IPLab:Lab 7:Adenoma

Clinical Summary

This 80-year-old white female's death came as the result of cardiopulmonary disease -- hypertension, coronary artery disease, pulmonary emphysema and cardiac hypertrophy.

Autopsy Findings

During a routine postmortem examination, this patient's thyroid gland was found to be nodular. The right lobe contained several colloid nodules. Located in the left lobe was a 2-cm well-circumscribed mass.

Images

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  This is a low-power photomicrograph of a nodule found in the thyroid of this case. Note that the mass is well-circumscribed and there is a sharp line of demarcation between the mass and the adjacent thyroid tissue (arrows).

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  This is a higher-power view of the border between the tumor mass and the adjacent thyroid tissue. Note that the mass has compressed the adjacent normal thyroid tissue (arrow). Also note the different morphology between the adenoma (very cellular, dense follicles, little or no colloid) and the adjacent normal thyroid (larger follicles, colloid).

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  This is another higher-power photomicrograph of the adenoma (left) and the adjacent thyroid tissue (right). Note the compression of the adjacent normal thyroid and the difference in morphology between the adenoma and the thyroid.

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  This photomicrograph demonstrates the densely packed follicular pattern in the adenoma (left) and the larger colloid-filled follicles of the normal thyroid (right). An area of compressed thyroid is present adjacent to the adenoma (arrows).

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  This is a photomicrograph of an adenoma. Note that the follicular architecture is well developed and more or less uniform throughout this section.

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  This high-power photomicrograph demonstrates the relatively normal cellular morphology of this follicular adenoma.

Study Questions

• What is the likelihood that this tumor would have been 'hot' or would have taken up radioactive iodine?

Benign tumors are more likely to take up radioactive iodine than malignant tumors.

• What are the differential diagnoses for thyroid masses?

Goiter, adenomas, neoplastic tumors of the thyroid.

• Although usually asymptomatic, what important clinical problems can occur in patients with benign thyroid adenomas?

They may:

1. increase in size and cause pressure symptoms in the neck,
2. achieve a certain size and then plateau,
3. suddenly enlarge and become painful owing to intralesional hemorrhage, and
4. rarely synthesize T3 or T4 and cause hyperthyroidism that is usually mild and unassociated with ophthalmopathy.

• Is someone with a thyroid adenoma at risk for thyroid carcinoma?

No. The risk of malignant transformation is almost negligible.

Additional Resources

Reference

• eMedicine Medical Library: Evaluation of Solitary Thyroid Nodule
• eMedicine Medical Library: Thyroid Nodule

Journal Articles

• Tonacchera M, Vitti P, Agretti P, Ceccarini G, Perri A, Cavaliere R, Mazzi B, Naccarato AG, Viacava P, Miccoli P, Pinchera A, Chiovato L. Functioning and nonfunctioning thyroid adenomas involve different molecular pathogenetic mechanisms. J Clin Endocrinol Metab 1999 Nov;84(11):4155-8.