Development of valvular lesions in metastatic carcinoid disease.

In recent years there has been a great deal of interest in the so-called carcinoid syndrome. This syndrome has been observed in many cases of carcinoid tumour of the gastro-intestinal tract with extensive metastasis. It consists of certain transient and permanent vaso-motor changes, bronchoconstriction, hyperperistalsis, oedema and ascites, pellagra, and mural and valvular endocardial sclerosis with symptoms and signs of pulmonary and/or tricuspid heart disease. In most reported cases, only some of these components have been evident. It is generally believed that most of the signs and lesions are caused by 5-hydroxy-tryptamine released from the tumour tissue, but the exact mechanisms behind the changes are insufficiently known. The development of endocardial sclerosis in the right side of the heart is especially difficult to explain: though several explanations have been offered, no valid proof has been published in support of any of them. All recent authors agree that the endocardial lesions are acquired late in the course of the tumour disease. However, only a few of the reported patients have been studied before and after the development of their valvular lesions and for this reason the authors believe the present case to be of interest. Our studies include right-heart catheterization during a spontaneous flush episode and verification of the lesions by autopsy. The early history of this patient and some of the haemodynamic studies have been published (Thorson et al., 1954; Waldenstrom and Ljungberg, 1955; and Thorson, 1956).