Would you evaluate for an ectopic source in a patient with persistently elevated IGF-1 level but no clinical features of acromegaly or evidence of pituitary abnormalities?   

Is this an IGF-1 drawn in the same lab? This may be falsely elevated. If so, I would repeat in a different lab or confirm/rule out acromegaly diagnosis by glucose suppression test. If the diagnosis is confirmed, measurement of GHRH to rule out a GHRH-secreting NET would be the next step.