Postpartum Multinodular Goiter

Thyroid gland enlargement is a known phenomenon during pregnancy in iodine deficient countries. However, in iodine replete countries such as the United States, this is a rare occurrence.

Case Description :

A 36-year-old female singer with history of Multinodular Goiter presented to Endocrine clinic for evaluation secondary to dyspnea. Per patient, during her first two pregnancies her thyroid enlarged and returned to normal postpartum. However, this pattern did not continue following her third pregnancy. (Figure 1) She reported worsening dyspnea when lying flat, talking, and with physical exertion. She reported no medications, but infrequently took Vitamin D, Zinc, and Iron supplements. Physical examination was notable for an enlarged non tender goiter with intermittent palpable nodules. Thyroid ultrasound revealed a markedly enlarged and heterogenous thyroid gland with right lobe measurement of 10.6 x 4.9 x 4.1 cm and left lobe measurement of 12.0 x 7.0 x 5.3 cm in sagittal by AP by transverse dimension. Multiple nodules were also noted. Patient reported prior benign fine needle aspiration. Laboratory results were within normal limits, including her TSH and thyroid antibodies. Following surgical consultation, patient underwent total thyroidectomy. Post thyroidectomy, pathology revealed a benign multinodular goiter, weighing 434 grams (Figure 2), the largest lobe measuring 9.0 x 8.0 x 6.0 cm and the smallest lobe 7.0 x 5.0 x 4.0 cm, with largest nodule measuring 7.5 x 6.0 x 3.0 cm. The patient tolerated the procedure well and continued to enjoy her hobby of singing.

Discussion :

This case demonstrates the development of postpartum multinodular goiter in a young female. The development of new thyroid nodules or enlargement of existing ones can be seen during pregnancy and it can predispose development of multinodular goiter in later life.

Perhaps in this patient with a prior history of thyroid disease a higher dose of iodine supplementation should have been instituted. There is the need for further research on the efficacy and safety of iodine supplementation in pregnant women especially those with history of thyroid disease.