Table 1.

Histological thyroid cancer subtypes

Histological thyroid cancer subtypes	Description
DTC [PTC (80% cases); FTC (11% cases); Hürthle cells TC]	Tumor dedifferentiation in DTC occurs in up to 5% of tumors and it is associated with a more aggressive behavior and loss of iodide uptake
PDTC	It is a subset of thyroid tumors more aggressive than DTC
ATC	Highly aggressive, undifferentiated thyroid cancer (2% of all TCs)
MTC [Sporadic (75%) or hereditary (25%); hereditary MTC might be (a) FMTC, defined by the presence of MTC alone; (b) involved in MEN2 syndrome]	It is derived from C cells (2%–5% of all TCs)
Lymphomas and sarcomas	Rare TCs

Abbreviations: DTC, differentiated thyroid cancer from follicular cells; PTC, papillary thyroid cancer; FTC, follicular thyroid cancer; TC, thyroid cancer; PDTC, poorly differentiated thyroid cancer; ATC, anaplastic thyroid cancer; MTC, medullary thyroid cancer; FMTC, familial medullary thyroid cancer; MEN2, multiple endocrine neoplasia type 2.