Small round cell tumours

Small round cell tumours (SRCT), also small round blue cell tumours (SRBCT), are a group of tumours that have a similar histologic appearance.

It is a group of tumours that is seen more often in childhood than adulthood.

DDx:

• Neuroblastoma.
• Wilms tumour (AKA nephroblastoma).
• Alveolar rhabdomyosarcoma.
• Ewing sarcoma/PNET - this entity is dealt with in the bone tumours article.
• Lymphoma - large cell lymphomas, e.g. diffuse large B cell lymphoma, anaplastic large cell lymphoma.
• Retinoblastoma.
• Hepatoblastoma.
• Desmoplastic small round cell tumour (DSRCT).

Memory device: 4 -blastoma (hepato-, neuro-, nephro-, retino-), PNET/Ewing sarcoma (medulloblastoma), DSRCT, lymphoma, alveolar rhabdomyosarcoma.

Microscopic

Features:

• Sheets of cells, very cellular.
• Small cells ~ 2X RBC diameter.
• Scant cytoplasm.
• Coarse chromatin.
• +/-Nucleolus. (???)
• +/-Vascular.

See also

• Soft tissue lesions.