Keloid : Differential Diagnosis

Comments:
Differential Diagnosis: The differential diagnosis of keloid includes: hypertrophic scar, collagenoma, acne keloidalis, and keloidal dermatofibroma.

Hypertrophic scars are limited to the initial wound site and do not extend into the surrounding normal tissues. They resemble keloids in earlier stages but tend to flatten out in later stages - a feature not shared by keloid. Microscopically, hypertrophic scars show greater number of myofibroblasts and lack thick, glassy collagen bundles (as shown in this image) as well as mucoid matrix.

Collagenoma: These appear as discrete, small, multiple, skin-colored nodules on the trunk and upper extremities during post-pubertal period. There is no history of trauma. Microscopically, they consists of fibrocollagenous nodules in the dermis that resemble hypertrophic scar or keloid. (continued in the next image)