Clinical Presentation of Endometrial Stromal Neoplasms
Patients with endometrial stromal neoplasms most commonly present with abnormal uterine bleeding, an enlarged uterus or pelvic mass, and abdominal pain, though some cases are discovered incidentally. 1, 2, 3
Typical Clinical Presentation
Primary Symptoms
- Abnormal uterine bleeding is the most frequent presenting symptom, occurring in the majority of patients 2, 4
- Palpable enlarged uterus or pelvic mass detected on physical examination 2, 5
- Abdominal or pelvic pain 2, 5
- Gastrointestinal symptoms may occur, particularly when extrauterine involvement is present 5
Patient Demographics
- Age range: Predominantly affects peri- or postmenopausal women, typically between 32-52 years (mean age 39-50 years) 2, 3, 5
- Annual incidence: Approximately 0.30 per 100,000 women 3
- Low-grade endometrial stromal sarcoma (LG-ESS) presents as stage I-II disease in two-thirds of patients at diagnosis 3
Incidental Findings
- Some cases are discovered incidentally during postpartum examination or routine imaging 2
Ultrasound (USG) Findings
Transvaginal Ultrasound Characteristics
Primary Imaging Features:
- Soft, polypoid intracavitary masses are the most common appearance (seen in approximately 60% of cases) 2
- Predominantly intramyometrial masses with infiltrative characteristics (approximately 40% of cases) 2
- Tumor size: Ranges from 1.2 to 24.5 cm in greatest dimension 2, 5
Specific Ultrasound Patterns
Mass Characteristics:
- Single nodule, multiple masses, or poorly demarcated lesions with occasional cystic degeneration 6
- Multilocular cystic appearance in rare cystic variants, which can be detected by ultrasonography 6
- Gelatinous appearance in some cases 2
Vascular Features:
- Numerous small thin-walled vessels are characteristic on Doppler evaluation 2
- Color and spectral Doppler can identify abnormal vascular patterns within the tumor 7
Important Imaging Considerations
Limitations of Ultrasound:
- Transvaginal ultrasound cannot reliably distinguish between benign and malignant endometrial lesions with certainty 1
- The differential diagnosis of multicystic endometrial stromal sarcoma versus other cystic uterine tumors can be very difficult on ultrasound alone 6
Recommended Imaging Approach:
- Combined transabdominal and transvaginal ultrasound provides the most comprehensive assessment 1, 8
- Sonohysterography (saline infusion sonography) can help distinguish between focal and diffuse pathology when initial ultrasound is inconclusive 1, 7
- MRI with diffusion-weighted imaging should be considered when ultrasound findings are equivocal or further characterization is needed, as it has sensitivity up to 79% and specificity up to 89% for malignant uterine pathology 1
Critical Diagnostic Pitfalls
Common Misdiagnoses
Endometrial stromal neoplasms are frequently misdiagnosed initially (in 25% of cases), with the following differential diagnoses commonly considered 5:
- Sex cord-stromal tumors
- Gastrointestinal stromal tumor (GIST)
- Leiomyosarcoma
- Müllerian adenosarcoma
- Adenomyosis or endometriosis 4
Key Distinguishing Features
- Association with endometriosis is common (seen in approximately 48% of cases) 5
- Multiple site involvement occurs in approximately 63% of cases with extrauterine disease 5
- Myometrial infiltration with characteristic small arterioles is a hallmark feature 2
Mandatory Next Steps After Imaging
- Endometrial tissue sampling is mandatory when endometrial stromal neoplasm is suspected, as imaging alone cannot definitively diagnose malignancy 1, 8
- Hysteroscopy with directed biopsy is preferred over blind endometrial sampling for focal lesions 8
- Avoid morcellation during surgical removal, as this is contraindicated in suspected stromal sarcomas 3