Acute myelomonocytic leukemia during pembrolizumab treatment for non-small cell lung cancer: A case report

Figure 1 Contrast-enhanced neck computed tomography, contrast-enhanced chest computed tomography, and ¹⁸F-fluorodeoxyglucose positron emission/computed tomography. A: 41 mm × 64 mm sized bulky necrotizing lymphadenopathy in left cervical level V; B: Multiple various sized necrotizing lymphadenopathy on both cervical level II to V; C: Contrast-enhanced chest computed tomography shows 2 cm sized heterogeneous enhanced nodule in anterior segment of left upper lobe (LUL); D: Large periosseous mass formation involving lateral arc of left 7^th rib; E: ¹⁸F-fluorodeoxyglucose positron emission/computed tomography showed a hypermetabolic nodule in LUL; F: Multiple enlarged hypermetabolic mass on both cervical level II to IV, and hypermetabolic mass on left 7^th rib.

Figure 2 Microscopic examination of the specimen using hematoxylin and eosin staining and immunohistochemistry staining. A and B: Microscopic examination of the specimen using hematoxylin and eosin staining show keratinized malignant cells (magnification: A, × 100; B, × 400); C: Immunohistochemically, neoplastic cells are positive for p63 (C, × 100); D: The Programmed death-ligand 1 tumor proportion score was ≥ 50% (× 400; PD-L1 IHC 22C3 pharmDx™ Kit, DAKO, Denmark).

Figure 3 After 3 cycles of pembrolizumab, contrast-enhanced neck and chest computed tomography and evaluation after 4^th chemotherapy. A, C, E: Evaluation after 4^th chemotherapy; B, D, and F: After 3 cycles of pembrolizumab, contrast-enhanced neck and chest computed tomography shows the markedly decreased size of metastatic lymphadenopathy on both cervical level II to V, enhanced nodule in anterior segment of left upper lobe, and mass in left 7^th rib compared with response evaluation after 4^th chemotherapy.

Figure 4 The blood smear and bone marrow biopsy. A: The blood smear shows 15% blast cells and hypogranulation with basophilia with monocytosis; B: On the bone marrow biopsy, myeloblast was increased in number and counted 40.92% of nucleated cells.