case_images: PMC10941986_01
case_images: Histopathological findings for patients 1 and 2. (A) Patient 1. Non-neoplastic proliferation showing lymphocyte emperipolesis on 800x increase; (B) Patient 1. Positive immunohistochemistry for CD68 (indicating macrophages) on histiocytic infiltrate; (C) Patient 1. Immunohistochemistry with occasional positivity for S100 on histiocytic infiltrate; (D) Patient 2. Non-neoplastic proliferation showing lymphocyte emperipolesis on 400x increase; (E) Patient 2. Non-neoplastic proliferation showing lymphocyte emperipolesis on 800x increase; (F) Patient 2. Positive immunohistochemistry for CD68 (indicating macrophages) on histiocytic infiltrate; (G) Patient 2. Positive immunohistochemistry for S100; Black arrows indicate emperipolesis on (A, D and E), and indicate immunohistochemistry positivity on (B, C, F and G).
case_images: JBM-15-123-g0001.jpg
case_images: PMC10941986_02_JBM-15-123-g0001.jpg
case_images: f0001
case_images: Histopathology of the lymph node identified a proliferative process of undetermined nature, with rounded cells and wispy cytoplasm, requiring immunohistochemistry for diagnostic definition, which confirmed the replacement of normal lymph node architecture by histiocyte proliferation, with lymphoplasmacytic infiltrate and emperipolesis, with positivity for S-100, CD68, and sparse CD45, and negative for CD1a, CD207, CD30 (K1-1), clone Ber-H2, CD21 (clone 1F8), CD20 (clone L-26), CD3 (policlonal), CD15 (clone C3D-1), CD117 (clone T595), CD34 (clone BIRMA-K3), CD23 (clone MHM6) (Figure 1).
case_images: PMC10941986_02
case_images: Histopathological findings for patients 1 and 2. (A) Patient 1. Non-neoplastic proliferation showing lymphocyte emperipolesis on 800x increase; (B) Patient 1. Positive immunohistochemistry for CD68 (indicating macrophages) on histiocytic infiltrate; (C) Patient 1. Immunohistochemistry with occasional positivity for S100 on histiocytic infiltrate; (D) Patient 2. Non-neoplastic proliferation showing lymphocyte emperipolesis on 400x increase; (E) Patient 2. Non-neoplastic proliferation showing lymphocyte emperipolesis on 800x increase; (F) Patient 2. Positive immunohistochemistry for CD68 (indicating macrophages) on histiocytic infiltrate; (G) Patient 2. Positive immunohistochemistry for S100; Black arrows indicate emperipolesis on (A, D and E), and indicate immunohistochemistry positivity on (B, C, F and G).
case_images: JBM-15-123-g0001.jpg
case_images: PMC10941986_02_JBM-15-123-g0001.jpg
case_images: f0001
case_images: Histopathology of the lymph node identified a proliferative process of undetermined nature, with rounded cells and wispy cytoplasm, requiring immunohistochemistry for diagnostic definition, which confirmed the replacement of normal lymph node architecture by histiocyte proliferation, with lymphoplasmacytic infiltrate and emperipolesis, with positivity for S-100, CD68, and sparse CD45, and negative for CD1a, CD207, CD30 (K1-1), clone Ber-H2, CD21 (clone 1F8), CD20 (clone L-26), CD3 (policlonal), CD15 (clone C3D-1), CD117 (clone T595), CD34 (clone BIRMA-K3), CD23 (clone MHM6) (Figure 1).