Histomorphometric analysis of collagen architecture of auricular keloids in an Asian population.
BACKGROUND
Keloids are a pathologic condition of the reparative process, which present as excessive scar formation that involves various cells and cytokines. Many studies focusing on the histologic feature of keloids, however, have shown discordant results without consideration of architectural aspect of collagen structure.


OBJECTIVE
The purpose of this study was to demonstrate a schematic illustration of collagen architecture of keloids, specifically auricular keloids, and to analyze each part on the histomorphologic and morphometric basis.


METHODS
Thirty-nine surgically excised auricular keloids were retrieved from the file of Kangbuk Samsung Hospital. After exhaustive histomorphologic analysis, 3 distinctive structural parts, keloidal collagen, organizing collagen, and proliferating core collagen, were identified and mapped in every case. Cellularity of fibroblasts, blood vessel density, degree of inflammatory cell infiltration, and mast cells counts using Masson trichrome stain, Van Gieson stain, toluidine blue stain, and immunohistochemical stains for CD31 and smooth muscle actin were analyzed in each part of each case. Morphometric analysis on these parameters using ImageJ software was performed using 3 representative images of each part.


RESULTS
Three parts were histomorphologically distinct by shape and array of collagen bundles, fibroblasts cellularity, blood vessel density, degree of inflammatory cells, and mast cell infiltration. Morphometric analysis revealed statistically significant difference between each part in fibroblasts cellularity, blood vessel density, degree of inflammatory cell infiltration, and mast cells count. All parameters were exceedingly high in whorling hypercellular fibrous nodules in proliferating core collagen showing simultaneous changes in other parts.


CONCLUSIONS
Morphologically and morphometrically, 3 distinctive parts were identified in auricular keloids. Mast cell infiltrations, blood vessel density, and fibroblast cellularity are simultaneously increased or decreased according to these parts. Proliferating core collagen might serve as a proliferating center of keloids and might be a key portion for tumor growth and recurrence.
*Department of Pathology, The Catholic University of Korea, Yeouido St Mary's Hospital, Seoul, South Korea; †Buleun Health Care Center, Incheon, Republic of Korea; ‡Department of Plastic and Reconstructive Surgery, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, South Korea.
Yosep
Y
Chong
Tae Hwan
TH
Park
Sang won
Sw
Seo
Choong Hyun
CH
Chang
D000293:Adolescent; D000328:Adult; D044466:Asian People; D002449:Cell Aggregation; D002452:Cell Count; D015331:Cohort Studies; D003094:Collagen; D054644:Ear Auricle; D005260:Female; D005347:Fibroblasts; D006801:Humans; D007627:Keloid / Q000208:ethnology* / Q000473:pathology* / Q000601:surgery; D008297:Male; D008407:Mast Cells; D008875:Middle Aged; D056910:Republic of Korea; D055815:Young Adult
D003094:Collagen