<prompt> Most common malignancy arising in the thyroglossal cyst isFollicularPapillaryMedullaryAnaplastic  <response>: Thyroglossal CystContains clear to a cloudy fluid with sparse cellularityThe cystic background contains few if any epithelial cellsSome inflammatory cells and crystals might be presentRarely malignant transformation occurs in about 1 of the casesMost common malignancy arising is papillary carcinoma followed by squamous cell carcinomaRef: PL Dhingra, Diseases of Ear, Nose Throat, 7th edition, pg no. 378 - 379 