A patient presents with postmenopausal bleed. Endometrial biopsy will be done if endometrial thickness is:
**Core Concept**
Endometrial thickness is a vital parameter in assessing postmenopausal bleeding. Endometrial thickness greater than 4-5 mm on ultrasound is considered abnormal and warrants further investigation, such as endometrial biopsy, to rule out endometrial cancer or hyperplasia.
**Why the Correct Answer is Right**
The American College of Obstetricians and Gynecologists (ACOG) recommends endometrial biopsy in postmenopausal women with an endometrial thickness greater than 5 mm. This is because the risk of endometrial cancer increases with increasing endometrial thickness. The endometrium is composed of two layers: the functional layer (stratum functionalis) and the basal layer (stratum basalis). The basal layer is thicker and more cellular, and it is from this layer that endometrial cancer often arises.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not provide a specific and universally accepted threshold for endometrial thickness. Different studies and guidelines may suggest different thresholds, but 5 mm is a commonly cited value.
**Option B:** This option is incorrect because it is too low. An endometrial thickness of 3-4 mm may be seen in some postmenopausal women without any pathology, and endometrial biopsy may not be necessary in this case.
**Clinical Pearl / High-Yield Fact**
Remember the "5 mm rule" for postmenopausal bleeding: if the endometrial thickness is greater than 5 mm on ultrasound, consider endometrial biopsy to rule out endometrial cancer or hyperplasia.
**Correct Answer: C.**