Intimal pulmonary sarcoma: A case report of a rare differential diagnosis of chronic thromboembolic pulmonary hypertension

Pulmonary angiosarcoma is a rare and malignant disease of the blood vessels. Initially, it can be misdiagnosed as chronic thromboembolic hypertension (CTEPH). In CTEPH, there is increased pressure and resistance of the pulmonary arteries following persistent obstruction of pulmonary circulation from (recurrent) thromboembolism despite adequate anticoagulative treatment. A 76-year-old patient was referred to our centre for pulmonary hypertension after a central, left-sided, subacute pulmonary thromboembolism had been observed 7 months earlier. It was treated with apixaban, but the patient described persistent dyspnoea and cough. We observed severely reduced diffusion capacity, ineffective ventilation during cardiopulmonary exercise testing and right heart strain on echocardiograph, signs that are in agreement with suspected CTEPH. Computer tomography of the chest showed a persistent, size-constant obliteration of the left main pulmonary artery, and ventilation perfusion scan confirmed complete interruption of perfusion. We suspected malignancy; PET-CT scan confirmed metabolically active lesions. Histopathological examination of a sample obtained from the lesion by endobronchial ultrasound-guided needle aspiration showed a sarcomatous tumour with amplification of the MDM2-gene. We diagnosed an intimal angiosarcoma of the left pulmonary artery and referred the patient to pneumectomy. Angiosarcoma of the pulmonary arteries is a rare differential diagnosis of persistent thrombotic lesion and suspected CTEPH. In 2015 there were less than 300 cases described. Pulmonary angiosarcoma should be considered if: lesion occupies the entire lumen of pulmonary arteries with dilatation, contrast enhancement and infiltration of the wall in radiological examination, FDG-PET CT reveals metabolically active lesions, no pulmonary thromboembolism was documented in the anamnesis, increase in size is seen despite anticoagulation, patient presents with B symptoms. Diagnosis confirmed by biopsy, resection of tumour and removal of metastases is the therapeutic standard. Median survival remains poor. Further research is needed for improved diagnosis and treatment.