Review Question - QID 104579

A 45-year-old with a cold nodule and follicular architecture is suspicious for follicular adenoma or adenocarcinoma. A surgical excision is necessary to determine whether the neoplasm exhibits signs of capsular or vascular invasion for this determination.

Thyroid nodules are a common finding on physical exam and can be palpated in 4 to 7% of all adults. Thyroid hormones T4 and T3 largely control Na+/K+ ATP-dependent transporters, the energy consumers of our cells. As a result, fluctuation in these hormones can cause people to present with weight loss or weight gain, heat or cold intolerance, and palpitations or fatigue, based on whether these levels are high or low (respectively). All thyroid nodules should be evaluated for malignancy first by radionucleotide scan and then by FNAB if these nodules are not hyperactive (i.e. "cold").

Knox discusses guidelines for diagnosis and treatment for thyroid nodules. He notes that while benign nodules are common, history of head or neck radiation, old age, chronic thyroid disease (like Graves), and family history (MEN 2A/2B) can cause an increase in risk of future thyroid carcinoma. He also notes that most malignant nodules are not hyperfunctioning (on radionucleotide scan), and should undergo FNAB. If FNAB is suspicious for malignancy, a thyroidectomy should be performed for evaluation due to risk of carcinoma.

Sugino et al. discuss the prognostic factors relating to follicular thyroid carcinoma with distant metastases. They report that the survival rate for their cohort at 5, 10, and 15 years after the first distant metastases was diagnosed were 82%, 64%, and 24%, respectively. They also noted that increasing age at diagnosis of the metastasis and primary tumor size were factors significantly associated with a decrease in survival rates.

Illustration A shows follicular architecture in the thyroid gland, and can be either adenoma or adenocarcinoma as distinguished by capsular and vasculature invasion upon surgical resection. Illustration B shows an algorithmic approach to thyroid nodules.

Incorrect Answers:
Answer 1: A punch biopsy will not add information of invasion so it is not useful for this patient.

Answer 3: The patient my require thyroxine over the long-term but it is not the next best step.

Answer 4 and 5: The patient already has a biopsy result suspicious for malignancy and currently has no other complaints. Thus, no further imaging is required.