Unguioblastoma and unguioblastic fibroma--an expanded spectrum of onychomatricoma.
Onychomatricoma is a rare tumor that appears to originate from cells of the nail matrix. Three cases of onychomatricoma that met Perrin et al.'s1 histologic criteria of onychomatricoma are described. However, using a single term to classify all three tumors ignores the apparent microscopic differences that exist among them. To demonstrate better the spectrum of so-called onychomatricoma and properly acknowledge the noticeable disparity among our cases, a series of terms is proposed. This terminology is based on the histologic spectrum of epithelial-stromal ratio of stromal cellularity and of extent nuclear pleomorphism. Use of such criteria has a precedent in the classification of follicular and odontogenic fibroepithelial neoplasms. This new nomenclature includes "unguioblastoma" for tumors with a predominant epithelial component and "unguioblastic fibroma" for tumors where a cellular stroma is more prominent and characteristic. The term "atypical unguioblastic fibroma" is used to describe a third rare neoplasm, in which the cellular stroma shows nuclear pleomorphism and atypia with an increase of mitotic activity.
Dermatopathology Laboratory, University of California, Irvine, CA, USA.
Christine J
CJ
Ko
Linda
L
Shi
Ronald J
RJ
Barr
Lena
L
Mölne
Annika
A
Ternesten-Bratel
John T
JT
Headington
D000328:Adult; D014408:Biomarkers, Tumor / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism / Q000473:pathology; D005260:Female; D005350:Fibroma / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D009260:Nail Diseases / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D012878:Skin Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D017154:Stromal Cells / Q000378:metabolism / Q000473:pathology
D014408:Biomarkers, Tumor