A child presents with unilateral proptosis which is compressible and increases on bending forwards. It is non-pulsalite and has no thrill or bruit. MRI shows retro - orbital mass with echogenic shadows. The most probable diagnosis is:

Ans. (a) Orbital varixRef: Yanoff and Ducker 2/e, p. 731 - 740, Kanski 6/e, p. 180 - 188Proptosis from orbital varix is unilateral (most cases nonpulsalite and has no thrill or bruit. It is compressible and is characteristically precipitated by increasing venous pressure as in assuming a depending position (bending forwards). MRI may show echogenic shadows from phleboliths (venous stasis leads to formation of phleboliths).* Proptosis with neurofibromatosis is not compressible and is not precipitated on increasing venous pressure and is pulsatile if associated with orbital roof fracture* Proptosis in Encephalocele is reducible but not compressible and Echogenic shadows are not a characteristic feature* Proptosis in carotico - cavernous fistula is pulsatile, associated with Bruit and Thrill and is not precipitated or aggrevated by increasing venous pressure