A rare case report of Patellar Osteochondroma

Osteochondroma (OC) is the most common benign tumor of the skeleton. However, patellar OC is very rare. Only five case reports have been published yet and only 1 after the year 1972. OCs grow during childhood through adolescence, but usually growing ends when the epiphyseal plates close. In an adult, the growth of an OC suggests the diagnosis of malignant transformation to a chondrosarcoma. However, enlargement of a patellar OC reported as benign after skeletal maturity is present in literature.

We report the clinical and radiologic findings of a patellar OC in a 50-year-old female, with a 3-year progression of swelling, not painful, well-defined margins, normal skin, and no neurovascular deficits or functional impairment. The tumor was surgically resected, and histopathological examination did not show malignancy. After 2 years of follow-up, the patient has no complaints and no signs of recurrence.

Patellar OCsare extremely rare with only a few reports published. It should be kept in mind that benign OCs can show symptomatic growth in skeletally mature patients without malignant transformation.