Differential diagnosis of verrucous carcinoma in the oral cavity and larynx.

Two cases of local metastasing verrucous carcinoma (oral cavity and larynx) are presented. Difficulties in the histological diagnosis are demonstrated. Histological criteria of verrucous carcinoma are discussed in comparison to leucoplakia, papilloma, pseudoepitheliomatous hyperplasia, verrucous hyperplasia, and highly differentiated squamous cell carcinoma (grade 1). The importance of correct diagnosis for further diagnostic and therapeutic procedures is pointed out.