We're unable to sign you in at this time. Please try again in a few minutes.
We were able to sign you in, but your subscription(s) could not be found. Please try again in a few minutes.
There may be a problem with your account. Please contact the AMA Service Center to resolve this issue.
Contact the AMA Service Center:
Telephone: 1 (800) 262-2350 or 1 (312) 670-7827  *   Email: subscriptions@jamanetwork.com
Error Message ......
Article |

Apparent Isolated Elevation of Serum Triiodothyronine Level in a Patient With a Thyroid Nodule

Jacobo Wortsman, MD
Arch Intern Med. 1988;148(8):1866-1868. doi:10.1001/archinte.1988.00380080126032.
Text Size: A A A
Published online


• Cystic thyroid nodules most commonly occur with a euthyroid state and appear as cold lesions on radioactive iodine scan. I describe a 32-year-old woman who presented during the third trimester of her second pregnancy with a toxic cystic lesion of the thyroid. In studies performed post partum, the serum free thyroxine (T4) index was normal, while the triiodothyronine (T3) level was elevated and thyrotropin level was low and unresponsive to thyrotropin-releasing hormone stimulation. Iodine 123 thyroid scan demonstrated localized nonsuppressible uptake over the nodule. Multiple echo-free (fluid-filled) cavities were observed by ultrasound study. Thyroid lobectomy demonstrated a thyroid colloid nodule with areas of cystic degeneration containing hyperplastic papillary projections. Postoperatively, the patient developed transient hypothyroidism followed by spontaneous recovery to euthyroidism with normal function of the suppressed gland. Blood obtained from the venous effluent of the thyroid nodule had extremely high T3 and T4 concentrations: 359.1 nmol/L and 2420 nmol/L, respectively, while peripheral venous blood showed isolated elevation of T3, to 4.6 nmol/L (normal, 1.2 to 3.1 nmol/L), and a normal T4 level of 116 nmol/L (normal, 64 to 154 nmol/L). Serum T3 and T4 thyroidal/peripheral ratios were close to one in two euthyroid patients undergoing neck surgery. Thus, thyroid nodules may present with isolated elevation of serum T3 levels despite increased thyroidal release of T4.

(Arch Intern Med 1988;148:1866-1868)


Sign in

Purchase Options

• Buy this article
• Subscribe to the journal
• Rent this article ?





Also Meets CME requirements for:
Browse CME for all U.S. States
Accreditation Information
The American Medical Association is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The AMA designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 CreditTM per course. Physicians should claim only the credit commensurate with the extent of their participation in the activity. Physicians who complete the CME course and score at least 80% correct on the quiz are eligible for AMA PRA Category 1 CreditTM.
Note: You must get at least of the answers correct to pass this quiz.
Please click the checkbox indicating that you have read the full article in order to submit your answers.
Your answers have been saved for later.
You have not filled in all the answers to complete this quiz
The following questions were not answered:
Sorry, you have unsuccessfully completed this CME quiz with a score of
The following questions were not answered correctly:
Commitment to Change (optional):
Indicate what change(s) you will implement in your practice, if any, based on this CME course.
Your quiz results:
The filled radio buttons indicate your responses. The preferred responses are highlighted
For CME Course: A Proposed Model for Initial Assessment and Management of Acute Heart Failure Syndromes
Indicate what changes(s) you will implement in your practice, if any, based on this CME course.


Some tools below are only available to our subscribers or users with an online account.

1 Citations

Sign in

Purchase Options

• Buy this article
• Subscribe to the journal
• Rent this article ?

Related Content

Customize your page view by dragging & repositioning the boxes below.