Primary cicatricial alopecia: histopathologic findings do not distinguish clinical variants.

BACKGROUND: Primary cicatricial alopecias encompass a group of disorders characterized by permanent destruction of the hair follicle. The varied clinical features and differences in terminology have led to difficulties in defining consistent clinicopathologic correlation. OBJECTIVE: We sought clinicopathologic correlation of 6 clinically distinct primary cicatricial alopecias: lichen planopilaris, frontal fibrosing alopecia, pseudopelade (Brocq), central centrifugal alopecia, folliculitis decalvans, and tufted folliculitis. METHODS: We conducted prospective and blinded histopathologic evaluation of clinically typical primary cicatricial alopecias. Biopsy specimens were taken from early affected scalp lesions and paired with samples from clinically unaffected areas in the same patient. RESULTS: The lymphocytic and neutrophilic groups were readily distinguished histologically. However, within the two groups clinically distinct primary cicatricial alopecias could not be distinguished with current histopathologic techniques. CONCLUSION: A descriptive, standardized histopathologic reporting of follicular architecture, type, location, and extent of the inflammatory infiltrate, and presence or absence of sebaceous glands, may be of greatest value in guiding the treatment of patients with primary cicatricial alopecias.

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.