Acute Pulmonary Artery Obstruction as the Primary Manifestation of a Rapidly Growing Intimal Sarcoma in a 54-Year Old Patient

Introduction: We report on a 54-year old male patient without a prior medical history, who presented with acute onset of non-exercise related chest pain, suspicious of a pulmonary artery embolism (PE).

Background: A chest X-ray revealed suspicious solitary pulmonary nodules in a racemose cluster in the left upper pulmonary lobe. The following CT scan verified solitary soft tissue lesions extending from the left hilum to the lateral left upper lobe pleura with in-growth into adjacent blood vessels. In addition, an abdominal scan showed hepatic lesions consistent with cysts or cystic metastases. In a transbronchial biopsy no malignant cells were detected. The patient was then discharged and developed recurrent episodes of fever with a beginning systemic septic reaction. Systemic antibiotic therapy did not show an improvement of the clinical situation. Blood test results showed a procalcitonine level of over 20 µg/l. CT scans were then repeatedly performed and revealed a rapid progress of the tumor mass. A complete occlusion of the left main pulmonary artery with tumor protruding into the pulmonary trunk became apparent. Based on the progressive character of the disease, the decision for a left-sided pneumonectomy with extracorporal circulatory support for pulmonary trunk repair was made.

The procedure was performed via a left antero-axillary thoracotomy. Intraoperatively, the lung was found strongly attached to the chest wall. An extended pneumonectomy with partial pleurectomy and pericardiectomy due to tumor infiltration and lymph node dissection was performed. Palpable tumor nodes were soft, the pulmonary artery was filled with a mucinous, amber-colored mass. In an intraoperatively performed frozen-section, the dignity of the explanted tumor could not be specified. Histological analysis and tumor typing later revealed the diagnosis of an intimal sarcoma. The patient recovered quickly and adjuvant chemotherapy was initiated.

Discussion: The pulmonary intimal sarcoma is a rare malignant neoplasm with an incidence of ∼0.001% and has only been reported in a few hundred cases. Median survival time without therapy ranges at ∼1.5 months and surgical resection is the treatment of choice. PE and alveolar echinococcosis are important differential diagnoses. Diagnostic workup however, should not postpone surgery.