<prompt>  A 30 year old female patient complains of painless hard anterior neck mass. FNAC was inconclusive. Open thyroid biopsy was performed which revealed the fibrous nature of the mass, woody, non tender thyroid, mimicking carcinoma is observed. The diagnosis points towardsDe Quervains thyroiditisRiedels thyroiditisHashimotos thyroiditisNone of the above 