Endocrine Abstracts

Case Description: A 66-year-old lady with a past surgical history of partial left lobectomy for unclear reasons 30 years ago was referred by the surgeon for evaluation of thyroid nodules. She reported noticing palpable neck masses but didn’t report associated heat/cold intolerance, palpitations, diarrhea, tremor, fatigue, skin/hair /sleep /weight/appetite changes. No associated neck pain, dysphagia, fever, upper respiratory tract infection symptoms, or vaccination. No obstructive symptoms reported. No recent Biotin, herbal or over-the-counter remedies. No similar complaints in the past and no family history of thyroid disorders. There was no radiation exposure in the past. Medications include Aspirin 81 mg, and Olmesartan-amlodipine-HCTZ. She is postmenopausal. No smoking/alcohol/recreational drugs. Vitals normal and BMI 22.7 Physical examination is significant for two right-sided rubbery, non-tender, mobile masses in the right upper neck and palpable right thyroid nodules.

Investigations: The biochemical evaluation revealed normal CBC, CMP. -TSH 1.33IU/mL, FT4 1.06ng/dl -Thyroid US: two thyroid nodules 20x19x13mm, 9x8x7mm and several small nodules in right lobe and one Right mid jugular chain lymph node -US Neck mapping: R level III mid jugular: three lymph nodes measuring 4-5 mm, no fatty hila, other levels and left side are normal -Lymph node Excisions of two right cervical lymph nodes showed fragments of benign thyroid tissue; no lymphoma, however flow cytometry couldn’t be performed due to lack of significant lymphoid population. -Thyroseq molecular test from the lymph nodes samples obtained was negative for genetic mutation -Repeat Thyroid US- Stable thyroid nodules -Repeat TFT after 2 months, TSH 2.180IU/mL, FT4 1.00ng/dl remained clinically and biochemically euthyroid.

Discussion: Ectopic thyroid tissue (ETT) is a rare phenomenon and usually occurs along the normal path of thyroid descent. There have been reports of thyroid tissue found in places such as the abdominal organs, pelvis, axilla, and thoracic cavity. It is, however, rare to find thyroid tissue within lateral neck masses. When thyroid tissue is found in a cervical lymph node, the suspicion of nodal metastasis of differentiated carcinoma of the thyroid should be high. In our case, FNAB of thyroid nodules, excision biopsy of lymph nodes, and a Thyrosequence molecular test were negative for malignancy. Our hypothesis is that in our patient with a previous history of thyroid surgery, the seeding of cells from thyroid tissue may be the possible mechanism.