Metastatic Pure Papillary Thyroid Carcinoma Presenting as a Toxic Hot Nodule

Abstract

In the majority of cases, carcinoma of the thyroid presents as a cold nodule by radioiodine and Tc-99m sodium pertechnetate scintigraphy. Whereas the presence of a hot nodule usually implies a benign entity, it does not provide complete assurance against thyroid malignancy. Presented is a rare case of metastatic pure papillary thyroid carcinoma appearing as a hot nodule on Tc-99m sodium pertechnetate and I-123 sodium iodide scintigraphy. The implications of such a case, its management, and review of the pertinent literature are discussed.

Does a Leu 512 Arg Thyrotropin Receptor Mutation Cause an Autonomously Functioning Papillary Carcinoma?

“…Most thyroid nodules are benign and according to scintigraphic findings; thyroid nodules are classified as hot, cold or warm (2,21). A hot nodule is most frequently caused by a follicular adenoma and is rarely associated with malignancy (2).…”

“…A hot nodule is most frequently caused by a follicular adenoma and is rarely associated with malignancy (2). There are only some case reports in the literature (10)(11)(12)(13)(14)(15)22).…”

“…Thyroid nodules have been classified by radioiodine scintigraphy used either 123 I or 99m Tc as cold, hot, or warm depending on the amount of activity in the nodule compared to the rest of the thyroid tissue (2,3). Scintigraphically, 80%-90% of thyroid nodules have diminished uptake and they are called cold nodules (3).…”

“…It is increased to 20% if the nodule is cold or warm and decreased to 1% or less if it is hot (4). Because of this low incidence of cancer in hot nodules, further evaluation is not indicated unless there are features suggesting malignancy (2).…”

Thyroid Carcinoma in Hot Nodules: Review of the Literature

“…Out of these 31 articles, 16 articles (five series of cases and 11 case reports) included cases matching the previously mentioned criteria for a total of 45 reported cases. 6,7,[11][12][13][14][15][16][17][18][19][20][21][22][23][24] Among these 45 cases, the histological repartition was as follow: 25 (56%) follicular carcinoma, 16 (36%) papillary carcinoma including at least four (9%) confirmed follicular variant, two (4%) Hürthle cells thyroid cancer, one (2%) poorly differentiated thyroid cancer and we were not able to find the histology for one case (Table 1).…”