Primary lung carcinoma spreading to pulmonary vessels and presenting as a thromboembolic disease is quite rare and only few individual cases have been reported in the English literature.1-3 The prognostic significance of pulmonary vessel invasion by lung carcinoma is unclear and the treatment is challenging. We aim to describe an unusual case of sarcomatoid carcinoma of the lung characterised by its hilar localization.1,2
A 68-year-old man, 80 pack-year smoker, consulted for a 4-month-lasting effort dyspnea of New York Heart Association (NYHA) functional class II and dry cough. Physical examination revealed a grade III/IV ejection systolic murmur in the aortic area. Chest X-ray showed a heterogeneous poorly defined opacity of the right hilius without cardiomegaly (Figure 1). Electrocardiogram showed a regular sinusoidal rhythm and a tachycardia at 100 beats/min without signs of left ventricular hypertrophy. A two-dimensional (2D) transthoracic echocardiography (TTE) showed a severe aortic stenosis. The left ventricular ejection fraction was estimated to 70%. There was no pulmonary arterial hypertension. The pulmonary artery systolic pressure was estimated to 30 mm Hg. A computed tomography (CT) scan revealed a thrombus in the lower branch of the right pulmonary artery of tumoural appearance extending to the right lower lobe artery (Figure 2). Bronchial fibroscopy was normal. No distant metastasis was revealed by the cerebral CT scan or the abdominal CT scan. The lung function was within normal values. Surgical resection of the arterial process and aortic replacement was decided.
Surgical resection was performed through a median vertical sternotomy. The procedure consisted of a right intra pericardial pneumonectomy with aortic valve replacement by a mechanical valve. A mediastinal lymph node dissection was also performed. Postoperative macroscopic examination of the resected specimen showed a 2 cm tumour encompassing the pulmonary artery and developing into the sub-intima without endoluminal component (Figure 3A). The extemporaneous exam concluded to a sarcomatous tumour. Definitive microscopic findings consisted in a malignant proliferation with wide necrosis composed of tumour cells of variable size with abundant eosinophilic cytoplasm and atypical nuclei. Some tumour cells were multinucleated (Figure 3B). Immunohistochemical study revealed the co-expression of cytokeratin and vimentin antibodies by the tumour cells (Figure 3C and D). Other antibodies including anti-smooth muscle actin and desmin weren’t expressed, ruling out the diagnosis of a muscle differentiated tumour. The mediastinal lymph nodes dissected were benign.
These morphological and immunohistochemical features were consistent with a primary sarcomatoid carcinoma of the lung invading the pulmonary artery classified as a pT1N0M0 tumour. Molecular studies highlighted no epidermal growth factor receptor (EGFR), Her mutations, anaplastic lymphoma kinase (ALK) translocation or c-met amplification.
There were no postoperative serious complications except for an atelectasis with oxygen dependency. This complication was managed by a non-invasive ventilation and chest physiotherapy with a good outcome. The patient was discharged 18 days after the surgical resection. He is still followed by the oncologist, and after 4 months of follow-up, presented no complications.