| Subtype | T1-weighted | T2-weighted | Post-contrast |
|---|---|---|---|
| Superficial | Iso- to hypointense to muscle | Variable; usually low-to-intermediate | Mild or no enhancement |
| Desmoid (deep) | Isointense to muscle | Heterogeneous, variable (T2 hyperintense centrally, low peripherally due to collagen) | Variable enhancement; can be intense in cellular areas |
Other modalities:
| Modality | Imaging features |
|---|---|
| US | • Hypoechoic or heterogeneous nodules |
| • May show internal vascularity with Doppler | |
| CT | • Soft tissue mass |
| • No calcification or necrosis | |
| • Infiltrative appearance, may entrap bowel or vessels |
Deep fibromatosis differentials: