Extranodal head and neck non-Hodgkin's lymphomas in children in Finland.

During the 20-year period from 1961 to 1980, 17 cases of extranodal head and neck non-Hodgkin's lymphoma in children under 15 years of age were diagnosed in Finland. Eight cases had tumours in tonsils or nasopharyngeal adenoids and 9 cases lymphomas of other sites of the head and neck. The age-adjusted annual incidence rate for all cases was 0.69 and for tumours of the pharyngeal lymphatic tissue 0.35 per 10(6) children. Seven of the 17 tumours were undifferentiated lymphomas (Burkitt's and non-Burkitt's types) and 5 lymphoblastic lymphomas. The overall 5-year disease-free survival rate was 37%. Five of the 9 patients with tonsillar or adenoid lymphomas were disease-free more than 5 years.