poorly-differentiated bronchial carcinoma

The production of serotonin (5-hydroxtryptamine) and certain related metabolites by tumours associated with the clinical carcinoid syndrome has now been well established. Many of the reported cases have concerned carcinoid tumours of the intestinal tract (Thorson, 1958 ; Macfarlane, Dalgliesh, Dutton, Lennox, Nyhus, and Smith, 1956) but tumours histologically resembling carcinoids, and also apparently responsible for the carcinoid synidrome or the secretion of serotonin, have been reported from other sites. Of these, the so-called bronchial 'adenomas' are perhaps the commonest (Anlyan, Hargrove, Ruffin, Wallace, Weaver, and Kirshner, 1960; McCormack, Mclsaac, Ragde, Groves, and Effler, 1961 ; Warner and Southren, 1958; Sacks and Timme. 1961; Warner, Kirschner, and Warner, 1961 ; Williams and Celestin, 1962). Some. of these, like the cases reported by Joseph and Taylor (1960) and by Pollard, Grainger, Fleming, and Meachinm (1962), have metastasized widely, have shown a very poorly differentiated histological pattern, and, had they not been associated with the clinical features of the carcinoid syndrome, such as flushing and diarrhoea, might well have been mistaken for undifferentiated bronchial carcinomas. Case 2 of Williams and Azzopardi (1960) was in fact reported as an oat-celled carcinoma. The purpose of this paper is to describe a patient in whom a poorly-differentiated bronchial carcinoma was shown to produce 5-hydroxytryptamine (5-HT) in considerable quantity although this was not associated with the clinical manifestations of the carcinoid syndrome. This property was discovered by chance during investigations concerning the in vivo metabolism of 5-HT by lung tissue. By a further coincidence, arrangements had been made for the immediate fixation of tumour tissue at the time of operation, which allowed a detailed histological and histochemical examination of the secretory tissue. CASE REPORT