Fibrous Hamartoma of Infancy at Suprapatellar Region: A Case Report and Review of the Literature

Fibrous hamartoma of infancy (FHI) is a rare benign soft tissue tumor, but it is possible to present as a rapid-growing mass mimicking a malignancy with interference of patient's ambulation or joint range of motion. Here we report what is, to our knowledge, the first case occurring at suprapatellar region with initial presentation as a deep tender nodule with ill-defined margin and rapid enlargement. The rarity of this reported case is about the late-onset, fast disease progression, the morphology of the mass on magnetic resonance imaging (MRI), and the severe interference of patient's daily activities.