EAA clinical practice guidelines-gynecomastia evaluation and management.

S1. Gynecomastia (GM) is a benign proliferation of glandular tissue of the breast in males. S2. GM of infancy is a common condition that usually resolves spontaneously, typically within the first year of life. S3. GM of puberty is a common condition, affecting approximately 50% of mid-pubertal boys; in more than 90% of cases, it resolves spontaneously within 24 months. S4. The prevalence of GM in adulthood increases with increasing age; proper investigation may reveal an underlying pathology in approximately 45-50% of the cases. S5. Male breast cancer is rare; GM should not be considered a premalignant condition. The following recommendations are divided into 'strong', denoted by the number 1 and associated with the terminology 'we recommend', and 'weak' denoted by the number 2 and associated with the phrase 'we suggest'. The grading of the quality of evidence is denoted as follows: ⊕○○○ for very low-quality evidence; ⊕⊕○○ for low quality; ⊕⊕⊕○ for moderate quality; and ⊕⊕⊕⊕ for high quality. R1. The presence of an underlying pathology should be considered in GM of adulthood. We recommend that the identification of an apparent reason for GM in adulthood, including the use of medication known to be associated with GM, should not preclude a detailed investigation (1 ⊕⊕⊕○). R2. We suggest that the initial screening to rule out lipomastia, obvious breast cancer, or testicular cancer might be performed by a general practitioner or another non-specialist (2 ⊕○○○). R3. We recommend that in those cases where a thorough diagnostic workup is warranted, it should be performed by a specialist (1 ⊕○○○). R4. We recommend that the medical history should include information on the onset and duration of GM, sexual development and function, and administration or abuse of substances associated with GM (1 ⊕⊕⊕○). R5. We recommend that the physical examination should detect signs of under-virilization or systemic disease (1 ⊕⊕⊕⊕). R6. We recommend that breast examination should confirm the presence of palpable glandular tissue to discriminate GM from lipomastia (pseudo-gynecomastia) and rule out the suspicion of malignant breast tumor (1 ⊕⊕⊕⊕). R7. We recommend that the physical examination should include the examination of the genitalia to rule out the presence of a palpable testicular tumor and to detect testicular atrophy (1 ⊕⊕⊕⊕). R8. We recommend that genitalia examination is aided by a testicular ultrasound, as the detection of a testicular tumor by palpation has low sensitivity (1 ⊕⊕○○). R9. We suggest that a set of evaluations may include T, E2 , SHBG, LH, FSH, TSH, prolactin, hCG, AFP, and liver and renal function tests (2 ⊕⊕○○). R10. We suggest that breast imaging may offer assistance, where the clinical examination is equivocal (2 ⊕⊕○○). R11. We suggest that, if the clinical picture is suspicious for a malignant lesion, core needle biopsy should be performed (2 ⊕⊕○○). R12. We recommend watchful waiting after treatment of underlying pathology or discontinuation of the administration/abuse of substances associated with GM (1 ⊕⊕○○). R13. We recommend that T treatment should be offered only to men with proven testosterone deficiency (1 ⊕⊕⊕○). R14. We do not recommend the use of selective estrogen receptor modulators (SERMs), aromatase inhibitors (AIs), or non-aromatizable androgens in the treatment of GM in general (1 ⊕⊕○○). R15. We suggest surgical treatment only for patients with long-lasting GM, which does not regress spontaneously or following medical therapy. The extent and type of surgery depend on the size of breast enlargement, and the amount of adipose tissue (2 ⊕⊕○○).