PMC10061010_01
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).
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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.
(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).
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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 ).