The need for larger studies in an uncommon disease implies that multi-institutional studies need to be performed, and the GI Oncology community needs to recognize and embrace this fact. Finally, it is worth noting that, while the technology used by Ustwani and colleagues has received regulatory approval for clinical use in patients with breast, prostate, and colon cancer, and is the only reproducibly validated assay methodology, a variety of new technologies are being developed to investigate

circulating tumor cells. Some of these new methods are similar to the Cell Search assay in that Inhibitors,research,lifescience,medical they rely on the expression of epithelial antigens (12), but others are based on physical, or other characteristics of tumor cells (13). Investigators must be aware of these newer technologies, and it is quite possible that the optimal GSI-IX method for CTC determination will vary with tumor type Inhibitors,research,lifescience,medical and situation. So what can we make of the role of CTCs in biliary cancer? At present,

little, other than the important observation that they can be detected in this group of diseases. Inhibitors,research,lifescience,medical But if the proverbial journey of a one thousand miles begins with a single step, that step has been taken, and that step has implied a path that needs to be followed. Footnotes No potential conflict of interest.
The patient is a 44-year-old female who presented at the age of 42 years in April 2008 with right lower quadrant pain, gradually increasing over

a few months prior to evaluation. Work up included a CT scan of the abdomen and pelvis, which revealed a 6.4 cm × 7.0 cm heterogeneous mass in the right Inhibitors,research,lifescience,medical lower quadrant (RLQ) interposed between the right lateral abdominal wall and the wall of the ascending colon (Figure 1A). The colon itself and the liver appeared unremarkable, and minimal free fluid in the cul-de-sac was noted. A CT guided biopsy of the mass showed a moderately differentiated adenocarcinoma of unknown origin. She underwent an extensive gynecologic work up, colonoscopy and upper endoscopy, all of which were negative. Inhibitors,research,lifescience,medical The patient was taken for an exploratory laparotomy in June 2008 that showed a 7 cm well-encapsulated heterogenous tumor in the right paracolic gutter invading into the retroperitoneum and involving the abdominal wall. The liver and the gallbladder appeared normal with the exception of a 1.5 cm × 1.0 cm calcified lymph node seen on the undersurface of the liver, at the base of the gallbladder. aminophylline This was removed and pathology showed non-small cell carcinoma with hepatoid features. Intraoperative gynecologic and urologic consults were done, which ruled out involvement of these organ systems. Figure 1 A: CT scan of the abdomen showing the RLQ mass; B: The RLQ mass is PET-avid; C: Lateral view of the PET-avid RLQ mass; D: Hepatoid pattern; E: Diffuse 3+ AFP; F: Diffuse 3+ CAM; G: Patchy 3+ HepPar; H: Canalicular CEA staining.