An Uncommon Presentation of Pulmonary Cannonball Metastasis

SESSION TITLE: Pulmonary Manifestations of Systemic Disease 1 SESSION TYPE: Affiliate Case Report Poster PRESENTED ON: Tuesday, October 31, 2017 at 01:30 PM - 02:30 PM INTRODUCTION: Pulmonary cannonball metastases are large, well-circumscribed lung lesions that resemble cannonballs. This pattern of metastasis most commonly occurs in patients with renal cell carcinoma or choriocarcinoma and less commonly in patients with synovial sarcoma. We present a case of pulmonary cannonball metastasis diagnosed at the same time as the primary synovial sarcoma. CASE PRESENTATION: A 61-year-old male smoker presented with right leg pain after suffering a mechanical fall. Examination showed right lower leg swelling and tenderness prompting a venous doppler ultrasound. Right popliteal and tibial trunk veins were non-compressible and calf veins were not visualized due to significant edema. Anticoagulation was initiated with rivaroxaban. One month later, the right leg is persistently edematous and firm, and the patient now reported fatigue and weight loss. Chest radiography showed several large nodular densities measuring up to 6.7 cm and a large right-sided pleural effusion were seen (Figure 1). Computed tomographic (CT)-angiography of the right lower extremity revealed a large 11.6 cm soft tissue mass within the posterior compartment muscles of the calf encasing the distal popliteal and posterior leg compartment vessels. Right inguinal lymphadenopathy was also present. The patient was directly admitted to the hospital for work-up and treatment. Tissue biopsy of the calf mass diagnosed monophasic synovial sarcoma. Pleural fluid was exudative but negative for malignancy. Hypoxia and dyspnea worsened despite therapeutic thoracentesis and absence of pneumothorax on chest X-ray. CT of the chest showed multiple filling defects consistent with pulmonary emboli and demonstrated cannonball pleuro-pulmonary metastasis (Figure 2). CT-guided lung biopsy was positive for monophasic synovial sarcoma. Considering the size of the mass and extent of the metastasis only palliative measures were available. Above the knee amputation was done for local symptom control (pain, paresthesias, compartment syndrome). Treatment with doxorubicin was initiated to decrease tumor burden and improve functional status, however the disease progressed and the patient passed away. DISCUSSION: Cannonball metastases are not commonly present at the time of diagnosis of synovial sarcoma. Poor prognosis is associated with monophasic subtype, primary tumor size greater than 4 cm, proximal location, and age over 50, all of which characterizes our patient’s case. Interestingly, despite impressive tumor burden, our patient initially presented with a deep venous thrombosis, without initial complaints of shortness of breath. CONCLUSIONS: This case highlights the importance of obtaining chest imaging in patients with soft tissue sarcoma to evaluate for pulmonary disease albeit lack of respiratory symptoms. Reference #1: Baheti, A.D. et al. Br J Radiol. February 2015; 88(1046): 20140608. Reference #2: Ferguson, P.C. et al. Cancer. 2011 Jan 15;117(2):372-9. Reference #3: Navarria, P. et al. Eur J Cancer. 2015 Mar;51(5):668-74. DISCLOSURE: The following authors have nothing to disclose: Stephanie Cull, Rania Farhat, Abhishek Krishna, Soophia Naydenov No Product/Research Disclosure Information