HER2 changes to positive after neoadjuvant chemotherapy in breast cancer: A case report and literature review

Figure 1 Malignant tumor in the right breast when initially diagnosed. A: Ultrasound showing the mass measuring 2.73 cm × 2.13 cm × 2.57 cm in the 10-o'clock position of the right breast; B: Ultrasound showing the largest right axillary lymph node measuring 1.2 cm × 0.9 cm; C: Hematoxylin-eosin staining indicates an invasive ductal carcinoma (×100); D: Positive control of fluorescence in situ hybridization (FISH); E: Negative control of FISH; F: FISH result of the biopsy specimen.

Figure 2 Ultrasound result after neoadjuvant chemotherapy and histopathological and fluorescence in situ hybridization findings of the resected tumor. A: Ultrasound demonstrating the tumor measuring 0.8 cm × 0.7 cm after neoadjuvant chemotherapy (arrow); B: Histopathological finding showing the tumor cells tubular arrangement and the development of invasion (H&E staining, × 50) (arrow); C: Positive control of fluorescence in situ hybridization (FISH); D: Negative control of FISH; E: FISH result of the surgically resected tumor.