Dramatic Clinical Response of Relapsed Metastatic Extramammary Paget’s Disease to Trastuzumab Monotherapy

Figure 1

Histologic and immunohistochemical findings of the recurrent tumor.

(a) Histologic section of the recurrent tumor showing characteristic large, round cells with large nuclei and light cytoplasm. (hematoxylin-eosin, original magnification ×400)

(b) Immunohistochemical staining for HER2 (human epidermal growth factor receptor protein 2, original magnification ×400) demonstrating uniform, strongly positive (3+) staining