Overview
Definition:
Primary bone tumors in adolescents are a heterogeneous group of neoplasms originating from bone or cartilage
Persistent, worsening, or nocturnal bone pain in this age group can be a critical red flag for malignancy
Early recognition is vital for optimal outcomes.
Epidemiology:
While rare, primary bone tumors are the most common solid tumors in childhood and adolescence, with osteosarcoma and Ewing sarcoma being the most prevalent malignant types
The incidence peaks in the second decade of life
Boys are slightly more affected than girls.
Clinical Significance:
Timely diagnosis of malignant primary bone tumors in adolescents is paramount as these are often aggressive and can metastasize, particularly to the lungs
Delays in diagnosis can significantly impact prognosis, leading to poorer survival rates and increased morbidity.
Clinical Presentation
Symptoms:
Persistent, progressive bone pain, often worse at night and interfering with sleep
Limping or difficulty bearing weight on the affected limb
A palpable mass or swelling over the bone
Recent fracture with minimal or no trauma (pathologic fracture)
Systemic symptoms like fever, weight loss, or fatigue may be present, especially in Ewing sarcoma.
Signs:
Palpable mass which may be firm, tender, or fixed
Swelling and erythema over the affected area
Limited range of motion in adjacent joints
Tenderness to palpation over the affected bone
Examination for distant metastases, particularly lung auscultation and abdominal palpation.
Diagnostic Criteria:
There are no specific universally adopted diagnostic criteria for red flags themselves
diagnosis relies on high index of suspicion and prompt investigation when these red flags are present in the context of bone pain in an adolescent
Definitive diagnosis requires histological confirmation.
Diagnostic Approach
History Taking:
Detailed pain characterization: onset, duration, severity, nocturnal exacerbation, alleviating/aggravating factors
History of trauma (though often minor or irrelevant in malignant tumors)
Presence of systemic symptoms (fever, weight loss)
Previous history of bone disease or malignancy
Family history of cancer.
Physical Examination:
Systematic examination of the affected limb, including assessment of range of motion, presence of swelling, tenderness, erythema, and neurological deficits
Palpation for masses
Examination of regional lymph nodes
Full systemic examination to assess for signs of metastasis.
Investigations:
Plain radiographs: Initial imaging modality to assess bone lesions, cortical integrity, periosteal reaction (e.g., Codman triangle in osteosarcoma, onion-skinning in Ewing sarcoma)
Magnetic Resonance Imaging (MRI): Gold standard for local staging, assessing soft tissue extension, skip lesions, and joint involvement
Computed Tomography (CT) scan: Useful for evaluating cortical destruction and pulmonary metastases
Bone scan (Technetium-99m scintigraphy): Detects multifocal disease and skeletal metastases
Complete Blood Count (CBC), Erythrocyte Sedimentation Rate (ESR), C-Reactive Protein (CRP): May be elevated, especially in Ewing sarcoma
Serum alkaline phosphatase and lactate dehydrogenase (LDH): Can be elevated in osteosarcoma and Ewing sarcoma respectively, and are useful prognostic markers
Biopsy: Essential for definitive diagnosis and histological subtyping
usually performed after imaging has been completed to avoid contaminating potential surgical planes.
Differential Diagnosis:
Benign bone tumors (osteochondroma, osteoid osteoma, enchondroma)
Bone cysts (simple or aneurysmal)
Osteomyelitis (bone infection)
Juvenile idiopathic arthritis
Trauma (fractures, contusions)
Stress fractures
Myositis
Referred pain from other sources.
Management
Initial Management:
Prompt referral to a pediatric oncologist or orthopedic oncologist
Pain management with analgesics
Avoidance of weight-bearing on the affected limb if fracture is suspected or present
Stabilization of pathologic fractures if necessary.
Medical Management:
Primarily chemotherapy for malignant tumors like osteosarcoma and Ewing sarcoma
Neoadjuvant chemotherapy (before surgery) and adjuvant chemotherapy (after surgery) are standard protocols
Specific regimens depend on tumor type, stage, and histology (e.g., doxorubicin, cisplatin, cyclophosphamide, etoposide).
Surgical Management:
Surgical resection is a cornerstone of treatment for most primary bone tumors
Limb-salvage surgery with reconstruction is preferred when possible, aiming to preserve limb function
Amputation may be necessary for extensive tumors, unresectable lesions, or when limb salvage is not feasible
The goal is wide en bloc resection with clear margins.
Supportive Care:
Nutritional support is crucial, especially during chemotherapy
Psychological support for the patient and family
Physiotherapy and occupational therapy for rehabilitation post-surgery
Management of treatment-related side effects.
Complications
Early Complications:
Surgical site infection
Delayed wound healing
Anesthesia-related complications
Pathologic fracture during or after biopsy/treatment
Neurological injury during surgery
Severe myelosuppression from chemotherapy leading to infections and bleeding.
Late Complications:
Metastatic disease (most commonly to the lungs)
Limb length discrepancy or deformity after limb salvage surgery
Joint stiffness and loss of function
Osteonecrosis
Secondary malignancies due to chemotherapy or radiation
Psychosocial challenges and body image issues.
Prevention Strategies:
Adherence to strict sterile techniques during biopsy and surgery
Judicious use of weight-bearing restrictions
Prophylactic antibiotics in specific surgical scenarios
Careful surgical planning for limb salvage
Early and aggressive management of chemotherapy side effects
Comprehensive rehabilitation program
Regular surveillance for recurrence and metastasis.
Prognosis
Factors Affecting Prognosis:
Histological type and grade of the tumor
Tumor stage at diagnosis (presence of metastasis)
Response to neoadjuvant chemotherapy
Completeness of surgical resection (margin status)
Patient's age and overall health
Location of the tumor.
Outcomes:
Prognosis varies significantly
For localized osteosarcoma, 5-year survival rates can range from 60-80% with modern multimodal treatment
Ewing sarcoma has a slightly lower survival rate, especially with metastatic disease
Early diagnosis and aggressive treatment are key to improving outcomes.
Follow Up:
Long-term follow-up is essential, typically involving regular clinical examinations, chest imaging (X-rays and CT scans), and bone scans to monitor for recurrence or metastasis
Follow-up may extend for many years, often for life, to monitor for late complications.
Key Points
Exam Focus:
DNB/NEET SS exams frequently test the red flags of bone pain in adolescents: nocturnal pain, progressive worsening, pain with activity, limping, palpable mass, and pathologic fracture
Key malignant differentials are osteosarcoma and Ewing sarcoma
Imaging findings like Codman triangle and onion-skinning are important.
Clinical Pearls:
Never dismiss persistent bone pain in an adolescent as "growing pains" without thorough evaluation
A high index of suspicion is crucial
Early referral to a specialist can dramatically alter the prognosis
Understand that biopsy should be performed by the surgical team who will ultimately resect the tumor to minimize contamination.
Common Mistakes:
Attributing all bone pain to benign causes without adequate investigation
Delaying referral to pediatric oncology or orthopedic oncology
Inadequate imaging before biopsy
Performing a biopsy in a way that compromises future surgical resection
Underestimating the risk of malignancy in adolescent bone pain.