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Non-Rhabdomyosarcoma (Non-RMS)



Alveolar Soft Part Sarcoma



Alveolar soft part sarcoma is a rare tumor and accounts for less than 1% of all adult soft tissue sarcomas and 1- 2% of non-RMS in children.

This tumor has a characteristic translocation: t(X;17)(p11;q25)

Generally involves the muscles and soft tissues of the lower extremities (buttocks, thighs and legs).

Metastatic disease is often present at diagnosis - frequently with multiple small pulmonary metastases.  Bone and brain metastases may also occur.



  • Multinodular, well circumscribed tumors
  • Microscopically tumors have an alveolar structure.  Center of alveolar space being formed by detachment of necrotic cells with surrounding capillaries
  • Cells are large with abundant cytoplasm.  Mitosis are rare.
  • Pathognomic feature: Secretory process with the formation of cytoplasmic membrane-bound crystals (PAS positive, diastase resistant) often seen with electron microscopy.  These granules contain monocarboxylate transporter 1.


Indolent disease with 7 year survival of 80% - but difficult to cure because of the high incidence of metastases.





Cure Alveolar Soft Part Sarcoma International








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