This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
[{'content': 'Pathologic calcification is seen in \nSelect and explain. \nA. Scleroderma, B. Lichen planus, C. Dystrophic epidermolysis bullosa, D. Lupus erythematosus', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Systemic sclerosis:\n\nCharacterized by ultimate induration and atrophy of skin and fixation of epidermis to deeper subcutaneous tissues. The skin becomes hardened and atrophic and cannot be wrinkled or picked up because of its firm fixation to the deep connective tissue. This contracture of skin gives a mask-like appearance to the face of claw-like appearance to hands.\nScleroderma can be circumscribed (morphea) or linear (Coup de sabre).\nThe tongue becomes stiff and board like, causing the patient difficulty in eating and speaking.\nReduced opening of mouth and fixation of jaw as a result of involvement of the peritemporo mandibular joint tissues making dental care very difficult.\nSome times deposition of calcium in affected areas is also found.\n\nRadiographic features:\n-\xa0\xa0\xa0\xa0 Extreme widening of PDL, two to four times normal thickness is diagnostic.\n-\xa0 \xa0 Bone resorption of angle of mandibular ramus and partial or complete resorption of condyles and/or coronoid processes of the mandible are also seen.\n\nOverall, increased collagen in tissues is characteristic feature of systemic sclerosis or scleroderma.', 'role': 'assistant'}]