Diagnosis of extension and treatment of carcinoma of the gallbladder

: Diagnosis of extension by intraoperative ultrasonography (IOUS) and treatment based on the degree of histological extension in carcinoma of the gallbladder are discussed. IOUS is a useful technique for the diagnosis of the depth of wall invasion and direct invasion of the liver. The authors diagnose the depth of wall invasion based on the layer structure, unequal width, and discontinuity of the layer echogram. By this technique, mucosal cancer (m cancer) or cancer extending to the proper muscle layer (mp cancer) can be differentiated from cancer with submucosal invasion (ss cancer), and also ss cancer from cancer exposing the serosa (se) or cancer infiltrating to the serosa (si). However, differentiation between m cancer and mp cancer is not possible by IOUS or by other diagnostic techniques. In terms of histological extension, lymph node metastasis or vascular and nerve invasion is not found in m cancer, but in some cases of mp cancer vascular invasion is present. As a radical operative procedure for early m and mp cancer, full-thickness cholecystectomy or partial resection of the liver bed and dissection of lymph nodes 8, 12, and 13 should be conducted. As lymph node metastasis and vascular and nerve invasion are frequent in ss or more advanced cancer, complete lymph node dissection should be performed. Cholecystectomy, partial resection of the liver bed, bile duct resection, and dissection of lymph nodes 8, 12, and 13 is the preferred radical operative procedure for ss cancer. In the cases with in metastasis to lymph nodes 8 and 13, pancreatoduodenectomy is combined. The basic operative procedure for se and si cancer has not been established, but is should be radical and safe. Considering the poor prognosis and frequency of lethal postoperative complications, at present we should not only expand the resected area but select a reasonable and well-balanced operative procedure depending on the degree of cancer extension.