Teaching Case

Acute dyspnea and rapid occurrence of anaemia

The patient, affected by the Rendu-Osler-Weber disease, complained of dyspnea. Laboratory findings: rapid occurence of anaemia (Hb:9,4mg/dl). A standard chest radiography revealed pleural effusion at the left hemithorax ; a polylobate nodule (3 cm in diameter) was also detected at the left lung base (see images 1a and 1b). After 2 days the symptoms worsened (increase in dyspnea, Hb: 7,9mg/dl, pO2: 49mmHg, pCO2: 32,3mmHg); for this reason a further standard chest radiography was performed: it revealed complete opacity of the left lung associated to right dislocation of the mediastinum (see image 1c). In addition a contrast enhanced CT of the thorax was performed (see image 2). Few hours later the patient died.

The Rendu-Osler-Weber (RWO) disease or hereditary hemorrhagic telangiectasia is a rare (about 1-2/100000 in European population) autosomal dominant inherited disorder which may give rise to arteriovenous malformations localized in the microcircle of the derm, in telangiectasic shape. Frequently they involve the nose, lips, conjunctivae, mucosal surface, nailbed and the distal portion of the limbs. Sometimes the RWO disease is associated with vascular anomalies in other organs, particularly in the pulmonary, hepatic and cerebral circulations. Gastrointestinal bleeding and epistaxis represent the most common clinical features. Dyspnea, cyanosis, digital clubbing and rarely cardiac failure may occur particularly in case of pulmonary arteriovenous fistula with high flow or right to left shunt. Because of paradoxical emboli, various central nervous system complications have been described, including stroke and brain abscess. A pulmonary arteriovenous malformation can also bleed and results in hemoptysis and hemothorax. At standard chest radiography arteriovenous malformations appear as lobulated nodular lesions, located at central or peripherical lung area with linear stria connecting to homolateral pulmonary hilum. This linear stria represents the tortuous feeding arteries and draining veins. On CT scan it is possible to reveal a nodular lesion with sharp edges, parenchymatous density and homogeneous enhancement. Afferent vessels originating from bronchial artery can be found, as well as ectasic efferent vessels coming from arteriovenous malformations and flowing into a pulmonary vein.