Two Unusual Cases of Giant Cell Myocarditis Associated with Mitral Stenosis and with Wegener's Syndrome.

Inflammation of the myocardium may occur in association with a wide variety of clinical conditions and occasionally occurs as an apparently isolated disorder without demonstrable cause. In some cases of isolated myocarditis, giant cells form part of the inflammatory reaction and the lesion has then been described as "isolated giant cell myocarditis." Giant cell myocardial lesions may occur, of course, in conditions like tuberculosis and sarcoidosis (Saphir, 1960; Forbes and Usher, 1962), which are regularly associated with a giant cell inflammatory reaction. In this paper, two patients with giant cell myocarditis are described. Though they are unrelated Ltiologically, both have features of special interest. The first is unusual in that the malady was diagnosed during life from examination of the left atrial appendage removed at mitral valvotomy. Thus an opportunity to correlate, simultaneously, clinical and pathological observations on proven myocarditis was presented. In the second, giant cell granulomatous myocardial lesions were found at necropsy in a patient who suffered from Wegener's syndrome, a disorder in which granulomatous lesions in the respiratory tract and elsewhere are associated with vascular lesions of polyarteritis type and glomerulitis. Some authors including Wegener himself suggest that this syndrome is a variant of polyarteritis nodosa rather than a separate disease (Wegener, 1939; Harrison, 1960; Heptinstall, 1960). Though cardiac lesions have been described in this illness (Levine and Madden, 1957; Walton, 1958) the chapter written by Saphir (1960) in Gould's Pathology of the Heart does not include Wegener's syndrome in an extensive survey of clinical conditions associated with myocarditis.