chylopericardium is a rare clinical entity that is characterized by the presence of chyle in the pericardial cavity . its association with lymphangiomas , cystic hygromas , thoracic and cardiac surgery , trauma , radiation and malignancy is well reported [ 2 , 3 ] . however , primary chylopericardium , in which there is absence of known precipitating factors , is rarely encountered in clinical practice . the severity of clinical manifestations of chylopericardium is varied and may range from the complete absence of symptoms to cardiac tamponade , and thus a high index of suspicion is required for the prompt recognition of the underlying diagnosis and management of its sequalae . in this report , we present a case of chylopericardium in a 23-year - old woman , presenting with acute shortness of breath in the background of extensive neck vein and superior vena cava ( svc ) thrombosis , of unknown aetiology . she had been admitted into hospital 2 weeks earlier due to a community acquired pneumonia with parapneumonic collection , which required drainage and intravenous antibiotics . her initial recovery was uneventful and thus the patient was discharged home a few days later . on this admission , a large cardiac shadow was seen on the chest radiogram , and pericardial effusion confirmed on computed tomography ( ct ) of the thorax . the scan also demonstrated diffuse lymphadenopathy as well as extensive and multifocal thrombosis of the internal jugular veins bilaterally , the brachiocephalic vein and of the svc , managed with therapeutic dose of subcutaneous tinzaparin . further diagnostic screening for rheumatological , auto - immune and infectious causes was unremarkable , whilst lymph node biopsies were negative for malignancy . aspiration of the pericardial collection was suggestive of the presence of chyle , a suspicion that was confirmed on biochemical analysis of the aspirate . cytology and cultures of the aspirate were negative for malignant and infectious causes , respectively ( fig . figure 1:pre - operative chest radiograph and axial view of a ct thorax , demonstrating a large pericardial collection . pre - operative chest radiograph and axial view of a ct thorax , demonstrating a large pericardial collection . after pericardiocentesis , the patient had recurrence and was thus taken to theatre , underwent an anterior left mini - thoracotomy , through which a pericardial window was fashioned , 600 ml of chyle were collected and an 18 fr drain was placed in the pleural cavity . her postoperative course was uneventful , drain removed on day 3 , and she was discharged home as the collection and her symptoms had resolved . she remains symptom and collection free at 1 year postoperatively , with no evidence of recurrence on follow - up chest radiographs . the association of chylopericardium with trauma , previous thoracic or cardiac surgery , congenital lymphangiomas , radiation and malignancy is well recognized [ 25 ] . however , primary chylopericardium is a clinical entity that is more rarely encountered and only diagnosed if all known precipitants have been excluded [ 68 ] . its pathophysiology remains controversial , and is thought to be related to either elevated pressure in the thoracic duct , or to abnormal communications between the thoracic duct and the lymphatics of the pericardium [ 3 , 6 ] . clinical manifestations are varied as it is the age spectrum of patients affected , with reports of chylopericardium in neonates through to older adult . the imaging modalities that can be used to ascertain the underlying cause , with varying specificity and sensitivity , include lymphangioscintigraphy , lymphangiography , monitoring of chest radioactivity after oral intake of i - triolein and observation of the distribution of sudan iii dye in the pericardial cavity after ingestion [ 2 , 3 ] . however , the diagnosis still relies on the cytology , chemistry and microbiology of pericardial aspirate , obtained via pericardiocentesis . the management of this condition though controversial has two main therapeutic aims . this can be achieved via pericardiocentesis or surgically with the formation of a pericardial window / partial pericardiectomy , which can be combined with ligation of the thoracic duct and by conventional open methods or via video - assisted thoracoscopic surgery ( vats ) . the second aim is the avoidance of metabolic , nutritional and immunological compromise , resulting from the loss of chyle , via a diet rich in medium chain triglycerides or , if necessary total parenteral nutrition [ 2 , 9 , 10 ] . in this instance as pericardiocentesis is associated with a high incidence of recurrence , we opted for the pericardial window , combined with dietetic input to address the patient 's nutritional requirements . the patient having been informed of her options , opted for the option of conventional surgery in preference to vats , a method that can also be safely used for the same purpose [ 24 ] . the patient remains symptom - free a year postoperatively , and has been put on a surveillance programme with frequent follow - up . in conclusion , chylopericardium is a clinical entity that is not frequently encountered in the daily clinical practice and requires a high index of suspicion . its management needs to address both the prevention of cardiac tamponade and the correction of nutritional and metabolic compromise that can ensue .