Leiomyosarcoma
Synonyms: LMS, Smooth muscle sarcoma
Second most common STS
Quick Facts
Behaviour
Malignant
Category
Soft tissue
Grade
Variable
Synonyms
- LMS
- Smooth muscle sarcoma
Category
Soft tissue
Behaviour
Malignant
Grade
Variable
Gender
M = F
Tissue of Origin
Smooth muscle
Epidemiology
- Second most common STS in adults
- Peak incidence 50-70 years
- Can arise in any location with smooth muscle
- Often deep-seated and large at diagnosis
Clinical Features
- Painless or mildly painful mass
- Rapid growth in some cases
- May present with complications (GI bleeding if visceral)
Location
- Retroperitoneum
- Deep thigh
- GI tract
- Biliary tract
- Subcutaneous tissues (rare)
Imaging
- MRI shows heterogeneous T2 signal
- Varying enhancement post-contrast
- May show necrosis or hemorrhage
- Difficult to distinguish from Benign leiomyoma
Pathology
- Fascicular arrangement of smooth muscle cells
- Increased mitotic activity
- Spindle cell morphology
- Cytologic atypia
Genetics
- No specific recurrent cytogenetic abnormality
- Complex karyotypes common
Treatment
- Wide surgical excision primary treatment
- Adjuvant chemotherapy for High-grade/large tumours
- Radiotherapy for unresectable or recurrent disease
Prognosis
- Grade and size most important prognostic factors
- 5-year survival 50% for High-grade
- Retroperitoneal location associated with worse prognosis
Key Points
- Second most common STS
- Often presents at advanced stage
- Grade and depth crucial for treatment planning
- Regular imaging Follow-up essential
Workup - Local Imaging
MRI with contrast
Workup - Biopsy
- Core needle biopsy recommended
- Assess grade and mitotic activity
Workup - Staging
CT CAP
Follow-up Summary
- 1
Years 1–2
3–4 monthly clinical review + CXR; MRI primary site at 3 months post-op then 6-monthly
- 2
CT chest every 3–4 months for first 2 years (pulmonary metastasis is primary concern)
- 3
Years 3–5
6-monthly clinical review + CXR; CT chest 6-monthly
- 4
Years 6–10
Annual clinical review + CXR; CT chest annually
- 5
Discharge at 10 years with documented self-monitoring advice
- 6
Radiotherapy patients
monitor irradiated field for late effects at each review
Medical disclaimer
The content on Sarcopedia is for educational and informational purposes only and does not constitute medical advice. It is not intended to be a substitute for professional medical diagnosis or treatment. Always consult with a qualified physician regarding any health concerns or before starting any new treatment. Reliance on any information provided on this site is solely at your own risk.