To date, it is not clear whether TSH is involved in
the development or progression of this disease, or possibly
both. Experimental data suggest that the TSH signaling
pathway may predispose thyroid cells to BRAF-induced
transformation.Alternatively, some studies have suggested
that TSH is not likely to be involved in the de novo oncogenesis
of papillary thyroid carcinoma (PTC) and that this
hormone might play a role in the progression and growth
of preexisting tumors.However, the existence of a possible
relationship between tumor size and TSH level has
not yet been determined. The few studies that have analyzed
the association of TSH levels with papillary thyroid
microcarcinomas (PTC with a diameter equal to or smaller
than 10 mm) have arrived to conflicting conclusions.