Irradiation-induced tumours of the head and neck.

Though irradiation-induced tumours are uncommon they represent a well defined entity. At this Hospital, 14 "irradiation-induced" head and neck tumours were encountered in 11 patients over a 10-year period. The irradiation had been given for tuberculous lymph-adenitis in 6 of the patients, for lupus vulgaris in one, and thyrotoxicosis in another; the other 3 patients had received radiotherapy for malignant tumours. The interval between the treatment and the diagnosis of the tumour disease ranged from 9 to 48 years (mean 32). The induced tumours included 10 squamous cell carcinomas of the hypopharynx (4 tumours), the buccal mucosa (3), the skin (2), and the larynx (1), one poorly differented carcinoma of the parotid gland, 2 thyroid carcinomas and 1 fibrosarcoma of the stenocleidomastoid muscle. Three of the patients had multiple tumours. In view of the risk of cancer--albeit a small one--associated with radiological diagnosis and radiotherapy, these should be performed only on strict indications, especially in young patients.