ERBB2 and metastatic neoplasm: Table 1 summarizes the histological data. The HER2 expression was negative in all tumors (PILCs and ILCs). In the PILC group, lymph nodes were involved with metastatic carcinoma in 37% cases (negative in 47% and unknown in 16%) whereas in the ILC group, 70% had metastatic tumor to lymph nodes (negative in 30%). The 21-gene recurrence score assay (Oncotype Dx) was performed on 10 PILCs and 6 ILCs. The 21-gene recurrence score assay has been clinically validated and is used to classify tumors into low (<18), intermediate (18-30), and high (≥31) risk groups [15].