When palpating the abdomen and feeling a small mass, what is the recommended next step?

When palpating the abdomen and encountering a small mass, examining with abdominal muscles tensed is the recommended next step for several reasons. Tensing the abdominal muscles can help provide additional information about the mass, such as whether it is a solid or cystic structure, its mobility, and its relationship to surrounding tissues. This manipulation may also reveal clues about the mass's characteristics and whether it is fixed or freely movable, which can significantly affect the clinical assessment.

Examining the mass while the abdominal muscles are relaxed can sometimes provide a clearer evaluation since tight muscles may mask certain features of the mass. Therefore, testing the mass's characteristics under different conditions can enhance the examiner’s understanding of the likely pathology involved.

The other options—ultrasound, surgery referral, and measuring size by percussion—are additional steps that might be taken after an initial assessment, but first evaluating the mass through palpation techniques while assessing muscle tension is key in forming a preliminary impression. This foundational information can guide further diagnostic or therapeutic actions appropriately.