Radiographically occult, diffuse intrasinusoidal hepatic metastases from primary breast carcinomas: a clinicopathologic study of 3 autopsy cases.

CONTEXT Liver metastases usually present as radiographically detectable mass lesions that do not significantly compromise liver function. Rarely, metastatic carcinoma can diffusely infiltrate hepatic sinusoids, a pattern of metastasis that may be missed on imaging studies, and can result in liver failure. OBJECTIVE To describe the clinicopathologic features of 3 cases of diffuse intrasinusoidal hepatic metastases from primary breast carcinomas identified at autopsy. DESIGN Clinical histories and radiographic, macroscopic, and microscopic appearances of the livers were compared. Sampled liver tissue was stained with antibodies to E-cadherin, smooth muscle actin, and CD44. RESULTS Two of 3 cases had a history of infiltrating ductal carcinoma of the breast and presented with new-onset liver failure, but no hepatic metastases were identified on radiologic imaging. An additional case had no history of carcinoma, presented with a severe thrombocytopenic thrombotic purpura-like syndrome, and metastatic carcinoma of the breast was diagnosed only at autopsy. The livers in all 3 cases at autopsy were homogeneous, firm, and tan-yellow, and contained no large metastatic lesions. Microscopically, poorly differentiated carcinoma diffusely infiltrated hepatic sinusoids. Antibodies to smooth muscle actin stained activated hepatic stellate cells lining involved sinusoids. Cell surface adhesion molecules, E-cadherin or CD44, were not detected in any hepatic metastases. CONCLUSION Diffuse intrasinusoidal hepatic metastases of breast carcinoma can occupy a large percentage of the hepatic volume, yet remain occult both radiographically and macroscopically. This type of metastatic spread can present as cryptogenic liver failure. The 3 cases we studied were associated with an absence of E-cadherin and CD44 expression.