The radiograph demonstrates an accessory navicular. There is no periosteal changes, bony destruction, or matrix present on the radiograph eliminating selections 3 and 4 for the work-up of malignancy. Conservative measures are the first line treatment for the symptomatic accessory navicular. Surgical excision is a reliable intervention for cases refractory to conservative management. Grogan et al reviewed 39 patients with symptomatic accessory naviculars. Twenty-five went on to surgical resection following failure of conservative management with all 25 achieving complete relief.
Kasser JR: The foot, in Morrissy RT, Weinstein SL (eds): Lovell and Winter’s Pediatric Orthopaedics, ed 6. Philadelphia, PA, Lippincott Williams and Wilkins, 2006, pp1257-1328
Grogan DP, Gasser SI, Ogden JA: The painful accessory navicular: A clinical and histopathological study. Foot Ankle 1989; 10:164-169
PMID:2613130 (Link to Abstract)