leonine facies leonine facies leonine facies is a facies that resembles that of a lion. it is seen in multiple conditions and has been classically described for lepromatous leprosy as well as paget's disease of bone. it is a dermatological symptom, with characteristic facial features that are visible on presentation, and is useful for focusing on differential diagnosis. leonine faciesugandan woman with leprosy exhibiting leonine facies.causesleprosy, paget's disease of bone associated conditions differential diagnoses include the following: lepromatous leprosy paget's disease of bone mycosis fungoides polyostotic fibrous dysplasia amyloidosis actinic reticuloid cutaneous t cell lymphoma leishmaniasis lipoid proteinosis progressive nodular histiocytosis mastocytosis hyperimmunoglobulin e syndrome, also known as job's syndrome