Kaposi's haemangiosarcoma of the heart.

There are numerous reports of the frequency with which Kaposi's sarcoma is encountered in the African. It is a true but atypical sarcoma, starting as a single reddish or purplish nodule on one or both lower extremities. Further nodules form slowly and spread up the limb, while at the same time the earlier lesions tend to coalesce. The condition is generally bilateral, resulting in a stocking distribution, which later spreads to the trunk, upper limbs, or viscera. The African appears to possess a peculiar predisposition to the disease, which in Europe is frequent amongst the labouring classes in Italy, where it was originally described. Women are rarely affected. Death is invariable, but the interval between the onset of the condition and death varies. Visceral manifestations usually occur from two to five years after the onset of the disease, which generally terminates fatally in three to eight years. Referring to the site of secondary deposits, Choisser and Ramsey (1939) include the respiratory tract, lymph nodes, stomach, intestines, liver, kidney, and bladder. In their review on the disease, they failed to find a case of cardiac or pericardial involvement, but were themselves able to record two European cases in which the lesions were primarily in the heart but not found in the skin: in both the disease ran a rapid downhill course, the patients dying of cardiac tymponade. Autopsy showed proliferative lesions, involving primarily the right atrum with spread to the myocardium, pericardium, diaphragm, and mediastinum, and isolated lesions in the liver and lungs. A closer study of reported cases revealed eight heart tumours variously diagnosed, in which they regarded the microscopical picture as identical with Kaposi's sarcoma although, as they stated in their review of cases reported as such, they had been unable to find a single instance in which the condition was primary in the heart. The pathology of the disease is of interest. The tumour is composed of small newly formed blood vessels, with walls composed only of cells resting on a reticular base. In other places the blood sinuses are full of blood or debris. Small foci of polymorphonuclear leucocytes and lymphocytic infiltration are usually also present. As well as the blood vessels there are more solid portions of the tumour consisting of proliferative embryonic spindle cells differing in size, shape, and arrangement: some are small, others large, and all possess hyperchromatic nuclei with only an occasional mitotic figure. The structure of the tumour varies in different portions as does the pleomorphism in individual regions, but the important feature to be noticed is its vascularity.