Dear Editor, Thymomas are located in the normal location of the thymus, the anterior mediastinum. It is very rare for thymomas to arise primarily intrapericardialy.1,2 A survey of the literature reveals that only a few reports on these tumours are available.1,3 While the most common complication of orthotopic thymoma is myasthenia gravis a paraneoplastic syndrome, patients with pericardial tumour manifestations often present with symptoms of impeded cardiac function.4 We present a case of thymoma involving the pericardium. The tumour was an entirely intrapericardial thymoma. According to the death certificate, the patient had lost consciousness during the night and was taken to a hospital emergency department where she was treated. However, she died on the same day. The death was considered of a suspicious nature and an autopsy was mandated by the prosecutor. Her family members reported that she had had occasional episodes of chest pain, fatigue, and that she had been diagnosed with a postpartum anxiety disorder. The primary location of the thymoma had not been clearly established by postpartum radiograms, and no abnormal mediastinal profiles had been noted. Analgaesic treatment had been administered. She had no myasthenia-like symptoms, weight loss, night sweats, pruritus or lymphadenopathy. The patient was 23 years old, 169 cm in height and weighed 60 kg. On investigation, defibrillator marks on the thoracic wall and needle puncture sites on the back of the right hand and the cubital fossas were detected. The autopsy revealed a massively thickened pericardium, and a huge mediastinal mass. The tumour was encapsulated measuring 10 x 4 x 3 cm (Fig. 1). It showed a lobulated pink-tan cut surface. Areas of necrosis and haemorrhage were also noted. Macroscopic examination of both lungs revealed subpleural superficial bleeding areas between the lobes; histopathological examination showed oedema and congestion. The brain appeared normal on histopathological examination. The heart weighed 320 g. Tissues had been routinely fixed in 10% buffered formaldehyde, embedded in paraffin and subsequently stained with haematoxylin-eosin. Histologic sections showed a cellular tumour with a prominent lobular pattern under low-power microscopy. The lesions showed dense lymphoid tissue with a lobular configuration, sharply separated by thick collagenous septa arising from the capsule. With higher magnification, polygonal epithelioid cells admixed with Pericardial Thymoma: An Unusual Cause of Sudden Death†