Taverna et al. BMC Cancer 2010, 10:62 http://www.biomedcentral.com/1471-2407/10/62 Page 3 of 4 Figure 4 Tumoural cells were found immunopositive for cytokeratin 7 (A), CDX2 (B), and b-catenin (C). Objective magnification: 20×. Figure 5 The definitive pathological examination revealed a mucinous cystoadenocarcinoma of the appendix invading the caecal wall with metastasis of the anterior wall of the bladder (A). Adjacent to the tumour in the intestinal mucosa foci of high grade dysplasia/ adenocarcinoma in situ were also identified thus confirming the appendiceal origin of the primary tumour (B). Objective magnification: 20×. found of metastatic origin and not locally invading from the primary appendiceal tumoural site. The primary lesion of the appendix was nearby the posterior bladder wall without local invasion. Thus confirming that the anterior bladder lesion was a secondary localization of appendiceal carcinoma. Ultrasonography and abdomen enhanced CT scan unrevealed any gastrointestinal pri- mary lesion. We therefore decided for a partial cystect- omy, because metastases were found in the anterior portion of the bladder, completely unconnected from the primary appendiceal tumour. We have considered the possibility of a synchronous cancer, but the overlap between the morphologic features of the tumour and the clinical characteristics of the disease strongly support the metastatic nature of the bladder adenocarcinoma. In addition, we found multiple metastasis at the level of colic lymph-nodes and not at the level of bladder lymph- nodes. This supports the fact that the bladder lesion is of metastatic origin and not definable as a primary tumoural lesion. Some explanations of the involved metastatic pathways might linked to the fact that tumoural clones may have embolized lymphatic vessels located under the peritoneal serous membrane of the appendiceal-caecum region, and after the colonization of a high number of loco-regional lymph-nodes, tumoural cells might have reach the peri-bladder lymph-nodes. However, this hypothesis is in contrast with the fact that no new blad- der lesions have been found during the follow-up of the patient. In our presented case the anatomical characteris- tics of non contiguity between the anterior bladder wall and the appendix, caecum and peritoneum, and the dif- ferent neoplastic lymph-node development between blad- der and colic cancer led us to hypothesize that the metastatic pathway was haematogenous. The rarity of the appendiceal carcinoma invading the urinary bladder and its usual involvement of nearest organs and the posterior bladder wall, led us to first describe this case which demonstrates the ability of the appendiceal carcinoma to metastasise different portions of urinary bladder. Consent Written informed consent was obtained from the patient for publication of this case report and any accompany- ing images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.