[Foreign body granuloma simulating malignant disease in the biliary tract].

Non-absorbable suture materials, such as silk, are able to form foreign body granulomas and stones and consequently their use should be avoided in surgical procedures in the biliary tract. We present the case of a patient who underwent surgery for a probable Klastkin tumor. During the intervention, a 1.5-cm tumor, with firm consistency, extrinsic to the biliary tract was found; the mass was extirpated with no compromise to the biliary tract. Macroscopic examination revealed suture (silk) material. The histopathological report described an inflammatory tumor, composed essentially of macrophages and foreign body giant cells, and identified a suture within the cell cytoplasm. The interest of this case lies in the rarity of this entity, the difficulty of preoperative diagnosis, and its possible confusion with other anatomic and clinical syndromes.