Because there is often a large, hard mass of stool that has «backed up» in your child's rectum, your child may need a «clean out» or disimpaction before dietary and maintenance therapy will work. (verywellfamily.com)
Went to open the first foil pack and noticed it wasn't sealed completely and the powder was caked into hard masses. (amazon.com)
Some animals develop hard masses in the skin on the neck and back (from calcium deposits, a symptom called calcinosis cutis), which may ulcerate or become infected. (brittonroadveterinaryclinic.com)