A 67-year-old postmenopausal woman with hirsutism of increased hair around the upper lip and armpit and clitoromegaly for five months was referred to the endocrinology clinic of our hospital. She had normal physiological development during her infancy and childhood, and also has a normal sexual life with no other medical history. Her menarche was at 18 years old, and her menopause at age of 56. She had a normal menstrual history before menopause and had no postmenopausal bleeding. She had two healthy children and no miscarriages. She denied taking estrogen, progesterone or health care products. There are no similar patients in her family. On physical examination, she was 153 cm tall and weighed 53 kg with body mass index of 22.6 kg/m2. Increased hair was observed in her upper lip and armpit (Ferriman- Gallwey score of 8), and a physical examination of genital revealed clitoromegaly. There was no acne, deepening of the voice or other virilization signs. Findings on examination of the head and neck, breasts and abdomen were unremarkable. She had no signs of Cushing syndrome, or acanthosis nigricans syndrome. The hormonal test showed high total testosterone levels (714.8 ng/dL, reference value 14–56). Serum DHEAS (145.8 ng/mL, reference value 25.9–460.2), androstenedione (2.4 ng/mL, reference value 0.3–3.3) and 17-hydroxyprogesterone (1.7 nmol/l, reference value 0–11.5) levels were within normal range. The serum values of follicle-stimulating hormone, luteinizing hormone, and prolactin were also within the normal range for the menopause. The levels of anti-mullerian hormone, human chorionic gonadotropin (hCG), thyroid- stimulating hormone (TSH), plasma renin activity and aldosterone, adrenocorticotropic hormone (ACTH), serum cortisol, 24-h urinary free cortisol, and 1 mg dexamethasone suppression test were in normal range. The ovarian tumor markers (Ca 125, CEA, Ca 199) were in normal reference range. The repeated samples confirmed that her high testosterone levels were within the tumor range. We excluded overt Cushing Syndrome on the basis of normal cortisol suppression after 1 mg dexamethasone and normal urinary free cortisol levels, as recently proposed by Ceccato F []. Then a middle dosage dexamethasone test (0.75 mg, 4 times a day for 5 consecutive days) without testosterone inhibition strongly suggested the potential androgen-producing tumor, further examinations were needed to distinguish ovarian or adrenal origin of hyperandrogenemia. Initially, the lack of co-secretion of DHEAS and androstenedione indicated that her elevated testosterone might be of ovarian origin. However, pelvic ultrasound disclosed that there was no ovarian mass, while adrenal ultrasound showed a hypoechoic nodule in the left adrenal gland. Further pelvic magnetic resonance image (MRI) showed submucous myoma of uterus, but no abnormal of ovarian, and adrenal CT scan was also performed and a left adrenal mass of about 1.5 cm in diameter was revealed. PET-CT confirmed a round nodule in the external branch of the left adrenal gland with slight increase in FDG metabolism (the SUV max of the nodule was 2.56), considering the possibility of benign adenoma. No ovarian abnormalities or other ectopic tumors were found by PET-CT. Based on the clinical characteristics, hormone detection and imaging appearances of the case, pure testosterone-secreting adrenal tumor was suspected. Subsequently, the patient underwent a laparoscopic resection of left adrenal tumor. Histological examination and immunohistochemistry also confirmed the diagnosis of benign adrenocortical adenoma with immunohistochemistry positive for inhibin α, melan A, β-captenin, SYN (focal), Ki-67 (< 3%), and negative for chromogranin (CgA), cytokeratin (CK), S-100, P53. The level of testosterone decreased to 15.8 ng/dl on the 3rd day after operation, and the symptoms of virilization were alleviated during the follow-up, which further confirms the adrenal etiology of the testosterone production.