Diagnostic Dilemma of Osteoblastoma-like Osteosarcoma in a Pediatric Patient: A Case Report

Introduction: Osteoblastoma-like osteosarcoma is a rare subtype of osteosarcoma, constituting only 1% cases. Due to its similarity with osteoblastoma in clinical, radiological, and pathological features, distinguishing between the two can be challenging. This study reports a rare case of osteoblastoma-like osteosarcoma in a 12-year-old girl, emphasizing the diagnostic challenges and the critical role of immunohistochemistry (IHC) in confirming the diagnosis. Case Presentation: A 12-year-old girl presented with pain and swelling in her right knee after a fall. Initially, the symptoms had been present for 6 months, with worsening pain over the last 2 months, requiring the use of a walking crutch. MRI findings raised suspicion of a Giant Cell Tumor (GCT), but core biopsy results suggested osteoblastoma-like osteosarcoma. Immunohistochemistry (IHK) for P53 was strongly positive, further supporting the diagnosis of osteoblastoma-like osteosarcoma. Clinical Discussion: Osteosarcoma and osteoblastoma-like osteosarcoma share many similarities, making diagnosis difficult. A thorough clinical evaluation, advanced imaging, and histopathological analysis, including IHC, are crucial for an accurate diagnosis. This case highlights the importance of a multidisciplinary approach, involving clinicians, radiologists, and pathologists, to establish the correct diagnosis and determine an appropriate treatment plan. Conclusion: Osteoblastoma-like osteosarcoma is a rare and challenging tumor to diagnose due to its similarity with other bone lesions. A multidisciplinary approach, along with the use of immunohistochemistry, is essential for accurate diagnosis and effective treatment. Keywords: immunohistochemistry, osteoblastoma, osteosarcoma