A 15-year-old girl is found to have an ectopic endometrial tissue causing abdominal pain. Which organ should be evaluated for such tissue?

In the context of ectopic endometrial tissue, particularly in a 15-year-old girl experiencing abdominal pain, it is important to focus on structures that are commonly associated with endometriosis. Meckel diverticulum is a remnant of the embryonic yolk sac and can have ectopic endometrial tissue implanted within it, particularly in females.

Ectopic endometrial tissue is often found in the pelvic region, commonly affecting the ovaries, fallopian tubes, and peritoneum, but it can also manifest in atypical locations like the gastrointestinal tract. Since Meckel diverticulum is identified as a location where endometrial tissue could be found, it is the most relevant organ to be evaluated in this scenario. The other options (falciform ligament, vermiform appendix, ascending colon) do not typically serve as sites for ectopic endometrial tissue and are therefore less relevant in this case.

In essence, evaluating the Meckel diverticulum makes sense as it can house ectopic endometrial tissue and is associated with potential abdominal pain, particularly in adolescent girls.