Pericardial metastasis from adenocarcinoma of unknown origin.

Clinical History

Chronic dyspnea worsening during the last 2 days. Pericardial sheets thickening with effusion.

Imaging Findings

Chronic dyspnea, worsening during the last 2 days. Ultrasound: important pericardial effusion. Evacuative pericardiocentesis: trasudative liquid without inflammatory or tumoural cells. Plain chest film and CT evaluation was part of the diagnostic work up (Fig. 1, 2, 3, 4). Patient died three days after hospital admission. Pathology: constrictive infiltration of the visceral and parietal pericardial sheets (Fig. 5), mediastinal lymphoadenopaties and no other evidences. Cardiac tamponade was the cause of death.

Discussion

In this case, ultrasound was effective to identify pericardial effusion which was indirectly confirmed by chest plain film (Fig.1), revealing a clear enlargement of the heart profiles. Anyway, ultrasound did not add any adjunctive diagnostic elements to the case. Plain chest film revealed signs of pulmonary veins hypertension. CT (Fig. 2, 3, 4) revealed mediastinal lymphoadenopathies, pleural and pericardial effusion and pericardial sheets diffuse thickening, which were not evident in chest plain film, suggesting two principal differential diagnoses: simple or constrictive pericarditis and primary or metastatic pericardial neoplasms. On CT simple pericarditis can reveal as pericardial sheets thickening superior to 5 mm, with pericardial effusion and without evidence of solid mass. Constrictive pericarditisis is characterized by great veins dilatation and pericardial sheets thickening with calcifications, which were not present in this case. Demonstration of lymphonodes together with diffuse thickening of pericardial layers on CT suggest a tumour diagnosis in this case. Pericardial primary tumours are mesothelioma and sarcomas while the most frequent neoplasms which can metastatize to pericardial sheets are lymphomas, leukemias, melanomas and breast, gastrointestinal and lung carcinomas. The specific teaching point of the case is that differential diagnosis between primary pericardial tumours (mesothelioma or sarcoma) and pericardial metastases, which may reveal both as pericardial sheets thickening or as single or multiple nodules with pericardial effusion, is often impossible on CT as in this case. The pericardial effusion is more frequent in pericardial primary tumours, but as seen here, it can be observed also in metastatic tumours. Only autoptic and hystopathologic evaluation allows the correct final diagnosis. Primary tumour was not found also on autoptic evaluation.

Differential Diagnosis List

Final Diagnosis

Pericardial metastasis from adenocarcinoma of unknown origin.

URL:	https://eurorad.org/case/232
DOI:	10.1594/EURORAD/CASE.232
ISSN:	1563-4086