08 January 2025
: Case report
Radiological and Pathological Analysis of Pembrolizumab-Associated Lung Lesions: Diagnostic Challenges and Management
Unusual clinical course, Challenging differential diagnosis, Unusual or unexpected effect of treatment, Adverse events of drug therapy, Clinical situation which can not be reproduced for ethical reasons
Tomohito Okano1BDEF, Hajime Fujimoto1ABC, Toshiyuki Ito1BDE, Atsushi Tomaru1BDE, Haruko Saiki1BDE, Tatsuki Tsuruga1ABE, Taro Yasuma23BCD, Corina N. D'Alessandro-Gabazza23CDE, Esteban C. Gabazza

DOI: 10.12659/AJCR.945022
Am J Case Rep 2025; 26:e945022
Figure 4. Bronchoalveolar lavage fluid cells and histopathological findings. Giemsa staining of bronchoalveolar lavage fluid cells at 400× magnification revealed a significantly elevated cell count, with the differential count predominantly showing histiocytes and lymphocytes (A). Hematoxylin and eosin staining of lung tissue sections demonstrated a complex inflammatory process characterized by both chronic and acute inflammation. The histopathology revealed a dense infiltration of histiocytes, coupled with pronounced swelling of the alveolar epithelial cells. Scale bars indicate 50 µm (B, C).