A Case Report of Heel Pain Mimicking Plantar Fasciitis and Osteosarcoma: A Unique Presentation of a Nora's Lesion.

Bizarre parosteal osteochondromatous proliferation, otherwise known as "Nora's lesion," is a rare benign neoplasm first described by Nora in 1983. The exact etiology of this neoplasm remains unknown, and its presentation in the lower extremity presents a diagnostic challenge, as both clinical and radiologic features cannot fully differentiate it from other neoplasms. We present the case of a 48-year-old female with plantar heel pain secondary to Nora's lesion mimicking plantar fasciitis and periosteal osteosarcoma. Following bone biopsy for histopathologic analysis, the patient's symptoms spontaneously resolved, and she returned to activity with complete resolution of symptoms 18 months post biopsy. Bizarre parosteal osteochondromatous proliferation as an etiology for plantar heel pain has not been previously described in the literature. Although rare, it should be considered in the differential diagnosis for patients presenting with plantar heel pain, especially after failed conservative treatment. Following diagnostic confirmation by histopathology, complete surgical excision is the treatment of choice.