MON-153 - Gynecomastia in A Male - Not Always Benign

Introduction
Gynecomastia in men is an enlargement of glandular breast tissue that results from an imbalance between estrogen and androgen activity in the breast. It is a common condition present in one-third to two-thirds of men on examination. Most cases of gynecomastia are idiopathic or physiologic occurring in newborns, adolescents and older men. Secondary causes include medications, chronic diseases (cirrhosis, renal insufficiency, hyperthyroidism), and rarely tumors.

Case presentation
We present the case of a 19-yr old post pubertal male with no significant past history who presented to the endocrine clinic for evaluation of gynecomastia. He reported normal axillary and pubic hair growth, normal libido, and normal shaving frequency. He denied headaches, vision changes, dizziness, breast tenderness, or discharge. Also denied taking any medications, supplements, as well as exogenous testosterone or alcohol use. He was overweight with a BMI of 27.2 kg/m2 (normal 18.5-24.9). Mammogram showed diffuse bilateral gynecomastia. Laboratory testing: normal CBC and CMP, elevated estradiol 70.72 pg/ml (normal =11.8-39.8), elevated total testosterone 1119ng/dl (normal 264-916), normal FSH 2.8 mIU/ml, normal LH 6.46 mIU/ml (normal 1.5-9.3), normal prolactin 7.5 ng/ml (normal 2.2-17.7), and negative serum beta HCG < 5mIU/ml. Further evaluation also showed elevated free testosterone 203.1 pg/ml (normal 35-155), normal TSH 1.129 uIU/ml (normal 0.550-4.780), FT4 1.15 ng/dl (normal 0.89-1.76), ACTH 17 pg/ml (normal 0-47), cortisol 7.55 ug/dl, DHEAS 267.68 ug/dl (normal 34.5-568.9) and 17 hydroxyprogesterone 130 ng/dl (normal 32-307). US scrotum- small left epididymal cyst. CT of the adrenal gland was done which revealed a 0.7 x 0.6 cm left adrenal nodule, measuring approximately 32 Hounsfield units (HU) on pre-contrast sequence, 64 HU on portal venous phase, and 54 HU on the 15-minute delayed sequence corresponding to absolute washout of approximately 31% and relative washout of approximately 16%, indicative of an indeterminate nodule. Since the nodule was >10 HU and washout < 50%, there was concern for adrenocortical carcinoma vs early pheochromocytoma.

Discussion
Our case highlights that although gynecomastia is generally considered a benign finding in most cases, especially in young men, it is important to order an extensive evaluation to rule out pathologic causes, especially for malignancy in hormone-producing testicular and/or adrenal tumors. Adrenocortical carcinoma is a rare but aggressive malignancy that requires urgent surgical intervention making early detection crucial. Data suggests that gynecomastia may also be a sentinel finding in some adrenal tumors, making thorough evaluation for early diagnosis and treatment essential for a good prognosis.

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