Adenosquamous carcinoma of the liver: clinicopathologic characteristics and cytokeratin profile

The clinicopathologic characteristics, biologic behavior, and histogenesis of primary adenosquamous carcinoma (ASC) of the liver have yet to be fully clarified.

Eight cases of ASC of the liver were analyzed both clinicopathologically and immunohistochemically using antibodies of cytokeratin (CK) 7, CK 8, CK 18, CK 19, and CK 903 (CK 5, CK 10, CK 11, and CK 14). The survival curve of the 6 patients with surgically resected ASC was compared with that of the 32 patients with common cholangiocarcinoma (CC).

Most ASCs had invasive pathologic features, including venous invasion, lymphatic permeation, and intrahepatic metastases. There were lymph node metastases from 7 tumors (88%), and most of the metastases were adenocarcinoma. All adenocarcinoma (AC) components were positive for both CK 7 and CK 19. The squamous cell carcinoma (SCC) components were positive for CK 7 in all cases but were positive for CK 19 in only 5 cases (62.5%). The ACs were positive for CK 903 in only 3 cases (37.5%), whereas all SCCs were positive for CK 903. Almost all ACs were positive for both CK 8 and CK 18, whereas the SCCs were positive for CK 8 in only 3 cases (37.5%) and for CK 18 in no cases. All 6 patients with surgically resected ASC died of the disease within 1 year postoperatively. Their survival curve was significantly worse than that of the 32 patients with common CC (P < 0.001). The two patients on whom autopsy was performed also died within 1 year after diagnosis.

ASC tended to have more aggressive biologic behavior and a poorer prognosis than common CC. The authors' immunohistochemical analysis of CK expression indicated that most of the ASCs of the liver that were studied developed from a squamous transformation of the preexisting CC.