A large fungating verruciform xanthoma of the scrotum in association with arteriovenous malformation mimicking giant condyloma

A 97-year-old man with underlying hypertension and benign prostate hyperplasia, had a large tumor on the right side of his scrotum for decades, during which time the tumor gradually enlarged. Easy bleeding upon irritation was recently noted, which prompted him to seek medical help. Physical examination revealed a 5 cm 3 cm 3.4 cm, pinkish fungating tumor, with a warty surface and focal hemorrhagic crust. Engorged blood vessels were noted near the stalk (Figure 1). Sonography showed hypervascularity. Projectile bleeding from the stalk base was noted during tumor excision. Histopathological examination revealed a large, exophytic fungating tumor consisting of numerous individual fibroepithelial polyp-like structures (Figure 2A). The epidermis showed acanthosis, relatively uniform elongation of thin rete ridges, and spongiosis with infiltration of neutrophils, but without granular layer or hyperkeratosis (Figure 2B). There was no koilocytosis or keratinocytic atypia. The connective tissue core showed marked edema, many dilated blood vessels, and a variable amount of inflammatory infiltrate consisting of abundant plasma cells, some small lymphocytes, and numerous histiocytes with abundant, pale foamy cytoplasm, which are CD68-positive (Figure 2C). The stalk of the lesion contained many dilated or congested large blood vessels, some of which had an uneven thickness in their walls (Figure 2D). Based on these findings, a diagnosis of fungating verruciform xanthoma (VX) in association with arteriovenous malformation was made. No recurrence was observed at the 6-month follow-up. VX is an uncommon type of mucocutaneous lesion, mostly affecting the oral cavity. Cutaneous involvement is rare, and usually presents as a pink to orange nodule or plaque, with a warty surface primarily affecting the anogenital area. The rate of scrotal involvement is higher in Japanese than in Western populations.1 The main histopathological features are epidermal hyperplasia without keratinocytic atypia or viral inclusion body and numerous foamy or xanthomatous cells in the accentuated papillary dermis. The exophytic lesion frequently shows hyperor parakeratosis and neutrophilic exocytosis. The foamy cells are positive for CD68 and weakly positive for factor XIIIa, but not S-100 protein, thus supporting that these foamy cells are histiocytes of macrophage/monocyte or dermal dendrocyte lineage.2 The inflammatory infiltrate also contains plasma cells and lymphocytes. The reticular dermis typically shows vascular ectasia, but does not have xanthomatous cells, which is different from lipidemic xanthoma. The etiology of VX remains elusive. Since it has been reported to be associated with many inflammatory and neoplastic conditions,