A 6-month-old boy with bilateral breast enlargement

A 6-month-old boy was referred to our clinic with a 4-month history of progressive bilateral breast enlargement (figure 1). There was no history of maternal medication, infection, trauma, nipple discharge, contact with oestrogen products or familial breast disorder. He had bilateral painless breast enlargement without nipple discharge and signs of inflammation. His testes were both palpable in the scrotum, measuring 2 mL in volume. Figure 1 General appearance of the patient. There were no signs of other endocrine abnormalities. 1. From the patient's clinical presentation, what is the most likely diagnosis? 1. Prepubertal gynaecomastia 2. 46,XX disorder of sex development 3. 17α-hydroxylase deficiency 4. 46,XY disorder of sex development 5. Breast abscess 2. Other than breast ultrasound, which investigation(s) would you perform (multiple answers are possible)? 1. Whole blood count and erythrocyte sedimentation rate 2. Prolactin, total testosterone and oestradiol 3. Free thyroxine, thyroid stimulating hormone (TSH) and cortisol 4. Human chorionic gonadotropic hormone 5. Karyotype …