Malignant transformation of anorectal giant condyloma acuminatum (Buschke-Loewenstein tumor).

Giant condyloma acuminatum, originally described by Buschke and Loewenstein in 1925 as a lesion of the penis, is more rarely seen in the anorectum and is characterized by clinical malignancy in the face of histologic benignity; however, malignant transformation to frankly invasive squamous-cell carcinoma has been described. Malignant transformation has been reported in 15 patients with "ordinary" condylomata acuminata as well. Twenty giant condylomata acuminata have been previously reported, six of which (30 percent) went on to develop squamous-cell carcinoma. The authors report eight cases of giant condylomata acuminata with invasive squamous-cell carcinoma developing in four patients. Light and electron microscopic methods were used to verify the diagnosis of squamous-cell carcinoma and/or giant condyloma acuminatum in our cases. Human papillomavirus (HPV), known to cause condylomata acuminata, is also known to induce these tumors. The authors support the hypothesis that giant condyloma acuminatum represents an intermediate lesion in a pathologic continuum from condyloma acuminatum to squamous-cell carcinoma. These lesions have a propensity for recurrence, likelihood of malignant transformation, and significant mortality. Therefore, early and radical local excision, and in cases of recurrence, invasion, or malignant transformation, abdominoperineal resection, along with vigilant follow-up, provides the only current hope for cure.