RESUMEN
Foreign body granuloma can occur after any surgical procedure, where non absorbable sutures have been used. It may occur due to forgotten other non-absorbable like gauze. Though foreign body granuloma has been reported involving many organs, but it is very rare to involve urinary bladder wall and to present it as urinary bladder tumor. We present such a unique case where use of Barbour thread for tubal ligation led to a large foreign body granuloma infiltrating bladder wall and presenting as bladder mass. Even contrast enhanced computed tomography showed a mass, which appeared to arise from the anterior aspect of the bladder suggestive of urachal carcinoma. Only on histopathological examination diagnosis was confirmed to be foreign body granuloma.