Figure 2.

EGFR and HER2 overexpression and gene amplification in a spindle cell carcinoma. (a) Photomicrograph of a spindle cell carcinoma (haematoxylin and eosin). Immunohistochemical analysis revealed (b) EGFR grade 3+ positivity and (c) HER2 grade 2+ reactivity. (d) CISH demonstrating EGFR amplification (clusters of signals in the nuclei of neoplastic cells). Note the presence of one or two copies of EGFR in stromal cells (arrowheads). (e) CISH for HER2 gene: no amplification (2–3 gene copies/nucleus). CISH, chromogenic in situ hybridization; EGFR, epidermal growth factor receptor; HER, human epidermal growth factor receptor; MBC, metaplastic breast carcinoma.