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: Radiology
[{'content': 'The mother brings her 2 year old child  to OPD with gum swelling on lower back tooth region. On intraoral examination, smooth - surfaced bluish lesion associated with erupting 75. Radiographic examination reveals a soft tissue shadow \n and there is no bone involvement. What is the most probable diagnosis? \nSelect and explain. \nA. Eruption cyst, B. Dentigerous cyst, C. Nasolabial cyst, D. Any of the above', 'role': 'user'}, {'content': "Answer: A \nExplanation: Eruption\xa0cyst\xa0is\xa0defined\xa0as\xa0an\xa0odontogenic\xa0cyst\xa0with\xa0the histologic features of a dentigerous cyst that surrounds a tooth\xa0crown that has erupted through bone, but not soft tissue and is\xa0clinically\xa0visible\xa0as\xa0a\xa0soft\xa0fluctuant\xa0mass\xa0on\xa0the\xa0alveolar\xa0ridges. An\xa0eruption\xa0cyst\xa0or\xa0‘eruption\xa0hematoma’\xa0is\xa0in\xa0fact\xa0a dentigerous cyst occurring in the soft tissues (Shear, 1992).\xa0Whereas, the\xa0 dentigerous\xa0cyst\xa0develops\xa0around\xa0the\xa0crown of\xa0an\xa0unerupted\xa0tooth\xa0lying\xa0in\xa0the\xa0bone,\xa0the\xa0eruption\xa0cyst\xa0occurs when a tooth is impeded in its eruption within the soft tissue overlying the bone.\nShafer's Oral pathology Pg- 263, 264", 'role': 'assistant'}]