Fig. 1

Metastatic Cholangiocarcinoma. a Liver with grossly visible tan mass measuring 23 × 20 × 17 cm primarily involving the right lobe and multiple satellite lesions. b Cross-section of the liver demonstrating the mass and multiple satellite lesions. c A satellite lesion within the liver shows nests of cancerous cells with round to oval nuclei within a fibrotic stroma (right) invading into adjacent normal hepatocyte trabeculae and sinusoids (left). d Epicardial and myocardial invasion of metastatic cholangiocarcinoma. Representative section shows nests of tumor cells within a fibrotic stroma around a large vessel (bottom) invading into cardiac myocytes (top). e Lung with multiple tan-pink metastatic deposits on the visceral pleura. f Bone marrow involvement by metastatic cholangiocarcinoma. Normal trilineage hematopoiesis involving erythroid precursors, myeloid precursors, and megakaryocytes to the right of the bone spicule is replaced by solid/trabecular areas of tumor cells to the left of the bone spicule