Keloid: A case report and review of pathophysiology and differences between keloid and hypertrophic scars
A 26-year-old female complains of swelling on right ear lobe since 3 years. Patient had got her ear pierced when she was 3 years old and had not developed any swelling following piercing. Additional ear piercing was done at the age of 23 years, which was 1 cm above the previous site, subsequent to which patient developed swelling, which continued to grow until it reached to the present size. The swelling was firm, non-tender, dumbell-shaped, measuring 3 cm in diameter, present medial to the inferior part of the helix []. A clinical diagnosis of keloid or an irritational fibroma was given.\nKeloid was surgically excised after obtaining informed consent from the patient. Histopathological sections showed hyperorthokeratinized stratified squamous epithelium and superficial dermis showed fibroblastic cells arranged parallel to epidermal surface with diffuse chronic inflammatory cells. Mild to deep dermal sclerosis showing large dense bundle of glassy collagen, was characteristically seen. A final diagnosis of Keloid was given [].\nSpecial stain like Van Gieson's was used to identify collagen bundles. Van Gieson's stained slide showed yellow colored epidermis and thick collagen bundles stained red in the dermis. Under polarized light, collagen bundles showed reddish to orange birefringence indicating thick fibers []. The sections were also subjected to immunohistochemical markers such as α-SMA (alpha smooth muscle actin), desmin, and S-100. The presence of brown colored end products at the site of target antigen was considered as positive. Expression of α-SMA was seen in myofibroblasts, blood vessels and fine collagen fibers. Scattered diffuse staining of S-100 was seen and expression of desmin was negative []. Follow-up of patient after 1 year showed no evidence of recurrence.