16 May 2026
: Case report 
Long-Term Response to Pembrolizumab in Metastatic Metaplastic Breast Carcinoma: A Case Report
Unusual clinical course, Unusual or unexpected effect of treatment
Yuki Oshima ABCDEF 1, Takamasa Suzuki D 1, Yumi Fukaya D 1, Keiko Hosoya D 1, Yuko Tanaka D 1, Makoto Wakahara ABCDEF 1*, Yoshihisa Umekita CD 2, Yugo Tanaka ABCDEF 1DOI: 10.12659/AJCR.952330
Am J Case Rep 2026; 27:e952330
Figure 2 Pathological findings from the surgical specimen. The metaplastic component consisted mostly of spindle cell carcinoma (A) (hematoxylin and eosin staining, ×200). Carcinoma cells were positive for AE1/AE3 (B), CK5/6 (C), and p63 (D) (×100).