A 17-year-old boy is brought to the clinic due to a breast mass. He first noticed pain beneath his right nipple a month ago, and over the last few weeks, the right breast has become enlarged. The patient has no chronic medical conditions and takes no medications. He is doing well in school, and family history is unremarkable. Height and weight are at the 75th percentile. Temperature is 37 C (98.6 F), blood pressure is 110/66 mm Hg, pulse is 100/min, and respirations are 20/min. Examination shows a prominent right breast with a palpable and tender, 5-cm, well-circumscribed mound deep to the right nipple. There is no axillary or cervical lymphadenopathy. Cardiopulmonary examination is unremarkable, and the abdomen is soft without tenderness. Examination of the external genitalia shows testes without a palpable mass. Sexual maturity rating (Tanner) is stage 5. Laboratory results are as follows: Which of the following is the best next step in evaluation of this patient?

Question

A 17-year-old boy is brought to the clinic due to a breast mass.  He first noticed pain beneath his right nipple a month ago, and over the last few weeks, the right breast has become enlarged.  The patient has no chronic medical conditions and takes no medications.  He is doing well in school, and family history is unremarkable.  Height and weight are at the 75th percentile.  Temperature is 37 C (98.6 F), blood pressure is 110/66 mm Hg, pulse is 100/min, and respirations are 20/min.  Examination shows a prominent right breast with a palpable and tender, 5-cm, well-circumscribed mound deep to the right nipple.  There is no axillary or cervical lymphadenopathy.  Cardiopulmonary examination is unremarkable, and the abdomen is soft without tenderness.  Examination of the external genitalia shows testes without a palpable mass.  Sexual maturity rating (Tanner) is stage 5.  Laboratory results are as follows:  Which of the following is the best next step in evaluation of this patient?

Quizplus · Accepted Answer

11ec25c8_d660_395a_bc81_1b1d1e5612eb_MD0003_00 Gynecomastia is abnormal growth of breast tissue in male patients. It generally results from an increased ratio of estrogens (which cause hyperplasia of breast ductal epithelium and fibrosis of stromal tissues) to androgens (which inhibit breast development). Besides rapidly progressive gynecomastia, this patient has a low to normal testosterone level, elevated estradiol, and a striking rise in β-hCG, which most commonly represents an hCG-secreting germ cell tumor of the testis. Excessive secretion of hCG by testicular germ cell tumors suppresses testosterone production in Leydig cells and increases aromatase activity and conversion of androgens to estrogens; the resulting increase in the estrogen/androgen ratio can cause gynecomastia. Even though this patient has a normal testicular examination, ultrasound is indicated to exclude an occult mass. (Choice A) Androgen receptor defects typically present at birth with female phenotype or ambiguous genitalia, although some variants (eg, partial androgen insensitivity syndrome) may present in adulthood with gynecomastia. However, patients typically have undervirilization (eg, decreased facial and pubic hair) and elevated serum LH. (Choice B) Breast imaging (eg, mammography, ultrasound) and biopsy are indicated for patients with suspected breast malignancy. Typical findings include a hard or nodular mass with an eccentric location. This patient's subareolar swelling and hormonal abnormalities make breast cancer unlikely; in addition, there is no family history of breast cancer to warrant considering genetic diseases that may result in early-onset breast cancer. Both physiologic (ie, pubertal) and pathologic gynecomastia can be unilateral or bilateral. (Choice C) Karyotype analysis is used to diagnose Klinefelter syndrome (47,XXY), a common cause of gynecomastia. However, patients typically have primary hypogonadism with small, firm testes; low serum testosterone; and elevated LH levels. (Choice D) Reassurance is appropriate for pubertal gynecomastia, a benign, physiologic condition caused by transiently increased testicular production of estrogen and peripheral conversion of prohormones to estrogen. It most commonly occurs at age 12-14 during midpuberty (Tanner stage 3-4), develops gradually, and resolves within a year. The onset of gynecomastia outside the pubertal range after sexual maturity warrants additional workup. Educational objective: Gynecomastia with abnormal features (eg, rapid progression, large size, occurrence outside pubertal age range) should include laboratory evaluation to assess for a pathologic cause. An increased β-hCG level in this setting is concerning for an hCG-secreting tumor, and a testicular ultrasound should be obtained.

A 17-Year-Old Boy Is Brought to the Clinic Due to a Breast