Not Your Usual Pulmonary Embolism.

SESSION TITLE: Pulmonary Vascular Disease CasesSESSION TYPE: Affiliate Case Report SlidePRESENTED ON: Monday, October 27, 2014 at 03:15 PM - 04:15 PMINTRODUCTION: Leiomyosarcoma is a rare malignant tumor of the lung. It originates in the smooth muscle cells and 2% of leiomyosarcomas are vascular. Pulmonary artery (PA) leiomyosarcomas are highly malignant and locally invasive.CASE PRESENTATION: We describe a case of 47-year-old nonsmoker man who presented with a chronic dry cough. He denied any dyspnea and had a CT which showed a large filling defect in the left main PA. The patient was started on anticoagulation therapy with LMWH and then maintained on warfarin. He presented four months later with worsening dry cough and lightheadedness but was hemodynamically stable. Physical examination was significant for normal lung exam and an accentuated second heart sound. CT chest showed progression of the previous filling defect with a saddle embolus in the main PA (A). Patient underwent surgery for embolectomy and was found to have a large mass within the PA. On histopathology the cells were pleomorphic with mitosis (B) and positive for desmin and SMA on immune stains confirming the diagnosis of PA leiomyosarcomas.

DISCUSSION: Diagnosis of primary PA leiomyosacroma is challenging since the filling defect noted in the PA is often misinterpreted as an embolus and patients are started on anticoagulant therapy as in our case. A key clue can be the discrepancy between the size of the filling defect and the relative lack of symptoms one would expect from an embolus this size. CT findings of neoplasm include complete occlusion of the PA lumen, expansion of the artery or extraluminal extension and heterogeneous appearance. MRI reveals better characterization of the soft tissue mass. PET scan is the diagnosis of choice in differentiating PE from neoplasm by degree of metabolic activity. Early diagnosis can be achieved by endovascular aspiration of blood using catheter. Microscopically they are composed of pleomorphic spindle cells. The prognosis is extremely poor. Radical surgical resection is the mainstay of treatment. Most of the reported patients were operated on for presumed PE as in our patient.CONCLUSIONS: PA sarcoma should be in the differential diagnosis of patients with huge PE with atypical clinical presentation Reference #1: Jelacic S, et al. Near total occlusion of the main PA and destruction of PV by leiomyosarcoma. Anesth Analg. 2013 Jan;116(1):53-6.Reference #2: Yamasaki M, et al. PA Leiomyosarcoma Diagnosed without Delay. Case Rep Oncol. 2011 May;4(2):287-98.Reference #3: Adeli SH, et al. Pulmonary Hypertension due to a PA Leiomyosarcoma: A Case Report. Case Rep Pulmonol. 2013;2013:160619.DISCLOSURE: The following authors have nothing to disclose: Rania Abdallah, Sunita Kumar, Christina Kwong, Xiuzhen DuanNo Product/Research Disclosure Information.