Embryonal rhabdomyosarcoma of orbit--a case report.

Embryonal rhabdomyosarcoma of orbit presenting as a case of rapid proptosis of the right eye is reported in a 4 year old male child. There was no evidence of recurrence during a follow up of 6 months. Rhabdomyosarcoma is one of the most common primary malignant orbital neoplasms of child hood. It usually produces a precipitously progressing unilateral proptosis of sudden onset. It is a highly malignant neoplasm of pleuripotential embryonic mesoderm, which commonly differentiates to form cells similar to rhabdomyoblasts of the foetus. Because of the presence of elongated cells that contain abundance of eosinophilic glycogen rich cytoplasm, it is generally referred to as embryonal form of rhabdomyosarcoma.