Differential and exclusive diagnosis of diseases that resemble keloids and hypertrophic scars.

Previous articles suggested the presence of various kinds of malignant tumors that resemble keloid or hypertrophic scar, including dermatofibrosarcoma protuberans, trichilemmal carcinoma, and keloidal basal cell carcinoma. Thus, we studied our cases that were diagnosed with diseases other than keloid or hypertrophic scar. From April 2003 to March 2007, we examined 378 patients self diagnosed with keloid or hypertrophic scar.We detected 4 other diseases (1.06%) in the group of patients. All tumors were benign: apocrine cystadenoma, adult-onset juvenile xanthogranuloma, mixed tumor, and chronic folliculitis. Our study led us to the conclusion that differential or exclusive diagnosis of diseases similar to keloid and hypertrophic scar is important. We found the following considerations important in the examination of keloid or hypertrophic scar: (1) biopsy should be conducted in anomalous cases because malignant disease may be the original or secondary problem, (2) steroid injection should be performed only after careful consideration because malignancy or infections may be present, (3) careful differential diagnosis is particularly challenging in African-Americans because skin and tumor color are often similar, and (4) the presence of bacterial or fungal infection should be investigated.