ABSTRACT

Lichen planus (LP) is a chronic inflammatory and immune-mediated disease characterized by multiple clinical presentations. There are very few studies analyzing histopathological features of LP worldwide.

The aim of this work was to study different histopathological patterns in skin biopsies of LP and to correlate the clinical and histopathological features.

Records of 184 biopsies diagnosed as LP were included in the study. Clinical data from the records reviewed. Hematoxylin and eosin-stained sections were retrieved, re-examined, and histopathological parameters were noted.

Among the 184 biopsies of LP patients, pigment incontinence (93.5%) was the most common followed by hypergranulosis (88%) and interface dermatitis (82.6%). In epidermal changes, saw-toothed acanthosis (90, 48.9%) was the most common followed by the flattened epidermis (47, 25.5%), irregular moderate acanthosis with appendageal involvement (31, 16.9%), and pseudocarcinomatous hyperplasia (16, 8.7%). In tissue reaction patterns, the lichenoid pattern was the most common (131, 71.2%) followed by mild superficial perivascular dermatitis (MSPVD) in 20 (10.9%) followed by various combination patterns. The types of hypergranulosis seen were wedge-shaped (86, 53.1%) followed by infundibular (32, 19.8%), regular (30, 18.5%), and acrosyringeal (14, 8.6%). Changes of venous stasis were observed in 41% of lower limb biopsies.

On histopathology, pigment incontinence and hypergranulosis were the most consistent features in all types of LP. Awareness about the less frequent patterns may improve the diagnostic accuracy of clinicopathologic correlation.