Heterogeneity of squamous cell carcinomas of the head and neck in relationto clinicopathological variables

We analysed 32 primary, 8 recurrent and 16 metastatic squamous cell carcino mas of the head and neck by flow cytometry to assess tumoural heterogeneity . Intratumoural heterogeneity was found in 9 of 30 primary tumours (30%). A ll heterogeneous tumours had diploid and aneuploid cell lines. DNA indices were different from those of the primary tumours in 3 of the 8 recurrent le sions (38%) and in 8 of the 12 metastatic lesions (67%). The results indica te that new cell lines evolve during the process of recurrence and metastas is. The incidence of recurrence, metastasis, and heterogeneity increased wi th the size of the tumour. Histologically, there were tumours in which the degree of differentiation and mode of invasion of primary lesions were not consistent with the results of flow cytometry in both homogeneous and heter ogeneous tumours. In conclusion, multiple sampling for flow cytometric anal ysis is essential for better characterization of oral carcinomas.