Cytological diagnosis of a rare synchronous non-small cell lung cancer metastatic to the thyroid gland.

Abstract

Secondary neoplasms of the thyroid gland are quite uncommon with an estimated incidence rate of 0.1-3% 1,3 , representing either distant metastases or direct extension of tumors from adjacent anatomic structures. Metastases of primary lung cancers to the thyroid are even more unusual but the aggressive nature of lung malignancies often induces to palliative treatment, reasonably underestimating its incidence. In absence of a clinical history of primary tumor, specific symptoms and/or imaging data, the cytological differential diagnosis between primary thyroid cancer and metastatic lung carcinoma could be extremely challenging, especially in light of the overlapping morphological and architectural features.