Of 40 patients (16 males and 24 females), 29 had cardiac myxoma(s), 14 had skin pigmentation (lentigo and several types of nevi) which also commonly affected the lips, 6 had skin myxoma(s), and 12 had both pigmentation and myxoma(s); 18 had primary pigmented nodular adrenocortical disease (Cushing syndrome was present in 11); 10 had myxoid mammary fibroadenomas; 9 had testicular tumor(s) (large-cell calcifying Sertoli cell tumor, Leydig cell tumor, or adrenocortical rest tumor, or a combination); and 4 had pituitary adenoma with gigantism or acromegaly. The maximum number of conditions present together was five, occurring in two patients; each of the remaining patients had at least two of the conditions. The overlap, in this sizeable number of patients, of various combinations of the same rare or very rare conditions unlikely to occur together by chance with any degree of frequency is striking evidence for a unique syndrome. The patients were young (mean age at diagnosis of the first component, 18 years). Pathologic involvement tended to be multicentric (heart and skin) and bilateral in paired organs (adrenal, breast, and testis). Thirteen patients (32%) are alive and well. Twelve patients are alive but with complications of cardiac myxoma (in 8), testicular tumors (in 2), residual Cushing syndrome (in 1), or bilateral pulmonary nodules (in 1). Twelve patients are dead: 9 of cardiac myxoma, 1 of intracranial (nonpituitary) tumor, and 2 postoperatively. The status of three is unknown.