Rhabdomyomatous mesenchymal hamartoma (RMH) is a subcutaneous lesion that is characterised by a normal epidermis overlying a dermis that contains randomly arranged mature striated muscle fibers associated with varying amounts of mesenchymal elements such as adipose tissue, collagen and blood vessels. Herein we report a mesenchymal hamartoma with rhabdomyomatous features occurring in the orbit.

Case report

A 2-year-old boy was referred to the clinic with a history of right unilateral axial proptosis presenting on the fourth day of life with no useful vision ipsilaterally. Two orbital biopsies had been performed, the first being unsuccessful, and the second showing haphazardly arranged skeletal muscle fibers and fibrous tissue. On examination, he had no light perception OD, ptosis, fixed extraocular movements, and a pale atrophic optic disc. Ultrasound features included a solid, well-outlined highly reflective mass that was indenting the globe. Magnetic resonance imaging with gadolinium of the brain and orbit, at 5 months, revealed a …