Stumbling on the diagnosis: a rare case of metastatic pulmonary artery intimal sarcoma

SESSION TITLE: Rare Presentations of Cancer SESSION TYPE: Rapid Fire Case Reports PRESENTED ON: 10/09/2023 09:40 am - 10:25 am INTRODUCTION: Sarcomas are uncommon, accounting for approximately 1% of all adult cancers (2). Pulmonary artery intimal sarcomas (PAS) are even rarer, with a prevalence of 0.001–0.003% (1-2). Early diagnosis and treatment of PAS are important due to their aggressive nature. However, diagnosis is often difficult due to radiological and clinical findings that mimic other pulmonary diseases, in particular pulmonary thromboembolism. Here we illustrate an incidental diagnosis of metastatic PAS. CASE PRESENTATION: A 57-year-old male presented to our clinic 5 months after falling in the shower. He did not seek medical attention. Two weeks later, he complained of a dry cough that persisted for 3 months. No associated shortness of breath. CXR ordered by his PCP revealed a moderate right pleural effusion. Further evaluation with contrast CT of his chest revealed an old right 12th rib fracture and a moderate right pleural effusion. Cardiothoracic surgery advised outpatient follow-up in one month with a repeat CT scan to evaluate for resolution of the pleural effusion. His insurance denied the study, prompting him to change providers and ultimately lose his PCP. This led him to us. Repeat CT imaging showed resolution of the pleural effusion, however, there were multiple right subpleural nodules, right hilar mass encasing the bronchus, and right pulmonary artery obstruction. CT angiogram of the chest was negative for pulmonary embolism but did reveal occlusion of the right middle and lower lobes of the pulmonary artery by a 3.3cm right lower lobe mass. Biopsy via bronchoscopy was positive for intimal sarcoma. PET CT revealed a 4cm primary intimal malignant neoplasm obstructing the lobar and segmental branches of the right lower and middle lobe pulmonary artery. There were also multiple nodular metastases in the right lower lobe of the lung. No extra-thoracic disease. He struggled to find a provider willing to take his case, leading to a 3-month delay from diagnosis to treatment initiation. He eventually completed 7 rounds of neoadjuvant chemotherapy with doxorubicin and ifosfamide, followed by bilobectomy of the right middle and lower lobes. DISCUSSION: PAS can manifest with protean respiratory symptoms, mimicking a variety of pulmonary diseases, in particular pulmonary thromboembolism. As such, one should maintain a high level of suspicion for PAS in patients diagnosed with pulmonary thromboembolic disease with persistent respiratory complaints despite optimal treatment. Currently, the mainstay of therapy is surgical, with the goal of complete resection with clear margins. Studies show that patients who receive complete resections have longer overall survival rates compared to those with incomplete resections (median overall survival 36.5 vs 11 months) (3). There are currently no clear recommendations regarding the utility and choice of additional medical or radiotherapy. CONCLUSIONS: Our case adds to the limited literature on PAS. It also highlights the challenges that patients with rare diseases face while navigating the healthcare system. There were several delays in his care due to mishaps with insurance and difficulty finding providers willing to take on his case. The establishment of a national network of providers specializing in PAS management may help mitigate this issue moving forward. REFERENCE #1: A.P. Burke, R. Virmani. Sarcomas of the great vessels. A clinicopathologic study. Cancer, 71 (5) (1993), pp. 1761-1773 REFERENCE #2: Jemal A, Siegel R, Ward E, Murray T, Xu J, Thun MJ. Cancer statistics, 2007. CA Cancer J Clin. 2007 Jan-Feb;57(1):43-66. doi: 10.3322/canjclin.57.1.43. PMID: 17237035. REFERENCE #3: S.H. Blackmon, D.C. Rice, A.M. Correa, R. Mehran, J.B. Putnam, W.R. Smythe, et al. Management of primary pulmonary artery sarcomas. Ann. Thorac. Surg., 87 (3) (2009), pp. 977-984 DISCLOSURES: No relevant relationships by Patton Adderley No relevant relationships by Stuart Bagatell No relevant relationships by Claudia Tejera Quesada