Immunohistochemical diagnosis of Krukenberg tumors

The diagnosis of Krukenberg tumors, as in other types of metastatic tumors of unknown primary origin, can often be a challenge for clinicians. In many cases, traditional diagnostic methods are insufficient, requiring immunohistochemistry analysis for identifying the origin of metastatic tumors. In our study, we examined a total of 34 female patients with Krukenberg tumors with different sites of the primary tumor: gastric (n=18), colorectal (n=6) or breast (n=7) and tumors with unknown origin (n=3). Cytokeratin (CK) 7 and CK20, carcinoembryonic antigen (CEA) and cancer antigen (CA) 125 were applied. The analysis of immunohistochemical profiles for CEA and CA125 showed that, regardless of the histological origin, the predominant immunohistochemical profile was CEA(+)÷CA125(-). CK7÷CK20 profile was different depending on the histological origin of the Krukenberg tumors. Thus, for the cases of gastric origin, CK7(-)÷CK20(-) was present in 66.7% (12÷18) of the cases. For the cases with colorectal origin, the predominant immunohistochemical profile was CK7(-)÷CK20(+), in a percentage of 66.7% (4÷6). The combination CK7(+)÷CK20(-) was found in 85.7% (6÷7) among cases of breast origin. Consequently, the immunohistochemical profile CK7÷CK20 can have a key role in identifying the primary tumor in patients with Krukenberg tumors of unknown origin.