I am going to answer the sample USMLE Step 1 Questions with Explanation. These questions are available at USMLE.org
Q- An 11-year-old girl is brought to the emergency department by her parents because of a 1-week history of breast enlargement. She has not had pain or nipple discharge. She has asthma treated with inhaled albuterol as needed. She does not smoke cigarettes, drink alcoholic beverages, or use illicit drugs. She is at the 50th percentile for height and weight. Vital signs are within normal limits. Examination of the breasts shows minimal enlargement under the areolae and mild enlargement of the diameter of the areolae without nipple discharge; no masses are palpated. There is scant pubic hair. Which of the following best describes the sexual maturity rating for this patient?
(A) 1
(B) 2
(C) 3
(D) 4
(E) 5
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Answer and Explanation
This 11-year-old girl presents with minimal breast enlargement under the areolae and mild enlargement of the areolar diameter, without masses or nipple discharge. She also has scant pubic hair. These findings are consistent with Sexual Maturity Rating (Tanner stage) 2.
Tanner Staging for Breast Development:
- Stage 1: Prepubertal (no breast tissue)
- Stage 2: Breast budding (small mound formation under the areola; enlargement of areolar diameter)
- Stage 3: Further enlargement of the breast and areola without separation of contours
- Stage 4: Projection of the areola and nipple to form a secondary mound
- Stage 5: Mature adult breast (areola returns to breast contour, nipple projects)
Tanner Staging for Pubic Hair:
- Stage 1: No pubic hair
- Stage 2: Sparse, fine, downy hair along the labia
- Stage 3: Darker, coarser, more curled hair extending over the pubis
- Stage 4: Adult-like hair covering a smaller area
- Stage 5: Adult distribution, extending to the thighs
The correct answer is B