Papillary thyroid carcinoma with nodular fasciitis-like stroma: a case report.

Papillary thyroid carcinoma (PTC) is the most frequently occurring malignant neoplasm of the thyroid gland and is known to have several morphologic variants. PTC with nodular fasciitis-like stroma (PTC-NFS) is one of the unusual variants of PTC, with only a few cases being reported in the literature. This neoplasm is characterized by extensive reactive stromal proliferation, which may occupy 60 to 80% of the tumor along with areas of a typical papillary carcinoma. We report a case of PTC-NFS and address the diagnostic difficulties posed by the condition's extensive reactive stromal proliferation. We also emphasize that when one encounters a fibroproliferative lesion of the thyroid, a diligent search should also be made for PTC to avoid diagnostic errors.