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 5 Radiographic imaging. Horizontal computed tomography section showing (A) development of sternal metastasis (left) and multiple lung metastases (middle and right) upon recurrence. (B) One month after receiving pembrolizumab, gemcitabine, and carboplatin, sternal mass (left) and bilateral lung metastases (middle and right) indicating pseudo-progression. (C) Thirty months after chemoimmunotherapy initiation, the metastatic lesions shrank significantly. Lesions are indicated by red arrows.