Diagnosis and staging of malignant bone tumours in children: What is due and what is new?

Abstract

Purpose Although malignant bone tumours in children are infrequent, it is important to know how to properly diagnose and stage them, in order to establish an adequate treatment. Methods We present a review of the diagnostic workflow of malignant bone tumours in children, including history and clinical examination, imaging, laboratory tests and biopsy techniques. Moreover, the two most commonly used staging systems are reviewed. Results History, clinical examination and laboratory tests are nonspecific for diagnosing malignant bone tumours in children. Radiographs remain the mainstay for initial diagnosis, with MRI the modality of choice for local assessment and staging. Fluorine-18 labelled fluoro-deoxy-glucose-positron emission tomography scans provide a noninvasive method to assess the aggressiveness of the tumour and to rule out metastasis and is replacing the use of the bone scintigraphy. Biopsy must be always performed under the direction of the surgeon who is to perform the surgical treatment and after all diagnostic evaluation has been done. Staging systems are useful to study the extent of the tumour and its prognosis. They are expected to evolve as we better understand new molecular and genetic findings. Conclusion When a malignant bone tumour is suspected in a child, it is essential to make a correct diagnosis and referral to an experienced centre. Following an appropriate workflow for diagnosis and staging facilitates, prompt access to treatment improves outcomes. Level of Evidence Level V Expert opinion

Imaging Recommendations for Diagnosis, Staging, and Management of Bone Tumors

“…7 Before 5 years of age, a destructive bone lesion is most commonly metastatic neuroblastoma or eosinophilic granuloma; above 5 years, it is often a primary bone sarcoma; after 40 years of age, it tends to be metastasis, myeloma or lymphoma. 8…”

Perspective Chapter: Bone Tumors – How to Make a Diagnosis?

“…History and physical examination are the initial approaches for any patient suspected of having a bone neoplasm (Table 1). Data, such as age (isolated corresponds to the most important data [10]), time of complaint, presence of pain, location of the lesion, and personal and family history of cancer, may provide important information for clinical reasoning and diagnostic management [10][11][12][13]; although the physical examination is generally nonspecific [14]. Often the suspicion of a bone neoplasm occurs only due to an accidental finding of some imaging test [1].…”

“…Every patient with suspected bone neoplasia should be initially evaluated by orthogonal radiography examination and, although the radiologist's report is of great value, the orthopedist must have the basic knowledge to recognize the information that the bone lesion can provide on radiography [10]. The correct diagnostic approach to a bone neoplasm cannot be adequately achieved without radiographic evaluation [14,16,17].…”

“…We can observe if it is bone-forming (osteoblastic), if it promotes bone destruction (osteolytic) or if the lesion has areas of bone formation as well as areas of bone destruction (mixed). Second, the radiography will provide the lesion location (epiphysis, diaphysis, metaphysis, or surface), presence of periosteal reaction (spiculate, sunlight, onion skin, and Codman's triangle), presence of halo of sclerosis, presence of pathological fracture, extension to soft tissues (extra compartmental lesion), among other characteristics specific to each type of bone neoplasm that can even define the diagnosis (Table 2) [10,11,14,18].…”

“…Evaluating structures adjacent to the lesion, such as the extension to soft tissues (most important sign of bone malignancy [16]) and the involvement of neurovascular structures, as well as the extent of spinal cord involvement and the presence of "skip" metastases (present in 25% of osteosarcomas) [14]. The examination should always include the two joints adjacent to the host bone (Figure 2) [10].…”