A low power of a<unk> -type<unk>  showing entrapped fat. The tumors are unencapsulated and poorly circumscribed, showing a firm, white cut surface. Most tumors are about 3.5 cm, but can be up to 8 cm. By microscopic examination, there are haphazardly arranged thick collagen fibers, with a low cellularity and no pleomorphism. There are usually entrapped fat cells, skeletal muscle, and peripheral nerves. The may be perineural fibrosis. The elastic fibers may be altered, which is why an elastofibroma is considered in the differential diagnosis.<unk>  Immunohistochemistry The tumor cells are strongly positive for vimentin, CD34, and sometimes with CD99. There is often (up to 2/3rds) a nuclear reaction with β-catenin.
Nuchal fibroma
Dentigerous cyst
Acrospiroma
Paradental cyst
Tornwaldt cyst
Ganglion cyst
Tarlov cyst
Colloid cyst