An 80+ year old patient presented to clinic reporting a long history of perineal lichen sclerosus along with the diagnoses of scleroderma and Sjogren’s. She presented with a pink, scaly papule on the left labia majora, which was biopsied to rule out squamous cell carcinoma.
Does this lesion represent a verruca, carcinoma, or some other entity?
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This lesion is a vulvar verruciform xanthoma.
On low power, the lesion has an exophytic, somewhat verrucous appearance; the low power cross section highlights the prominent fibrovascular cores and also a papillary architecture (verrucous carcinoma or condyloma might be initial low-power considerations). The epithelium demonstrates hyperkeratosis, acanthosis, and elongation of rete ridges (which are not specific features of this entity). A peculiar feature of this entity is wedge-shaped hyperkeratosis forming invaginating crypts deep into the acanthotic epithelium, and having a characteristic orange hue, with associated prominent neutrophilic inflammation. What cinches the diagnosis is the presence of innumerable histiocytes present within the elongate dermal papillae. These are best appreciated via a CD68 (histiocytic) immunostain. The combination of these features is diagnostic of verruciform xanthoma.
DIAGNOSIS & CASE SUMMARY:
Verruciform xanthoma is an uncommon entity which typically occurs in the oral mucosa. Vulvar verruciform xanthoma is extremely rare, with only a few dozen cases reported in the literature. In one paper describing 10 cases, the median age was 68, and the lesions all presented as asymptomatic yellow-orange verrucous plaques. The diagnosis was clinically suspected in 2 cases; other suggested diagnoses were condyloma or squamous cell carcinoma. All of the patients had an associated vulvar condition: lichen sclerosus (6 patients), lichen planus (2 patients), extramammary Paget’s disease, or radiodermatitis. The authors speculate that vulvar verruciform xanthoma might represent a reaction pattern induced by different conditions, mainly characterized by damage to the dermoepidermal junction.
The patient has been scheduled for a follow up exam six weeks post biopsy as the lesion was broadly shaved and hyfrecated at the time of biopsy. Verruciform xanthomas, while not usually considered malignant, recur frequently. With recurrence, full excision should be pursued for removal. Close followup is warranted since persistent inflammatory conditions often associated with these lesions are known to predispose patients to squamous cell carcinomas.
Reference: Arch Dermatol. 2011 Sep;147(9):1087-92. doi: 10.1001/archdermatol.2011.113. Epub 2011 May 16.
By: Dr. Mark Cleveland, MD, PhD; Dr. Doug Hansen, MD; and Dr. Betsy Wernli, MD