**Core Concept**
Pathologic calcification refers to the deposition of calcium salts in tissues, often resulting from injury, inflammation, or metabolic disorders. This process can lead to the formation of calcified nodules or plaques, which can cause tissue hardening and dysfunction.

**Why the Correct Answer is Right**
Scleroderma, also known as systemic sclerosis, is a chronic autoimmune disease characterized by excessive collagen deposition and fibrosis in the skin and internal organs. Pathologic calcification is a common feature of scleroderma, particularly in the skin, where it can lead to the formation of calcinosis cutis. This calcification is thought to result from the abnormal deposition of calcium salts in areas of tissue injury and inflammation.

**Why Each Wrong Option is Incorrect**
**Option A:** Lichen planus is an inflammatory disease that affects the skin and mucous membranes, characterized by a distinctive purplish rash and blistering. While lichen planus can cause scarring and tissue damage, pathologic calcification is not a typical feature of the disease.
**Option B:** Dystrophic epidermolysis bullosa is a genetic disorder that affects the skin and mucous membranes, causing blistering and scarring. While dystrophic epidermolysis bullosa can lead to tissue damage and fibrosis, pathologic calcification is not a characteristic feature of the disease.
**Option C:** Lupus erythematosus is a chronic autoimmune disease that can affect multiple organ systems, including the skin, joints, and kidneys. While lupus can cause inflammation and tissue damage, pathologic calcification is not a typical feature of the disease.

**Clinical Pearl / High-Yield Fact**
When considering the diagnosis of pathologic calcification, remember that it is often associated with conditions characterized by chronic inflammation, tissue injury, or metabolic disorders. Calcinosis cutis, a type of pathologic calcification seen in scleroderma, can be a diagnostic clue for this condition.

**✓ Correct Answer: A. Scleroderma**