A 55-year-old postmenopausal woman on tamoxifen for breast cancer for 4 years presents with vaginal spotting. Transvaginal ultrasound shows an endometrial thickness of 18 mm with a heterogeneous, cystic appearance. What is the characteristic ultrasound finding associated with tamoxifen-related endometrial pathology?
- A Subendometrial cystic thickening with a thin echogenic endometrium ✓
- B Smooth, homogeneous endometrial thickening
- C A discrete intracavitary polyp with a feeding vessel on Doppler
- D Diffuse uterine enlargement with heterogeneous myometrium
Correct answer: A. Subendometrial cystic thickening with a thin echogenic endometrium
Explanation
Tamoxifen causes a characteristic subendometrial cystic thickening on ultrasound due to its oestrogenic effect on the endometrium, with the endometrium appearing thin and echogenic over subendometrial oedema and cystic atrophy. This finding can mask true endometrial pathology. Endometrial biopsy is essential when bleeding occurs regardless of thickness on tamoxifen. Smooth homogeneous thickening is typical of simple hyperplasia. B discrete polyp may be seen but is not the characteristic tamoxifen pattern.
Reference: Williams Gynecology, 4th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.