Tumor

A tumor is an abnormal growth of tissue that forms when cells divide and multiply more than they should, or when cells that should die do not. Tumors can be benign (non-cancerous) or malignant (cancerous). Ultrasound is a primary tool for detecting and characterizing tumors throughout the body. Sonographic features that help distinguish benign from malignant tumors include margins (smooth and well-defined versus irregular and infiltrative), internal composition (homogeneous versus heterogeneous with necrosis), vascularity on Doppler (organized peripheral flow versus chaotic internal flow), posterior features, and growth pattern over time. While ultrasound can suggest whether a mass is likely benign or malignant, definitive diagnosis usually requires tissue sampling (biopsy) or other imaging for complete characterization.