Going into detail on what this term means and how it relates to health guidelines. This article may be incomplete.
Doctor speak for finding something unexpected and completely unrelated when searching for something else. Typically in reference to radiologic studies, for example, a CT scan of the abdomen following a mountain bike accident and finding an adrenal tumor. Usually implying something benign but requiring a work up, but not always. Occasionally the unexpected finding may lead to life saving treatment opportunities.