The diagnostic value of silver stool (Thomas’ sign)
Authors: Tang TY, Walsh SR and Clarke JMF
Heneage Ogilvie first described Thomas’ sign in 1955 in the Medical Memoranda of the BMJ but unfortunately did not publish a picture. He selflessly admitted that his pathology colleague, Dr Thomas, whom this sign is named after, had pointed out earlier that patients with cancers involving the Ampulla of Vater sometimes pass ‘‘silver stools’’ i.e. motions having the colour of oxidized silver or aluminium paint. The silver stool is a combination of the white stool of obstructive jaundice and the black stool of melaena. He concluded that Thomas’ sign is diagnostic of cancer of the Ampulla of Vater, and would enable this eminently curable lesion to be recognized at an early and operable stage.