Case: We report a rare case of dysplasia epiphysealis hemimelica in an 11-year-old male child involving the patella. The patient noticed swelling in the right knee 6 months before presentation. On evaluation, there was a mass lesion originating from superior pole of the patella extending into the suprapatellar pouch. On opening the knee joint, it was found to be mainly cartilaginous in nature. Surgical excision of the mass was carried out.
Conclusion: Trevor disease should be considered in the differential diagnosis of a mass originating from the patella in children. The recommended treatment is complete excision of the mass.