Endocrine Pathology Online
Pathology of Papillary Carcinoma originating in Hashimoto's Thyroiditis
Hashimoto's thyroiditis is an inflammatory disease of the thyroid gland with
Patients afflicted with Hashimoto's have a higher risk of thyroid malignancies such
as papillary thyroid carcinoma.
The presence of coexistent Hashimoto's thyroiditis does not affect the diagnostic
evaluation or management of papillary thyroid cancers.
The survival of patients who have papillary thyroid cancers may be superior in
coexistent Hashimoto's thyroiditis.
Neoplastic transformation is a multistep process that results in a continuous spectrum
from the normal (physiological) state to a fully established neoplasm.
The gold standard for diagnosis of papillary thyroid carcinoma is conventional
histology, the essential element being the characteristic nuclear features, regardless
of whether papillary structures are present or not.
However, other criteria are being used increasingly in the diagnosis of neoplasms,
including immunohistochemical staining and molecular profile.
The RET/PTC gene rearrangement is highly specific for papillary thyroid carcinoma
and is associated with the characteristic nuclear features seen in papillary
There is an overlap in the morphological features, immunohistochemical staining
pattern, and most importantly, molecular profile between papillary thyroid carcinoma
and Hashimoto's thyroiditis.
Although considered a 'benign' condition, Hashimoto's thyroiditis almost always
harbours a genetic rearrangement that is strongly associated with and is highly
specific for papillary thyroid carcinoma.
Lymphocytic infiltration with germinal centre formation leading to follicular
epithelial damage as evidenced by Hurthle cell metaplasia support the diagnosis
of Hashimoto's thyroiditis.
Copyright © 2017 histopathology-india.net