Clinical signs are highly variable, and are not sufficient in themselves to make a diagnosis: the wrist or lower limbs may show a noticeable “arched tibia”-type deformity, or lumps may appear on the phalanges.
Diagnosis can only be confirmed by radiological examination, which is reliable and unequivocal. Referral to an orthopedic surgery consultation is recommended.
Other complementary examinations (scintigraphy, MRI, ultrasound) are not useful for diagnosis.
Clinical palpation can help locate certain chondromas, particularly on the ribs.
When the diagnosis has been made before the age of 2, it is advisable to carry out a new radiographic assessment before the age of 6-7, in order to locate the damage more precisely. In fact, chondromas probably exist from birth, but they are not or hardly visible at this stage.
The main differential diagnosis is exostosing disease. Radiological examination can easily distinguish these two entities, which are histologically and radiologically distinct. Unlike Ollier-Maffucci disease, which is non-transmissible, exostosing disease is an autosomal dominant genetic disorder (hereditary disease with a 50% risk of transmission).