A Comparison of Vertical and Transverse Sections in the Histological Diagnosis of Alopecia Areata Scalp Biopsy Specimens.

CONTEXT: Both vertical and transverse sections are used for the diagnosis of alopecia areata. However when a single biopsy is submitted the pathologist has to decide which type is better.

AIMS: To compare the diagnostic histological features in vertical and transverse sections in alopecia areata scalp biopsy specimens.

SETTINGS AND DESIGN: Tertiary Care Hospital. Comparative Study.

MATERIALS AND METHODS: A total of 30 patients were enrolled in the study. Two four mm punch biopsy were taken. One was used to take vertical sections and the other for transverse section and histological features of alopecia areata noted in both.

STATISTICAL ANALYSIS USED: Chi-square test, percentage.

RESULTS: Diagnosis of alopecia areata could be made in 30 (100%) cases in transverse sections and 28 cases (93.3%) in vertical sections. The number of hair follicles available for evaluation was more in the transverse section. Nanogen follicles and miniaturization of follicles were better visualized in the transverse sections. However the catagen and telogen follicles were noted in both vertical and transverse sections but the number and the ratio of anagen and telogen hair follicles could be better assessed in the transverse sections. Presence of peribulbar lymphocytic infiltrate, eosinophils and pigment casts were noted in both transverse and vertical sections.

CONCLUSIONS: Transverse sections provide a better assessment of the histological features of alopecia areata than vertical sections and thus should be preferred.