Giant-cell-rich pseudotumour in Paget's disease

Area of Science:

• Orthopedic Oncology
• Bone Pathology
• Skeletal Radiology

Background:

• Paget's disease of bone (PD) is a chronic disorder characterized by abnormal bone remodeling.
• Malignant transformation to sarcoma in PD is recognized, but benign pseudotumors are less commonly discussed.
• Giant-cell-rich lesions can occur in bone and soft tissues, necessitating accurate differential diagnosis.

Observation:

• A case of polyostotic Paget's disease presented with a large, giant-cell-rich pseudotumor in the tibia and surrounding soft tissues.
• Histological examination revealed highly vascularized tissues with significant hemorrhage, new bone formation, and diffuse osteoclastic giant cells.
• The pseudotumor demonstrated benign behavior, with no recurrence or metastasis observed 3 years post-excision.

Findings:

• Paget's disease can manifest as a benign, giant-cell-rich pseudotumor.
• These pseudotumors exhibit characteristic histological features including vascularity, hemorrhage, and giant cells.
• The lesion's benign nature was confirmed by the absence of recurrence or metastasis after surgical removal.

Implications:

• Clinicians must consider benign giant-cell-rich pseudotumors as a potential complication of Paget's disease.
• Accurate differentiation from other giant-cell-rich bone and soft tissue tumors is crucial for appropriate patient management.
• Awareness of this benign entity can prevent misdiagnosis and unnecessary aggressive treatment.