M61: Calcification and ossification of muscle

Calcification and ossification of muscle refer to a group of conditions marked by abnormal deposits of calcium or bone tissue in muscle structures. These anomalies might emerge due to numerous factors including aging, injury, genetic tendencies, or as a complication of another disease. On the onset, these conditions may often present as hard, painful lumps beneath the skin, muscle stiffness, or a limitation in the range of motion. With time, these deposits may enlarge and further impede movement, leading to discomfort and potential functional impairment. They primarily affect the muscular system, but can also involve connective tissues and skin. It is essential to understand that these conditions are typically progressive, implying they might worsen over time if left untreated. Additionally, the calcification or ossification may occur in any muscle in the body, yet commonly involves the larger muscle groups such as those in the thighs, arms, or back.