[Polypoid pseudosarcoma of the tongue].

Polypoid pseudosarcoma (PP) is a rare type of squamous-cell carcinoma of mouth, fauces and larynx with sarcoma-like reaction. Clinically PP is characterized by large pedunculated or sessile masses of rapid growing. This tumour recurs easily but rarely provokes metastasis. A case of polypoid pseudosarcoma of the tongue is reported. Differential diagnosis with spindle-cell carcinoma can be made following the criteria: a) the frequency and the sarcomatous appearance of the metastasis in the spindle-cell carcinoma, while PP rarely provokes metastasis which have a squamous-cell pattern; b) the gradual transition within the epithelial and the sarcomatous aspects in the spindle-cell carcinoma, not present in PP; and c) the presence of tonofilaments and desmosomes in the sarcomatous cells of the spindle-cell carcinoma, which lack in the sarcoma-like masses of PP.