Adenoid cystic carcinoma of the head and neck. Controllable and uncontrollable factors in treatment and prognosis.

Histological re-examination of 64 adenoid cystic carcinomata showed that 15 of them were different tumours, mainly adenocarcinomata. The remaining 40 adenoid cystic carcinomata were solid in 6 cases, cribriform in 24 cases and tubular in 14 cases. No precise classification was possible in 5 cases of adenoid cystic carcinoma. Uncontrollable factors important for the prognosis of adenoid cystic carcinomata included the histological type and the site of the tumour: major salivary glands (28 cases), area of paranasal sinuses (11 cases) and minor salivary glands (10 cases). Adenoid cystic carcinomata of tubular type or situated in minor salivary glands had a relatively favourable prognosis related to survival rate, 'state of health' and tendency to recurrence. Controllable factors exerted a favourable influence on the commonly poor prognosis of adenoid cystic carcinomata. They included an early diagnosis and, because of the tendency to recurrence, radical surgery and radiotherapy. The poor long-term prognosis of this tumour was due to a tendency to local recurrence (80% of cases) and mainly haematogenous metastasis (37% of cases). Lymphogenous metastasis was less frequent (6% of cases).