case_images: PMC10469918_01
case_images: The axial image of T1-weighted (A), Fat-suppressed T2-weighted (B), diffusion-weighted (C), and gadolinium-enhanced T1-weighted (D) MRI images showed massive splenomegaly with an abnormal signal lesion (arrows) in the spleen. The HE staining specimen of spleen (E) showed diffuse distribution of small to medium monomorphic round cells with moderate cytoplasm and inconspicuous nucleoli, and the neoplastic cells showed both positive for CD56 (F) and CD123 (G) in immunohistochemistry.
case_images: fmed-10-1258310-g001.jpg
case_images: PMC10469918_01_fmed-10-1258310-g001.jpg
case_images: fig1
case_images: Contrast-enhanced magnetic resonance imaging (MRI) revealed massive splenomegaly with an abnormal signal lesion in the spleen (Figures 1A-D), and multiple enlarged lymph nodes in the hepatic hilum and around the pancreas. Hematoxylin and eosin (HE)-stained specimens of the splenic lesion revealed diffuse distribution of small to medium monomorphic round cells with moderate cytoplasm and inconspicuous nucleoli, and the result of immunohistochemistry (IHC) showed CD56 (++), CD123 (+), CD4 (++), CD43 (++), which was consistent with BPDCN involving the spleen (Figures 1E-G).
case_images: The physical examination revealed a brown rash on the patient's left cheek [(A), arrow]. The axial image of head CT revealed slightly skin thickening in the left cheek [(B), arrow], with mild 18F-FDG avidity (SUVmax 1.1) on the corresponding PET [(C), arrow] and PET/CT fusion [(D), arrow] images. The body MIP image (E) demonstrated diffuse 18F-FDG uptake in bone marrow (SUVmax 4.0) and multiple metabolic foci as described in the following axial images. On the axial images of PET, CT and PET/CT fusion, multiple enlarged lymph nodes were found in bilateral submaxillary regions (F), bilateral axillas and mediastinum (G), hepatic hilum (H), and bilateral groins (I) (arrows), which exhibited varying 18F-FDG avidity with the maximal SUVmax of 4.2 in the left submaxillary lymph nodes.
case_images: fmed-10-1258310-g002.jpg
case_images: PMC10469918_01_fmed-10-1258310-g002.jpg
case_images: fig2
case_images: Further physical examination revealed a brown rash on the patient's left cheek (Figure 2A), and 18F-FDG PET/CT was performed for evaluating the systemic involvement of BPDCN. The images revealed slightly skin thickening in the left cheek with mild 18F-FDG avidity with maximum standardized uptake value (SUVmax) of 1.1 (Figures 2B-D), diffuse uptake in the bone marrow with SUVmax of 4.0, and multiple metabolic enlarged lymph nodes with SUVmax of 4.2 (Figures 2E-I).
case_images: The second 18F-FDG PET/CT was performed 4 months after the HSCT. The MIP image (A) showed multiple new 18F-FDG-avid lesions in the chest and abdomen, while the previous hypermetabolic lesions all disappeared. On the axial images of PET, CT and PET/CT fusion, enlarged lymph nodes were observed in mediastinum (B,C), and abdominal and pelvic cavity (D,E) (arrows), which demonstrated intense 18F-FDG uptake with the highest SUVmax of 13.9 in the mesenteric lymph node.
case_images: fmed-10-1258310-g003.jpg
case_images: PMC10469918_01_fmed-10-1258310-g003.jpg
case_images: fig3
case_images: The images showed multiple new 18F-FDG-avid enlarged lymph nodes in the chest and abdomen with SUVmax of 13.9, while the previous hypermetabolic lesions all disappeared (Figure 3).
case_images: The pathology of the mesenteric lymph node. The HE staining specimen (A) showed diffuse medium-large cell infiltration with nuclear irregularity. Immunophenotype of the neoplastic cells showed CD20 (B) and Bcl-2 (C) were positive, while CD56 (D) and CD123 (E) were negative. The in-situ hybridization (ISH) staining of EBV-encoded RNA [EBER, (F)] showed EBV positive.
case_images: fmed-10-1258310-g004.jpg
case_images: PMC10469918_01_fmed-10-1258310-g004.jpg
case_images: fig4
case_images: The HE result showed diffuse medium-large cell infiltration with nuclear irregularity, and the IHC results showed CD20 (+++), CD3 (-), CD56 (-), CD10 (-), Bcl-6 (-), MUM1 (+), Bcl-2 (80%+), CD123 (-), with EBV-positive in the in-situ hybridization for EBV-encoded RNA (Figure 4).