Endometrial Adenocarcinoma
The endometrial biopsy is most likely to show adenocarcinoma (option e), as this postmenopausal woman presents with the classic triad of vaginal bleeding, thickened endometrium on ultrasound, and malignant cells on cytology—all hallmark features of endometrial carcinoma. 1, 2
Clinical Reasoning
This case demonstrates the pathognomonic presentation of endometrial cancer:
- Postmenopausal bleeding occurs in approximately 90% of endometrial carcinoma cases, making it the cardinal presenting symptom 1, 2
- The presence of malignant cells in vaginal discharge cytology is diagnostic of malignancy, and in the context of thickened endometrium, this points directly to endometrial adenocarcinoma 3
- Approximately 75% of endometrial adenocarcinomas are confined to the uterus at diagnosis, which is consistent with the clinical findings in this case 1
Why the Other Options Are Incorrect
Leiomyosarcoma (Option a)
- Leiomyosarcoma would present as a rapidly growing intramural or submucosal mass, not as diffuse endometrial thickening 4
- Benign leiomyomas typically regress after menopause due to declining estrogen levels, so significant growth would be the red flag for sarcomatous change 4
- The cytology would show spindle cells rather than adenocarcinoma cells
Adenomyosis (Option b)
- Adenomyosis is a benign condition that would not produce malignant cells on cytology 5
- While it can cause uterine enlargement, it does not cause postmenopausal bleeding or malignant cytology
Squamous Metaplasia (Option c)
- Squamous metaplasia is a benign histologic finding that would not produce malignant cells 5
- This is an incidental microscopic finding, not a clinical diagnosis
Endometriosis Externa (Option d)
- External endometriosis would not cause endometrial thickening or malignant cells in vaginal discharge 5
- This condition involves ectopic endometrial tissue outside the uterus and would not explain the clinical presentation
Diagnostic Confirmation
The diagnostic sequence in this case follows established guidelines:
- Transvaginal ultrasound showing thickened endometrium (>4-5 mm) warrants endometrial sampling 1, 2
- Endometrial biopsy using Pipelle or Vabra devices has extremely high sensitivity (99.6% and 97.1% respectively) for detecting endometrial carcinoma 2
- Fractional curettage gives the diagnosis in 95% of cases 5
Critical Pitfall to Avoid
Never rely on ultrasound findings alone when malignant cells are present on cytology—tissue diagnosis through endometrial biopsy is mandatory to confirm the diagnosis, determine histologic type and grade, and guide surgical staging 5, 1, 2