Verruciform Xanthoma

Introduction

Note: click on underlined words for more detail or photos.

The verruciform xanthoma is a papilloma look-alike lesion which seems not to be associated with HPV but is perhaps a response to local trauma. The lesion contains abundant lipid-laden histiocyte-like cells and is histopathologically similar to dermal xanthomas, although there appears to be no association with diabetes mellitus, Langerhans cell disease (histiocytosis X), hyperlipidemia, or any other metabolic disorder. Some authors have suggested that the lesion may represent an unusual reaction to localized epithelial trauma or damage. This hypothesis is supported by cases of verruciform xanthoma that have developed in association with disturbed epithelium (melanocytic nevus, epidermolysis bullosa, epithelial dysplasia, pemphigus vulgaris, etc.). First reported as an oral lesion in 1971, it has subsequently been reported on the skin and vulvar mucosa, although it remains a predominantly oral lesion. There is some evidence for an association with immune suppression in some cases.

Clinical Features

This unique lesion occurs in middle-aged and older individuals, usually 40-70 years of age. There is a strong female predilection (1:2 male/female ratio) and the usual intraoral locations are the gingiva and alveolar mucosa, but any oral mucosal site may be involved.

The lesion appears as a well-demarcated, soft, painless, sessile, slightly elevated mass with a white, yellow/white, or red color and a papillary or roughened surface ("verruciform"=with pointed projections, warty). It is usually less than 2 cm. in diameter and no oral lesion larger than 4 cm. has been reported (Figures 1 & 2). Multiple lesions have occasionally been described. Aggregated xanthoma cells may be so numerous as to be visible clinically as a cluster of small yellow surface nodules resembling fish eggs.

Verruciform xanthoma may be very similar in clinical appearance to squamous papilloma, condyloma acuminatum, or early carcinoma, and biopsy may be the only means by which to distinguish one from the other.

Pathology and Differential Diagnosis

There is an obvious verruciform or papillary surface change, often with clefts or crypts between the epithelial projections, sometimes filled with parakeratin (Figures 3 & 4). The surface layer of parakeratin is typically thickened, and on routine hematoxylin and eosin staining exhibits a distinctive orange coloration. The rete ridges are elongated to a uniform depth.

The required histopathologic feature of verruciform xanthoma is found within the connective tissue papillae, which contain foamy histiocytes or xanthoma cells ("xanthos" = yellow). These cells are not seen beneath the level of the adjacent rete ridges and may completely fill the papilla (Figure 5). They contain lipid as well as periodic acid Schiff (PAS)-positive, diastase-resistant granules. There has been no plausible explanation for the strong localization of lesional cells in the papillae.

The pathologist must be careful not to confuse xanthoma cells with lingual dorsum taste buds in the connective tissue papillae, but differentiation from other maxillofacial lesions with foamy or granular histiocyte-like cells is not difficult because verruciform xanthoma is the only lesion to have these cells confined to the papillae. Granular cell epulis, granular cell tumor and fibrous histiocytoma all present with extensive foamy or granular histiocyte-like cells throughout the lesional stroma and, in fact, typically present with a subepithelial zone free of such cells.

Treatment and Prognosis

Verruciform xanthoma is treated by conservative surgical excision and recurrence is rare with this treatment. Although no malignant transformation has been reported, a few cases of verruciform xanthoma have been reported in association with carcinoma-in-situ or squamous cell carcinoma. This might imply that it is a potentially premalignant lesion, but is probably best explained as representing degenerative changes in response to dysplastic epithelium.

References (Chronologic Order)

Note: Click on underlined author's names for additional detail.

General references:

Neville BW, Damm DD, Allen CM, Bouquot JE. Oral and maxillofacial pathology. Philadelphia, W. B. Saunders; 1995.

Elder D, Elenitsas R, Jaworsky C, Johnson B Jr. Lever's Histopathology of the skin, 8th edition. Philadelphia; Lippincott-Raven, 1997.

Sapp JP, Eversole LR, Wysocki GP. Contemporary oral and maxillofacial pathology. Mosby; St. Louis, 1997.

Odell EW, Morgan PR. Biopsy pathology of the oral tissues. London; Chapman & hall Medical, 1998.

Specific references:

Pictures

Note: To see enlarged photo, click on the left-hand picture; 
return here with your BACK ARROW button.

		Figure 1:    [return to text]
		Figure 2:    [return to text]
		Figure 3:    [return to text]
		Figure 4:     [return to text]
		Figure 5:     [return to text]
		Figure 6:     [return to text]
		Figure 7:     [return to text]
		Figure 8:     [return to text]