Metastatic Colon Cancer

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Image Description

Metastatic colo-rectal cancer: Like other adenocarcinomas of the gastrointestinal tract (gastric, pancreas), colo-rectal adenocarcinomas have a tendency to metastasize to the liver. Liver is often the only site of metastatic spread in many cases.

FNA smears often show dirty, necrotic background. Some cases are predominantly mucinous and show clusters of malignant cells floating in viscous mucin on FNA smears.

Needle core biopsy specimens show moderate-to-poorly differentiated glands with abundant central necrosis. Mucinous carcinomas show malignant glands clinging to stroma and accompanied by pools of mucin.This photograph shows metastatic colon adenocarcinoma in liver in an elderly female.

Treatment: Patients with isolated liver metastases from colo-rectal cancers derive long-term disease-free survival (5-yr survival rate in 50%) or even cure (20% of cases) from metastasectomy. The goal is complete tumor extirpation with negative margins. Patient who are unable to tolerate or refuse surgery may be offered radiofrequency ablation of tumor.

About the Disease

Metastasis is the most common malignancy in non-cirrhotic livers in the Western countries. About 40%-50% of patients dying from cancer have liver metastases. Liver is highly susceptible due to dual blood supply (hepatic and portal) and fenestrations in sinusoidal epithelium which allow tumor cells to escape into the parenchyma. Primary sites in adults: pancreas, stomach, colon, lung, breast, kidney, malignant melanomas, and soft tissue sarcomas. Malignancies of gall bladder, extrahepatic bile ducts, stomach, and pancreas can spread to liver by direct extension. Primary sites in children: neuroblastoma, Wilms tumor, and rhabdomyosarcoma. Presentation ranges from no symptoms to fulminant hepatic failure. Patients may develop malaise, anorexia, weight loss, abdominal pain, and obstructive jaundice. Diagnosis can be accurately made in most cases by CT- or ultrasound guided-FNA and needle core biopsies. Metastases form multiple, discrete expansive masses or ill-defined infiltrative areas. Larger nodules undergo necrosis and fibrosis producing umbilication. Liver may be greatly enlarged with an irregular surface. Malignancies of breast, stomach, lung, pancreas, and lymphomas may produce miliary involvement. Metastases are quite rare in cirrhotic livers. Microscopic features are those of the primary tumor. Metastatic adenocarcinomas may invade bile ducts and show intrabiliary growth mimicking cholangiocarcinoma. Prognosis is poor in most cases (with some exceptions). Most patients die within 1 year of presentation. Resection of isolated liver metastases from colo-rectal cancers can produce long-term disease-free survival or even cure in some cases. Patients with liver metastases from neuroendocrine tumors and Carcinoid syndrome get dramatic relief from symptoms after resection of metastatic foci. References: 1. Iacobuzio-Donahue, C. A. & Montgomery E. (2012). Gastrointestinal and Liver Pathology - 2nd Edition. Philadelphia, PA. Elsevier Saunders. 2. Feldman, M., Friedman, L. S., & Brandt, L. J. (2016). Sleisenger & Fordtran's Gastrointestinal & Liver Disease - 10th Edition. Philadelphia, PA. Elsevier Saunders. 3. Goldblum, J. R. et al (2018). Rosai and Ackerman's Surgical Pathology - 11th Edition. Philadelphia, PA. Elsevier.4. DeVita, V. T., Lawrence, T. S., & Rosenberg, S. A. (2019). Cancer - Principles & Practice of Oncology - 11th Edition. Wolters Kluwer.

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