Not true about gynecomastia is
Gynaecomastia is hypertrophy of male breast more than usual due to increase in ductal (epithelial) and connective tissue (stromal) elements often attaining features of the female breast. 
It can be unilateral or bilateral. Bilateral can be symmetrical or asymmetrical.
Etiology is 
Oestrogen excess—increased estradiol secretion due to a testicular tumour (Leydig cell) or nontesticular tumours from the adrenal cortex, lung, liver; hyperthyroidism (increases conversion of androgen to estrogen), liver diseases, oestrogen therapy for prostate cancer.
Androgen deficiency—aging, Klinefelter’s/Kallmann syndromes, a eunuch, ACTH deficiency. 
Secondary testicular failure—cryptorchidism, orchitis, trauma, CRF, etc. 
Drugs (25%): Increases estrogen activity (digitalis, anabolic steroid)/estrogen synthesis (reserpine, theophylline, frusemide).  
Inhibition of testosterone synthesis—cimetidine, phenytoin, spironolactone.
Can be drug induced
Klinefelter's syndrome
Seen in cryptoorchidism
None of the above