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Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
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Struma ovarii is composed entirely of -
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The correct answer is  Struma ovarii is a specialized teratoma which is always unilateral and is composed of mature thyroid tissue. It may manifest itself with the features of hyperthyroidism.