Verruciform xanthoma in an adolescent: a case report

BACKGROUND

Verruciform xanthoma is a benign mucocutaneous, verrucous, papillary lesion characterized by large foam cells in the parakeratotic layer, lipid-laden macrophages (xanthoma cells), epidermal hyperplasia, and hyperkeratosis. Verruciform xanthoma is thought to be a reactive rather than a neoplastic process secondary to epithelial damage and the presence of foamy histiocytes. The human papillomavirus has not been proven to be a causative factor. Differential diagnoses include verrucous carcinoma, condyloma acuminatum, seborrheic keratosis, verruca simplex, and vulvar intraepithelial neoplasia.

CASE

We describe the clinical and pathologic findings of a 16-year-old girl with verruciform xanthoma of the vulva, the third such reported case in an adolescent girl.

COMMENT

It is important to recognize this rare entity because it can mimic many other conditions, and the usual treatment modalities for wartlike growths on the vulva (i.e., imiquimod, podophyllin, and trichloroacetic acid) are not effective. Wide local excision seems to be the only effective and curative treatment modality for verruciform xanthoma, as has been reported in the literature and is such with our case.

Verruciform xanthoma-like phenomenon in seborrheic keratosis

Verruciform xanthoma is xanthomatous dermal infiltrate in a proliferating epidermal lesion and is an uncommon phenomenon. It has been reported in various neoplastic or inflammatory conditions. We report a 72-year-old man who had an asymptomatic 1-cm black nodule on his abdomen. Histopathology showed a typical acanthotic type of seborrheic keratosis characterized by basaloid keratinocyte proliferation and pseudohorn cysts. Many aggregated xanthomatized cells were seen in dermal papillae within the acanthotic epithelium. Papillomatosis, parakeratosis, and neutrophil infiltrates, the histologic features of typical verruciform xanthoma, were not seen. The foamy cells were positive for CD-68 and vimentin and negative for cytokeratin and S-100. No human papillomavirus DNA was found by nested polymerase chain reaction. The blood lipid profile was normal. The presence of verruciform xanthomatous change in seborrheic keratosis provides further evidence that verruciform xanthoma may be a reactive phenomenon occurring in common skin disorders.

Verruciform xanthoma of the oral cavity: clinicopathological study relating to pathogenesis. Report of three cases

Verruciform xanthoma is a rare condition that was first reported in the oral cavity in 1971. Its histopathology is distinctive on account of the presence of foamy histiocytes within elongated dermal papillae. Three cases of oral mucosal verruciform xanthoma were studied. Immunohistochemical staining by streptavidin-peroxidase and in situ hybridization to detect human papillomavirus (HPV types 6, 11, 16, 18) DNA and matrix metalloproteinase (MMP-2, -9) RNA were performed to investigate the pathogenesis of verruciform xanthoma. This study showed that the foam cells were strongly positive for CD68 (KP1) and vimentin. Cytokeratin, PCNA and S-100 stained focally negative in foam cells. In situ hybridization failed to detect HPV (types 6, 11, 16, 18) in any of the three cases. Based on our findings we conclude that verruciform xanthoma is most likely not a human papillomavirus-associated lesion; the foam cells, as a histological hallmark of the lesion, are most likely derived from the monocyte-macrophage lineage, and verruciform xanthoma is, at least partly, mediated by an immune mechanism. MMPs degrade basilar membrane that promotes the reciprocal induction between epithelium and mesenchyme. However, as yet unrecognized factors may play a role in the development of epithelium-mesenchyme reciprocal induction.