Papillary squamous neoplasms of the head and neck.

Papillary squamous neoplasms of the upper respiratory tract are rare variants of squamous cell carcinoma and are related temporally to proliferative verrucous leukoplakia. Fifty-two cases of papillary squamous neoplasms were selected from 2366 cases of squamous cell carcinoma. This is the first study to characterize the biological behavior of papillary squamous neoplasms. Papillary squamous neoplasms exhibit two distinct, yet sometimes overlapping, histologic patterns including an exophytic papillary and an inverting verrucous morphologic appearance. A high rate of synchronous or metachronous lesions were found, especially with the inverting-type of papillary squamous neoplasm. Stage T3 and T4 lesions had a high rate of neck metastasis. Early surgical intervention and close long-term follow-up is mandatory.