History and admission findings: An 85-year-old woman was admitted because of frequent syncopes. She also reported slight weight loss, cough and dyspnoea. Chest auscultation revealed slight stridor and a cardiac arrhythmia, with an irregular ventricular rate between 120 and 140 beats/min.
Investigations: She had a thrombocytopenia (96 platelets/nl), and the ECG and long-term monitoring showed a tachyarrhythmia with atrial fibrillation, a bifascicular block (left anterior hemiblock and right bundle branch block), as well typical signs of sick-sinus syndrome with short periods of bradycardic sinus rhythm and pauses of up to 6 s on rhythm change. Echocardiography indicated moderately reduced left ventricular function. Chest radiogram revealed tracheal narrowing by a retrosternal goitre. No evidence of tumour was found on bronchoscopy.
Diagnosis, treatment and course: A VVI pacemaker was implanted. When the platelet count dropped to 30/nl idiopathic thrombocytopenic purpura was suspected, but administration of high doses of corticoids and immunoglobulin was without effect. Another echocardiogram, performed because of chest pain suspicious of pulmonary embolism, revealed a large bowl-shaped right ventricular thrombus with floating parts. Demonstration of anticardiolipin antibodies established the diagnosis of antiphospholipid syndrome (APLS), thought to be secondary to thyroid cancer suspected from the computed tomography. The patient died 2 months later from recurrent pulmonary embolism and progressive liver failure. Autopsy revealed a not previously diagnosed tracheal carcinoma with metastases to the thyroid, as well as haematogenous metastatic foci within the right ventricular thrombus.
Interpretation: In case of thrombocytopenia of uncertain aetiology APLS should be included in the differential diagnosis, even in the absence of any early or acute thrombosis. If anticardiolipin antibodies and/or lupus anticoagulant are demonstrated, malignant neoplasm should be considered in addition to autoimmune disease.