Popliteal Sarcomas Masquerading as Popliteal Aneurysms: Case Reports

Popliteal masses are frequently referred to vascular surgeons with a presumptive diagnosis of popliteal aneurysm. Evaluation by the vascular surgeon must exclude other diagnoses such as Baker's cyst or neoplasm. This case report focuses on two patients referred to the vascular surgery service with popliteal masses. The first patient had a prior popliteal aneurysm repair and the second patient was thought to have a popliteal aneurysm without palpable pedal pulses. Evaluation included duplex ultrasound scanning and imaging with either computed tomography or magnetic resonance. After these studies were performed, both patients underwent fine needle aspiration (FNA) to determine the cytologic features of the masses. Final diagnosis for each patient was a soft tissue sarcoma. The differential diagnosis of a popliteal mass should include both nonneoplastic and neoplastic etiologies. If a neoplasm is suggested, FNA can help differentiate between benign versus malignant and primary versus metastatic disease. Many soft tissue lesions can then be treated based on clinical, radiologic, and cytologic data without the need for open biopsy. Since FNA has a low morbidity rate, the authors recommend early FNA in the evaluation of soft tissue popliteal masses. These cases are reported so that vascular surgeons will be prepared to evaluate patients with popliteal masses for diagnoses other than popliteal aneurysms.