Alterations in the symptoms or appearance of other symptoms is suggestive of a complication or change in the nature of original disease ie malignant process especially if there are constitutional symptoms such as loss of appetite or weight loss. I think history be combined with physical signs to arrive at the DD. I am afraid our respected teachers of the past like myself placed too much importance to the history in an era of minimal investigations like US, CT, endoscopy etc. with due respect to the worthy examiners post graduate studies are about management options, sequels of treatment and prognosis.