A patient with long standing multinodular goitre develops hoarseness of voice ; also, the swelling undergoes sudden increase in size. Likely diagnosis is:

Hoarseness of the voice and sudden increase in size of swelling in a patient with multinodular goitre indicate malignant changes. Hoarseness of the voice indicates recurrent laryngeal involvement or vocal cord paralysis. Incidence of Follicular carcinoma is high in endemic goitrous areas, with long standing multinodular goitre, possibly owing to persistent TSH stimulation. Ref: Primary Care Medicine: Office Evaluation and Management of the Adult Patient By Allan H. Goroll, Albe G. Mulley, 2009, Page 736.