Case #1 Answers:
Answer 1
Further historical points to obtain in this patient include any recent
pregnancies, as hyperthyroidism may be due to postpartum thyroiditis. It
would also be important to know if the patient had experienced any
tenderness over her thyroid area in the last few weeks, suggestive of
subacute thyroiditis. While the patient denied iodine exposure, she may be
unaware of iodine in her multivitamins, over-the-counter cold preparations,
or in any dye procedures. This information is usually obtained by specific
questioning for these events.
Answer 2
The presence of a thyroid bruit would be important in this thyrotoxic
patient. An enlarged spleen should also be checked for in addition to
thyroid dermopathy of her lower extremities.
Answer 3
The next test that would be most appropriate in this patient would be a
24-hour iodine uptake. This test would be elevated if her hyperthyroidism
were secondary to Graves' disease as it appears, but would be very low if
she had underlying thyroiditis. The fact that her thyroid gland is diffusely
enlarged and normal in consistency mitigates against other causes of
hyperthyroidism such as exogenous levothyroxine abuse or over treatment ,
toxic multinodular goiter, hot nodule, exogenous thyroxine ingestion, or
struma ovarii. Her suppressed TSH argues against a TSH-producing pituitary
tumor.
Answer 4
Treatment options for this patient depend on the status of her uptake. If
her uptake is increased and thus consistent with underlying Graves' disease
as her clinical picture suggests, then options include thianomides to block
thyroid hormone synthesis, I131 ablation and surgery. Of these options
surgery is rarely performed, thus leaving the patient with two options of
drugs vs. I131. Each of these options should be discussed in detail with the
patient. Specifically, it should be explained to the patient that if she
chooses thianomides, she will need to take these medications for at least
one year and quite possibly two to three years and the side-effects of these
drugs should be explained, especially the rare problem with agranulocytosis.
If the patient chooses I131 therapy, then she should be informed of the
possibility that her eyes may become more proptotic, and that long-term data
examining the effects of I131 on future children have not been carried out
longer than fifteen years. As she is relatively young, she may opt for
thianomides at this point.