Pathology of the epidermal nevus

Introduction

Epidermal nevus falls into the category of benign epidermal tumors

Histology of epidermal nevus

The view of the scanning power of an epidermal nevus is from an epidermis proliferative process (Figure 1). Under power reveals hyperkeratosis and papillomatosis across the sample (Figures 2.3). Epidermal hyperplasia forms finger-shaped projections with intermediate invaginations filled with hyperkeratotic material (Figure 4). Incidental fungal spore forms are frequently observed. Extending below the projections in the dermis thickened anastomoses laces of the acanthotic epidermis (Figure 5). Dermal collagen and the telangiectatic vessels can be seen within the papillary projections (Figures 5 and 6).

A variable inflammatory infiltrators can accompany epidermal changes, more prominent in inflammation warty variant.

Histological epidermal nevus variants

There are several reported variants, including acantholyticporokeratotic acanthosis nigricans, Hailey-Hailey disease, and warty epidermal nevi.

Differential diagnosis of epidermal nevus

Inflammatory warty epidermal nevus (ILVEN): This nevus is probably simply a subtype of epidermal nevi. In addition to the superficial perivascular or lichenoid lymphocytic infiltrate Specific epidermal changes are recognized. Alternation areas parakeratosis and orthokeratosis Are seen. Under parakeratosis there is hypogranulosis, while under orthokeratosis there is hypergranulosis.

Seborrheic keratosis - Although clinical correlation is essential here, the presence of elongated descending growths of the epidermis with some flattening at the base is more in line with an epidermal nevus.