There are numerous variable sized ill-defined low density lesions within the liver in keeping with metastatic disease. The portal vein is clear. Moderate intrahepatic bile duct dilatation and marked extra hepatic bile duct dilatation is secondary to a well-defined 13 mm round slightly hyperdense (to bile) filling defect obstructing the distal CBD. It has a central tiny focus of calcification and I cannot see any connection to the bile duct wall. There are numerous small calcified dependent gallstones within the distended gallbladder, none of which however are the size of the CBD filling defect. There is also a possible enhancing mural nodule arising from the gallbladder neck although this could represent a lymph node.
No definite colon primary malignancy is identified however there is there are 2 areas of mildly suspicious wall irregularity, within the hepatic flexure and the sigmoid colon. Simple cyst in the left kidney. No adrenal mass. Small volume of pelvic free fluid noted.
Lung bases are clear and emphysematous. No bony metastasis evident. Compression fractures of L3. L4 and L5 are likely long-standing.
Conclusion
Diffuse metastatic disease of the liver without an obvious primary identified. The bile ducts are obstructed at the level of the distal CBD by a likely 13 mm predominantly non-calcified calculus. It would be uncommon for this to represent a pedunculated bile duct tumour.
Potential sites for malignancy include a possible gallbladder enhancing nodule (gallbladder carcinoma) and minor colonic irregularity of the hepatic flexure and sigmoid colon (colorectal primary). Other common primaries such as lung and melanoma require exclusion. CXR is advised in the first instance.