Cytologic diagnosis of signet-ring cell carcinoma of the breast.

OBJECTIVE

To examine the cytologic features of signet-ring cell carcinoma (SRCC), defined as carcinoma dominated by signet-ring cells, of the breast and to discuss problems that occur in cytodiagnosis.

STUDY DESIGN

Five cases of SRCC of the breast were examined cytopathologically. Signet-ring cells were subclassified into intracytoplasmic lumina (ICL) type and non-ICL type. ICL type had large ICL containing mucin. Non-ICL-type cells had wide, amorphous cytoplasm diffusely dispersed with mucin.

RESULTS

In cases 1 and 2, fine needle aspiration biopsy (FNAB) revealed many signet-ring cells (non-ICL type), suggesting SRCC. Histologic diagnoses were ductal SRCC containing many signet-ring cells (non-ICL type). In cases 3 and 4, signet-ring cells (ICL type) were found sporadically among carcinoma cells without signet-ring features. Signet-ring cells were not regarded as the major component of the cells; thus, the cytologic diagnoses were lobular carcinoma, not otherwise specified. Pathologic diagnoses were lobular SRCC. Signet-ring cells were mostly ICL type. In case 5, most carcinoma cells on the smears showed signet-ring features (non-ICL type), suggesting SRCC. The histologic diagnosis was lobular SRCC, and signet-ring cells were mostly non-ICL type.

CONCLUSION

Ductal SRCC yielded more cellular smears as compared with lobular SRCC; therefore, cytologic diagnosis was easier in the former.