RESUMEN
The case of a 43-year-old man with diabetes and alcoholism admitted to the emergency room with shock, fever, pleuritic chest pain and systemic symptoms is presented. Laboratory tests revealed anemia, leukocytosis, thrombocytopenia, high sedimentation rate and D-dimers, hypoxemia and hypocapnea. He also had sinus tachycardia, rSR' in V1 and an opacity on the periphery of the right pulmonary field. Blood and urine cultures were negative, as were serological markers. The echocardiogram showed a large mass adhering to the tricuspid valve, suggestive of myxoma. The patient underwent surgery, and anatomopathological examination of the mass showed it to be a bacterial vegetation, with no agent isolated. It is pointed out that differential diagnosis is difficult between a myxoma with systemic symptomatology associated with a possible pulmonary embolism, and tricuspid endocarditis with negative blood culture associated with a septic pulmonary embolism, which turned out to be the diagnosis in this patient.