A 25-year-old woman presents to the Emergency Department with a 2-hour history of pelvic pain...

Comprehensive and Detailed Explanation:

Mid-cycle acute onset pelvic pain with localized adnexal tenderness in a reproductive-age woman suggests a hemorrhagic ovarian cyst, particularly a ruptured one. The hemodynamic parameters are stable, but elevated HR supports acute pain and possible blood loss.

Toronto Notes 2023 – Gynecology / Acute Pelvic Pain:

“Hemorrhagic ovarian cysts present with sudden unilateral pelvic pain, mid-cycle, with guarding and rebound tenderness. Ultrasound is key.”

MCCQE1 Objectives (Gynecology > 82-4: Acute Pelvic Pain):

“Candidates must recognize common causes of acute pelvic pain, including ovarian cysts.”

Diverticulitis (A) is rare in young women and usually LLQ. Appendicitis (B) is more likely RLQ. Adenomyosis (C) and endometriosis (D) cause chronic cyclical pain, not acute tenderness.

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