About papillary carcinoma thyroid true statements is/are: 1. Radiation is a risk factor 2. Multifocal 3. Hematogenous spread is common 4. Distant metastasis is seen 5. Most common in iodine deficient areas

Thyroid cancer cases occur primarily in iodine deficient area. The use of external beam irradiation has been shown to result in an increase incidence of well- differentiated carcinoma ( usually papillary ) at any time, generally 5 years after exposure" "Spread to lymph node is common but blood borne metastasis are unusual unless the tumor is extrathyroid" Major difference between papillary and follicular carcinoma Papillary (%) Follicular (%) Male incidence 22 35 Lymph node metastasis 35 13 Blood vessel invasion 40 60 Recurrence rate 19 29 Overall moality rate 11 24 Location of recurrent carcinoma Papillary (%) Follicular (%) Distant metastasis 45 75 Nodal metastasis 34 12 Local recurrences 20 12 Ref: Sabiston 18/e, page 938; bailey & love 25/e, page 793-94; harrison 17/e, page 2245.