A 49-year-old man with metastatic renal cell carcinoma (case 4).
A, B. Initial ultrasonography (A, longitudinal; B, color Doppler) shows a 1.0×0.8×1.2-cm hypoechoic solid nodule with a well-defined smooth margin and increased vascularity. The initial fine-needle aspiration (FNA) had a result of benign (Bethesda category 2). After 34 months, the patient presented with a palpable neck mass. C, D. Follow-up ultrasonography (C, longitudinal; D, color Doppler) reveals an increased nodule size (1.7×1.4×4.1 cm) with similar ultrasonographic features. The second FNA had a nondiagnostic result due to the paucity of retrieved cells. A subsequent core needle biopsy revealed metastatic renal cell carcinoma.