A 70-year-old male who has been chewing tobacco for the past 50 years presents with a six months history of a large, fungating, soft papillary lesion in the oral cavity. The lesion has penetrated into the mandible. Lymph nodes are not palpable. Two biopsies taken from the lesion proper, show benign appearing papillomatosis with hyperkeratosis and acanthosis infiltrating the subjacent tissues. The most likely diagnosis is -
Verrucous carcinomas also referred to as giant condyloma accuminatum or Buschke-Lowenstein tumor are considered an intermediate lesion between condyloma accuminatum and invasive squamous cell carcinoma. It is important to distinguish verrucous carcinoma from squamous cell carcinomas as these tend to remain localized and are cured by wide excision, however they may undergo malignant transformation into invasive squammous cell carcinomas.
Features of verrucuous carcinomas

Predilection for males > 50 years
Predisposed in tobacco users, poor oral hygiene
Squamous cell papilloma
Squamous cell carcinoma
Verrucous carcinoma
Malignant mixed tumour