Definition
- Diffuse hyperplastic goiter with symmetric enlargement of the gland (goiter is a generic term that refers to enlargement of the thyroid gland).
- Characteristic ophthalmopathy (proptosis, upper lid lag and retraction, periorbital edema) in most patients
- Characteristic dermopathy (10-15% of cases), appearing as plaque-like or nodular areas of edema on the backs of the legs and feet
- Because the orbital and skin changes are not present in all cases, symmetric goiters with hyperthyroidism (as measured by increased iodine uptake) and thyrotoxicosis are generally presumed to indicate Grave's disease.
- Occurs in 1-2% of women, less often in men, more common with certain HLA haplotypes, autoimmune mechanism (also accounts for the ophthalmopathy and dermopathy)
- Thyroid-stimulating antibodies produced as a part of the autoimmune reaction, bind to the TSH receptor and mimic the action of TSH.
Case Study
A 27 year old female presented with a history of nervousness, palpitations and heat intolerance. Her
heart rate was 105 and bowel sounds were hyperactive. The skin was moist.
TSH was undetectable in a 3rd-generation immunoassay. Free T4 was 7.5 ng/dl (0.8-2.3)
Thyroid uptake of radioactive iodine was substantially increased overall (172% of normal), but there is also a "cold nodule" (a localized area of decreased iodine uptake) in the lower right pole of the gland.
The thyroid gland was removed and pathologic examination showed diffuse hyperplasia with folded follicles and hypermetabolic cells. Note the white bubbly appearance of the edge of the colloid that borders the cells. This indicates active colloid resorption.
Sections in the area of the lower right pole showed a discrete mass that was determined to be a follicular adenoma on microscopic exam.
Final Diagnosis: Grave's Disease with a hyperplastic thyroid gland and an incidental Follicular Adenoma