Buschke-Lowenstein tumor, or giant condyloma acuminatum, is a rare, slow-growing tumor occurring in the anogenital area. It is a version of verrucous carcinoma. It is destructive and invasive locally but does not become metastatic.
Buschke-Lowenstein tumor is also called giant condyloma acuminatum or giant condyloma of Buschke and Lowenstein. The tumor generally appears in the anogenital region, mostly on the penis, but it can be localized in the perianal area, or be found on the scrotum, perineum, vulva, vagina or bladder. A case of its occurrence in the urethra with the bladder unaffected has also been described in a female patient . Some authors regard it a version of wart-like, verrucous carcinoma, which is itself a variant of squamous cell carcinoma. Others  consider it an intermediate between condyloma acuminatum (genital warts caused by human papillomavirus) and squamous-cell carcinoma.
Its appearance is usually described as a cauliflower-like, exophytic growth, although it infiltrates local tissues and therefore sometimes shows exo-endophytic growth pattern . It is a slow growing tumor, but if not treated, can grow to a large size and ulcerate the penis; if it involves the perianal region, it can cause bleeding and abscesses. Growth may be faster in immunocompromised patients.
The appearance of the tumor may suggest an aggressive nature; however, the histologic pattern is benign . Nevertheless, the tumor needs careful attention because of its large size and the high probability of recurrence  . There is also a marked tendency for malignant transformation to squamous cell carcinoma    , although metastases are very infrequent. Thus, removal of the Buschke-Lowenstein tumor is regarded as imperative to avoid the above risks . Regular follow-up is also necessary.
Several investigators have reported an association between the presence of human papillomavirus (HPV) types 6 and 11, which have a low potential for malignant transformation, and Buschke-Lowenstein tumor    . Some investigators believe the association may indicate a causal relationship , others regard this as unsubstantiated , yet others suggest possible roles for coinfecting HPV viruses 16 and 18 which have higher oncogenic potential . Thus, the role of HPV in Buschke-Lowenstein tumor has not been resolved.
A biopsy is essential for diagnosis. The biopsy must be wide and deep to allow for finding possible squamous cell carcinoma foci and to assess the extent of infiltration into an underlying tissue. The base of the tumor displays blunt-shaped tumor cell aggregates that extend deeply into the dermis. It is this deep endophytic growth and the thick stratum corneum that distinguishes the Buschke-Lowenstein tumor (BLT) from condyloma acuminatum. Vacuole formation occurs in both diseases .
Further characteristics of BLT are hyperkeratosis, parakeratosis, papillomatosis, acanthosis, and koilocytosis. The tumor may show infiltration by lymphocytes . Displacement of tissues by the tumor is also a frequent feature of BLT. Most of these traits also occur in verrucous carcinoma; thus, distinguishing BLT from verrucous carcinoma is difficult . Magnetic resonance imaging using gadolinium-diethylenetriamine pentaacetic acid (DTPA) contrast is helpful in establishing the boundaries of the tumor. Computed tomography scan has been used to examine local invasion by BLT .
Sentinel lymph node biopsy should be performed if there is a need for its examination. Human papillomavirus has been identified by in situ hybridization, polymerase chain reaction and restriction fragment length polymorphism    .