Scarring alopecia and the dermatopathologist

Area of Science:

• Dermatopathology
• Trichology
• Histopathology

Background:

• Cicatricial alopecia diagnosis is challenging for dermatopathologists due to limited training in scalp biopsy interpretation.
• Accurate assessment requires qualitative and quantitative data from scalp biopsy specimens, often best obtained from transverse sections.
• Clinical correlation, including patient demographics and hair loss patterns, is crucial for accurate diagnosis.

Purpose of the Study:

• To review the histologic features of five common forms of cicatricial alopecia.
• To provide dermatopathologists with a diagnostic checklist for scalp biopsy specimens.
• To highlight the challenges in definitively classifying cicatricial alopecia due to overlapping features.

Main Methods:

• Review of histologic features of five distinct forms of cicatricial alopecia.
• Development of a diagnostic checklist for cataloging features in scalp biopsy specimens.
• Analysis of clinical and histologic overlap between different cicatricial alopecia subtypes.

Main Results:

• Five distinctive forms of cicatricial alopecia were identified: chronic cutaneous lupus erythematosus, lichen planopilaris, dissecting cellulitis, acne keloidalis, and central centrifugal scarring alopecia.
• A checklist approach aids in cataloging diagnostic features from scalp biopsy specimens.
• Histologic and clinical overlap exists between cicatricial alopecia forms, complicating definitive classification.

Conclusions:

• Histologic review and a diagnostic checklist can assist in identifying cicatricial alopecia.
• Definitive diagnosis is not always achievable due to significant overlap in clinical and histologic features.
• An "cicatricial alopecia, unclassified" category may be necessary for ambiguous cases.