Keloid and Cellular Scar

 Superficial telangiectatic vessels often present

image May be associated with mild chronic inflammation

• Increased fibroblasts, lymphocytes, and mast cells usually present

Top Differential Diagnoses

• Hypertrophic scar
image Lacks characteristic hyalinized collagen bundles of keloid

• Nodular fasciitis
image May rarely show focal keloidal collagen but should have background of typical loose stroma

• Desmoplastic melanoma
image Rarely may enter differential diagnosis if no history of trauma or previous biopsy/surgery

• Dermatofibroma

• Keloidal atypical fibroxanthoma

Clinical Photograph of Multiple Keloids
Clinical photograph shows multiple keloids on the shoulder and upper arm of this patient.

Scanning Magnification of Keloid
Scanning magnification of a keloid shows a polypoid skin lesion with dense dermal collagen. Note the mild epidermal hyperplasia and telangiectatic vessels image.

High Magnification of Keloidal Collagen
High-power examination of a keloid shows a proliferation of thickened, hyalinized eosinophilic collagen bundles with increased numbers of stromal fibroblasts. Collagen bundles are randomly oriented and unevenly distributed.

Keloid With Telangiectasia
Superficial portion of keloid shows telangiectatic vessels image surrounded by thickened collagen bundles.



• Scar with keloidal collagen


• Scar with prominent thickened and eosinophilic bundles of collagen extending beyond original wound


Unknown, Possibly Genetic

• Fibroblasts from keloids show decreased apoptosis

• Many cytokines implicated in stimulating fibroblasts, including TGF-β, heat shock proteins, and IL-15



• Age
image Most common in patients < 30 yr

• Ethnicity
image More common in patients of African lineage; least common in Caucasians


• Earlobe is most common site
image Typically follows ear piercing or other trauma


Apr 24, 2017 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Keloid and Cellular Scar

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