The term pathognomonic in radiology, as well as clinical medicine in general, refers to a finding or a sign that is only found in a single specific condition or specific group of conditions, i.e. the finding has 100% specificity. Thus, by implication, a pathognomonic finding cannot and does not have a differential diagnosis.
A finding that is pathognomonic today may not be tomorrow. As new conditions are discovered, old conditions are re-classified, and case reports are published, pathognomicity can change. For example, for many decades, inferior rib notching was thought to be a pathognomonic appearance for coarctation of the aorta 1,2.
It does not imply anything about the sensitivity of the finding; indeed, the finding may be rare, and therefore, its absence cannot be taken as a comment on the likelihood of that condition occurring.
The term "Aunt Minnie" is sometimes also used for imaging signs/findings that are pathognomonic for a specific condition 3. However, while many Aunt Minnies are truly pathognomonic, some are merely classical for a particular condition but could be rarely found in other disease entities.
History and etymology
Pathognomonic derives from two Ancient Greek roots, παθος (pathos), meaning disease and γνωμων (gnomon), meaning indicator.
Unable to process the form. Check for errors and try again.