Respiratory Medicine CME
Volume 2, Issue 2 , Pages 68-69, 2009

Bilateral idiopathic chylothorax associated with light physical exercise

Service of Internal Medicine, University Hospital of Salamanca (Hospital ‘Los Montalvos’), Los Montalvos s/n, 37192 Salamanca, Spain

Received 16 September 2008; accepted 16 October 2008.

Article Outline

Summary 

Chylothoraces are associated with multiple etiologies including non-Hodgkin lymphoma and intrathoracic surgical trauma. In about 15% of cases no reason can be found for the chylous pleural effusion: most of these idiopathic chylothoraces are thought to be related to minor trauma. We present a case of bilateral idiopathic chylothorax temporally associated with light physical exercise.

A 74-year-old woman was brought to the hospital for evaluation of dyspnea and right-sided pleuritic chest pain. A chest roentgenogram demonstrated bilateral pleural effusion. The patient reported that the pain at the right side of her chest started abruptly 48h prior to admission, when she twisted right and hyperextended her spine to take up an object from the floor. Routine laboratory studies were within normal limits. Thoracentesis yielded a creamy–milky appearing fluid, with elevated tryglicerides levels (>575mg/dL). A computed tomography scan of the chest and abdomen was normal, except for the bilateral pleural effusion. After 72h of rest and low-fat diet the effusion completely resolved.

Idiopathic chylothorax in adults is an uncommon type of pleural effusion. Its diagnosis requires to rule out other etiologies. The treatment of choice is conservative.

Keywords: Idiopathic chylothorax, Chylothorax, Pleural effusion, Spontaneous chylothorax, Thoracic duct

 

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Case report 

Chylothorax is characterized by the presence of chyle, which is rich in triglycerides and chylomicrons, in the pleural space, and results from rupture, laceration or obstruction of the thoracic duct. It is the most frequent cause of pleural effusion in neonates, however, in adults it accounts for only 3% of cases.1

Chylothoraces are associated with multiple etiologies including non-Hodgkin lymphoma and intrathoracic surgical trauma, representing 50% and 25% of all causes, respectively. In about 15% of cases no reason can be found for the chylous pleural effusion: most of these idiopathic chylothoraces are thought to be related to minor trauma.1, 2, 3, 4

We present a case of bilateral idiopathic chylothorax temporally associated with light physical exercise (lateral hyperextension and rotation of the spine).

A 74-year-old woman with history of hyperlipidaemia for ten years was brought to the hospital for evaluation of dyspnea and right-sided pleuritic chest pain. She was first evaluated at the emergency room where a chest roentgenogram demonstrated a bilateral pleural effusion. There was no history of trauma, recent infection, fever or weight loss. The patient reported that the pain at the right side of her chest started abruptly 48h prior to admission, when she twisted right and hyperextended her spine to take up a knife from the floor, while cooking. Physical examination was unremarkable except for dullness to percussion and decreased breath sound over both lung bases. Routine laboratory studies (including complete blood count, erythrocyte sedimentation rate, coagulation, basic thyroid, liver and renal function tests, and lipid profile) were within normal limits. Thoracentesis yielded a creamy–milky appearing fluid, with protein levels of 4.2g/dL, glucose of 92mg/dL, LDH of 270IU/L (serum LDH: 321IU/L), cholesterol of 77mg/dL; triglycerides>575mg/dL, pH of 7.52, and a white blood cell count of 272/μL (25% polymorphonuclear leukocytes and 75% lymphocytes). Pleural fluid cytology, flow cytometry, acid fast bacillus smears, and microbiological cultures were negative. A computed tomography scan of the chest and abdomen was normal, except for the bilateral pleural effusion. Treatment consisted of relative rest and a medium-chain triglyceride diet. At 72h the effusion had completely resolved, and at twelve months, the patient remained asymptomatic.

Diagnosis of chylothorax is made when thoracentesis allows to obtain a creamy fluid with levels of triglycerides over 110mg/dL. In absence of previous surgical intervention, a computed tomography scan of the chest is useful to rule out the presence of malignancy or other conditions as the cause for the chyle leakage.5 Occasionally, a routine etiological evaluation of a chylothorax is negative. In these cases, further investigation can identify preceding nonpenetrating trauma to the chest related, for example, with a bout of cough, stretching, hiccupping, vomiting, jawing or seat belt harm. The temporal relationship between the injury and the appearance of the lymphatic effusion, together with the absence of a specific cause, leads to the diagnosis of ‘spontaneous’, idiopathic chylothorax.6

The course of the thoracic duct explains the different locations (left or right sided) of the pleural effusions according to the level of the injury. The thoracic duct crosses the mediastinum at the fifth thoracic vertebral body. Then, injury below T5 level results in a right-sided chylothorax (50% of the chylothorax), while injury to the thoracic duct above the T5 level leads to left-sided chylous effusions (35%). Since the thoracic duct usually crosses from the right to the left side of the thorax at the T4–T6 level, injury at this point might be expected to result in bilateral effusion,7 as in the case of our patient.

Chylothorax is usually initially treated conservatively (near 50% of the lacerations of the thoracic duct resolve spontaneously). Closed drainage is the initial step in large chylothoraces that cause respiratory distress, and etiologic treatment (radiotherapy, chemotherapy, corticosteroids…) has to be tried when indicated. Patients may require nutritional support to reverse hypovolaemia, immunosuppression and/or protein and electrolyte deficiencies. For this purpose a low-fat diet supplemented with medium-chain triglycerides, which are absorbed directly into the portal circulation, is employed. Somatostatin or octreotide infusions have been successfully used to reduce intestinal chyle production, decreasing the chyle leak.8 In chronic chylothoraces and in patients with rapid loss of nutrients into the pleural space, total parenteral nutrition is needed. Thoracoscopic or open surgical ligation of the thoracic duct is recommended for post-traumatic or post-surgical chylothoraces with high chyle drainage flows.9 Finally, pleuroperitoneal shunts, pleurodesis and percutaneous thoracic duct embolization or disruption, following lymphangio-graphy, are also employed in selected clinical settings.10

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References 

  1. Bernier C, Haouzi S, Bouvard E, Massiani MA, Meyniel D. Chylothorax spontané idiopathique. Revue de la littérature à propos d'un cas. Rev Pneumol Clin. 2000;56:369–373
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  7. Tankanow LB, Petrozzi C, Ward JC, Bower GC. Idiopathic bilateral chylothorax presenting as left-sided neck swelling. Henry Ford Hosp Med J. 1986;34:130–131
  8. Nair SK, Petko M, Hayward MP. Aetiology and management of chylothorax in adults. Eur J Cardiothorac Surg. 2007;32:362–369
  9. Fahimi H, Casselman FP, Mariani MA, Van Boven WJ, Knaepen PJ, Van Swieten HA. Current management of postoperative chylothorax. Ann Thorac Surg. 2001;71:448–451
  10. Boffa DJ, Sands MJ, Rice TW, Murthy SC, Mason DP, Geisinger MA, et al. A critical evaluation of a percutaneous diagnostic and treatment strategy for chylothorax after thoracic surgery. Eur J Cardiothorac Surg. 2008;33:435–439

PII: S1755-0017(08)00102-4

doi:10.1016/j.rmedc.2008.10.017

Respiratory Medicine CME
Volume 2, Issue 2 , Pages 68-69, 2009

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