Diagnosing And Treating Verrucous Carcinoma In The Lower Extremity

Verrucous carcinoma is a low-grade, well-differentiated, warty-like squamous cell tumor.¹ Although rare in occurrence, verrucous carcinomas are locally aggressive and destructive. These lesions are typically slow growing with a low proclivity for metastases. Even if a verrucous carcinoma has been present for many years with penetration to the underlying bone, distant metastases remain rare.²

In the lower extremity, verrucous carcinomas are most frequent on the plantar aspect of the foot and are called carcinoma cuniculatum or epithelioma cuniculatum.^1,3 Epithelioma cuniculatum most often occurs in older males with a mean age of 52 to 60 years.² These initially present with striking resemblance to verruca vulgaris. Over time, the tumor develops its characteristic large, exophytic, cauliflower-like growths. Pressure can often expel a collection of foul-smelling, greasy sebaceous material and keratotic detritus from these lesions.^2,3

Epithelioma cuniculatum has been associated with several strains of the human papillomavirus (HPV) with oncogenic potential, including HPV 16 and 18. Unfortunately, the exact pathogenesis of verrucous carcinoma remains unclear and more studies are needed in this area.²

Treatment of these tumors begins with proper diagnosis. Treatment is often delayed due to the resemblance of verrucous carcinoma to verruca vulgaris.² One should remain suspicious of any lesion on the sole of the foot or elsewhere on the lower extremity that has been present for an extended period of time, is growing in size, and/or has failed previous attempts at treatment for verruca vulgaris. If the clinician is at all concerned that the lesion in question may be verrucous carcinoma, a punch or shave biopsy may facilitate a histological diagnosis.

Upon the diagnosis of epithelioma cuniculatum, one may perform wide excision of the tumor. Excisional surgery remains dependent on the location and size of the tumor. One may also utilize secondary and delayed closures along with skin flaps and grafts. Finally, in areas where skin for closure may not be adequate, Mohs surgery may be warranted.

The photograph above demonstrates a carcinoma cuniculatum of the medial malleolus in a 73-year-old male. The lesion was non-painful, had been present for several months and recently began to increase in size rapidly. The patient presented to our office for initial treatment and I obtained a shave biopsy at this time. The biopsy confirmed the diagnosis of verrucous carcinoma. I referred the patient to a local surgical dermatologist for Mohs surgery of the lesion.

References

1. Vandeweyer E, Sales F, Deraemaecker R. Cutaneous verrucous carcinoma. Br J Plast Surg. 2001; 54(2):168-170.
2. Schwartz RA. Verrucous carcinoma of the skin and mucosa. J Am Acad Dermatol. 1995; 32(1):1-21.
3. Miller SB, Brandes BA, Mahmarian RR, Durham JR. Verrucous carcinoma of the foot: a review and report of two cases. J Foot Ankle Surg. 2001; 40(4):225-231.
4. Schell BJ, Rosen T, Rady P, et al. Verrucous carcinoma of the foot associated with human papillomavirus type 16. J Am Acad Dermatol. 2001; 45(1):49-55.