๐ ็ธฝ็ฎ้ ๏ฝ ๐ ่ฑๆๅๆ๏ผๆฌ็ฏ๏ผ ๏ฝ ๐ ๅฎๆด็ฟป่ญฏ ๏ฝ โญ ็ฒพ่ฏ็ญ่จ
Gardner fibroma
Gardner fibroma
Clinical features Gardner fibroma is a benign soft tissue tumor identical to nuchal fibroma, presenting in patients with Gardner syndrome (colonic adenomatous polyposis, epidermoid cysts), a familial adenosis poliposis (FAP) variant also associated with germline inactivating mutations in APC.1 The tumor may be the first manifestation of the disease and lesions tend to be multiple, arising in children and at different sites including the neck, head, trunk and extremities.2โ4 Desmoid fibromatosis may develop at the sites of Gardner fibromas and the relationship of these two lesions is unclear. Lesions are poorly circumscribed, slow growing and range in size from 2 to 10โฏcm. Local recurrence is possible.
Pathogenesis and histologic features Fibromatosis colli appears to be related to trauma, as often there is a history of intrauterine positional abnormalities or complicated deliveries.1โ3 Other musculoskeletal abnormalities can also be seen. An association with Wiedemann-Steiner syndrome has been reported.7
Histology shows partial replacement of skeletal muscle by collagenous tissue with poor cellularity. Degenerate muscle fibers are commonly seen.
By immunohistochemistry, tumor cells are positive SMA but negative for beta-catenin.
Differential diagnosis Distinction from other types of fibromatosis is based on the typical clinical presentation and the presence of a predominantly collagenous hypocellular mass in fibromatosis colli. In addition, aberrant nuclear positivity for ฮฒ-catenin is seen in most cases of fibromatosis, excepting superficial fibromatoses.
Pathogenesis and histologic features These tumors are driven by overaction of the Wnt/ฮฒ-catenin pathway secondary to inactivation of the APC gene.1,5,6 Tumors are identical to nuchal fibroma (see above) but some lesions are more cellular and lack a lobular growth pattern.7 A case associated with elastosis, traumatic neuroma and a MUTYH polymorphism has been described.8 Immunohistochemistry to examine for nuclear accumulation of ฮฒ-catenin can be helpful, but is not entirely specific.9,10