People often first notice metachondromatosis in childhood when small, painless bony bumps appear near the bases of the fingers or toes, sometimes curving the fingers inward. Doctors may spot the first signs of metachondromatosis on hand or foot X-rays after a parent observes new lumps or mild changes in finger alignment, while growth and overall health usually remain typical. Unlike other bone bump conditions, these lesions can shrink over time and mainly affect the hands and feet, which helps clinicians recognize how metachondromatosis is first noticed.