Well-differentiated
thyroid cancer accounts for 95% of thyroid
malignancies. In contrast to medullary
thyroid carcinoma, in which about 25% are familial, only 5% of follicular cell-derived
thyroid carcinomas are a component of a familial
cancer syndrome. The familial follicular cell-derived
tumors or
nonmedullary thyroid carcinoma encompass a heterogeneous group of diseases, and are classified into 2 distinct groups: syndromic-associated
tumors, occurring in syndromes in which
nonmedullary thyroid carcinomas are the predominant
tumor encountered, and nonsyndromic
tumors, those occurring in
tumor syndromes in which thyroid involvement is a minor component. The first group, syndromic-associated
tumors, includes phosphase and
tensin (
PTEN)-hamartoma tumor syndrome/
Cowden syndrome,
familial adenomatous polyposis/
Gardner syndrome,
Carney complex type 1,
Werner syndrome, and
Pendred syndrome. Other syndromes, as
McCune Albright syndrome,
Peutz-Jeghers syndrome, and
Ataxia-teleangiectasia syndrome may be associated with the development of follicular cell-derived
tumors, but the link is less established than the above syndromes. The syndromic-associated
tumors are the focus of this review. The second group of familial follicular cell-derived
tumors syndromes or nonsyndromic
tumors, in which
nonmedullary thyroid carcinomas are the major findings, include pure familial
papillary thyroid carcinoma, with or without oxyphilia, familial
papillary thyroid carcinoma with
papillary renal cell carcinoma, and familial
papillary thyroid carcinoma with multinodular
goiter. This review will discuss the clinical and pathological findings of the patients with familial syndrome-associated
tumors:
PTEN-hamartoma tumor syndrome/
Cowden syndrome,
familial adenomatous polyposis syndrome, Carney complex type 1,
Werner syndrome, and
Pendred syndrome.