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. 2022 Jul-Sep;18(3):398-400.
doi: 10.4183/aeb.2022.398.

GYNAECOMASTIA APPEARED THREE DAYS AFTER STARTING METHIMAZOLE

Y Chen  1 , M Zhao  1 , X Hu  1 , H Yao  1
Affiliations

GYNAECOMASTIA APPEARED THREE DAYS AFTER STARTING METHIMAZOLE

Y Chen et al. Acta Endocrinol (Buchar). 2022 Jul-Sep.

Abstract

We reported that in a 29-year-old male patient with hyperthyroidism, bilateral breast swelling appeared in three days after starting methimazole and gradually aggravated. Several days later, a small amount of transparent liquid could be squeezed out from bilateral mammary glands. Breast ultrasound confirmed gynaecomastia. The level of testosterone, estradiol and luteinizing hormone increased. After the patient continued taking methimazole for a while, gynaecomastia relieved. Testosterone, luteinizing hormone and thyroid functions restored to normal. The possible mechanisms included increased levels of serum total cholesterol and relatively decreased T3 after initiating methimazole.

Keywords: gynaecomastia; hyperthyroidism; methimazole; testosterone.

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Conflict of interest statement

The authors declare that they have no conflict of interest.

Figures

Figure 1
Figure 1
Ultrasound images of right breast on November 13th , 2019.
Figure 2
Figure 2
Ultrasound images of left and right breasts on January 9th 2020.
See this image and copyright information in PMC

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