Mucin-producing adenocarcinomas and nonbacterial thrombotic endocarditis: pathogenetic role of tumor mucin.

The clinicopathologic data of 5 patients who died of nonbacterial thrombotic endocarditis (NBTE) and disseminated thrombosis and multiple infarcts associated with mucin-producing adenocarcinomas were presented. Histochemical studies on the valvular vegetations and thrombi revealed that histochemically stainable mucinous substance was an integral part. In 1 patient, circulating mucinous substance was found prior to the development of NBTE and disseminated thrombosis, and the identical mucinous substance was found in the tumor tissue, indicating a possible pathogenetic role of tumor mucin in NBTE-associated mucin-producing adenocarcinomas. Our observations and reports of others suggest that intravascular mucin may be responsible for the clinical syndromes of mucinous malignancies, venous thrombosis, and NBTE with emboli.