case_images: PMC10061010_01
case_images: X-ray demonstrates displaced mid femoral pathologic fracture through a permeative lesion with improved alignment and diffuse osteopenia (A). Axial images from CT of the left lower extremity showing a pathologic fracture involving the left proximal femur with sclerotic and fragmented bones (arrow in (B), and a large heterogeneous soft tissue density mass surrounding the bone fragments (arrow in (C). Whole-body image from the FDG PET/CT scan (D) shows intense hypermetabolism in the left thigh mass, consistent with neoplastic involvement. Other foci of increased uptake were thought to be non-neoplastic. The pathologic fracture has been internally fixed with an intramedullary nail (arrow in (E), and the axial fused PET/CT image shows intense hypermetabolism in the mass surrounding the proximal femur (arrow in (F).
case_images: fonc-13-1100559-g001.jpg
case_images: PMC10061010_01_fonc-13-1100559-g001.jpg
case_images: f1
case_images: Left lower extremity x-ray showed an irregular 2.5-mm displaced left femur shaft fracture with a "moth-eaten" appearance consistent with PF ( Figure 1A ). A large heterogeneous surrounding soft tissue enhancement was noted, representing a possible soft tissue lesion vs. hematoma ( Figures 1B-D ). Magnetic resonance imaging (MRI) was planned for the left leg, but the patient first underwent intramedullary nail fixation and reduction, during which a repeat and conclusive intraoperative left femur reaming biopsy was taken ( Figures 1E, F ). Figures 1D-F ). Fluorodeoxyglucose (FDG) uptake of gastrointestinal sites prompted evaluation by esophagogastroduodenoscopy and colonoscopy, which showed no evidence of malignancy.
case_images: (A) Histopathological examination of showed focally necrotic and fibrotic diffuse lymphoid infiltrate surrounding bone trabecular (H&E, 200x). Immunohistochemistry showing strongly positive staining for CD20 (B), 200x), CD10 (C), 200x), and PAX-5 (D), 200x).
case_images: fonc-13-1100559-g002.jpg
case_images: PMC10061010_01_fonc-13-1100559-g002.jpg
case_images: f2
case_images: Histological and immunohistochemical (IHC) evaluation identified a focally necrotic, atypical lymphoid population positive for CD10 (>30%), CD20, CD45, PAX-5, Bcl-2 (>50%), and Bcl-6 (>30%) ( Figure 2 ).