Verruciform Xanthoma: Clinical and Morphologic Spectrum Across Oral, Genital, and Cutaneous Sites.

Abstract

Verruciform xanthoma (VX) is an uncommon, benign epithelial lesion of the oral mucosa. While this entity can also present extraorally, including on the skin and in anogenital areas, the variation in its histologic features in extraoral sites is not yet well defined. Differences in the demographics and morphologic features of oral versus extraoral VX were assessed to help facilitate the accurate diagnosis and management of this lesion. After obtaining IRB approval, 110 cases of diagnosed VX were retrospectively collected from our institutional archives spanning from 2000 to 2022. Patient age, gender, available medical history, lesion appearance, and duration were obtained for each case. The median age was 55years (range 13-86) with a male-to-female ratio of 1.2:1. The most common oral sites, in descending order, were the palate (n = 24, 22%), buccal mucosa (n = 18, 16%), gingiva (n = 16, 15%), and tongue (n = 13, 12%). Extraoral sites comprised 9% of all lesions, including the scrotum (9), vulva (2), cheek (1), wrist (1), gluteal region (1), and abdominal wall (1). The median size for all lesions was 6.0mm, and extraoral lesions were associated with a 6.7mm larger size compared to oral lesions (B ± SE: 6.7 ± 2.5cm, p = 0.01). The lesions were most frequently pink or white in color and often described as papillary, pedunculated, verrucous, and/or exophytic. Microscopically, the presence of wedge-shaped parakeratosis, keratin projections above the epithelium/epidermis, and associated inflammation significantly differed between oral and extraoral lesions. Prominent wedge-shaped parakeratosis (p = 0.04) and keratin projections above the epithelium/epidermis (p < 0.001) were more prevalent in extraoral lesions. There was no significant link between keratin projections and epithelial atypia (p = 0.44). Familiarity with the broad morphological spectrum of VX, including the presence and degree of wedge-shaped parakeratosis, keratin projections above the epithelium/epidermis, and associated underlying inflammation, will be helpful in diagnosing it in unusual locations.