Pathological fracture of the fifth metatarsal bone from an extraosseous ganglion cyst

抄録

Objective: Ganglion cysts are benign soft-tissue tumors that are relatively rare in the foot. Although most foot ganglia are asymptomatic, cases of structural compromise and pathological fractures are rare.

Patient: A 65-year-old woman presented with right lateral foot pain without direct trauma. Physical examination revealed a soft, non-erythematous mass between the fourth and fifth metatarsals. Imaging demonstrated a scalloping depression at the fourth metatarsal and a pathological fracture of the fifth metatarsal shaft.

Results: A surgical excision was performed by tracing the cyst to the fourth metatarsophalangeal joint. The fifth metatarsal was stabilized using a four-hole plate. Bony union was achieved at six weeks with pain resolution.

Conclusion: This case highlights the importance of considering the mechanical compression exerted by the cyst and possible osteoporosis as contributing factors. Complete excision with stalk removal combined with fixation is recommended to prevent recurrence and to optimize functional outcomes.