List the three pathological subtypes of pleomorphic rhabdomyosarcoma.
1. Classic type 2. Round cell. 3. Spindle cell
What is the most common location of pleomorphic rhabdomyosarcoma?
The lesion mostly occurs in the limbs and especially the thigh.
List possible differential diagnoses of soft tissue tumours of the limbs in adults?
1. Peripheral nerve sheath tumours (benign and malignant) 2. Other sarcomas include undifferentiated pleomorphic sarcoma and synovial sarcoma. 3. Aggressive fibromatosis and other benign fibrous tumours. 4. Soft tissue metastases
1. H & E.
2. Excellent nuclear staining Myo D1 – indicating rhabdomyoblasts.
3. H & E routine section showing the tumour with severe nuclear pleomorphism and mitotic activity. Highly cellular.
4 and 5. Excellent cytoplasmic staining for muscle actin indicating muscle derivation.
Diagnosis: High-grade pleomorphic rhabdomyosarcoma.
Histology report and images courtesy of Dr Jefferey A. Posen.