What is the recommended workup for suspected malignancy in an infant?

Recommended Workup for Suspected Malignancy in an Infant

Infants with suspected malignancy should be immediately referred to a pediatric cancer center for prompt and accurate diagnosis and management by a multidisciplinary team with pediatric expertise. 1

Initial Evaluation

• Referral to a pediatric cancer center is essential, as diagnostic accuracy is significantly improved when initial evaluation and biopsy are performed at specialized centers 1
• Diagnostic workup should be coordinated by a board-certified pediatric hematologist/oncologist 1
• The diagnostic biopsy should ideally be performed at the cancer center where specialized facilities are available for all necessary special studies, avoiding the need for repeat procedures 1

Specific Diagnostic Procedures

Clinical Assessment

• Thorough physical examination by a pediatric oncologist to identify specific patterns that may suggest certain malignancies:
  • Distribution and characteristics of skin lesions (bluish papulonodules may suggest neuroblastoma in infants under 3 years) 2
  • Assessment for organomegaly, masses, or lymphadenopathy 1
  • Neurological examination for signs of CNS involvement 1

Laboratory Studies

• Complete blood count with differential 1
• Comprehensive metabolic panel including liver and renal function tests 1
• Tumor markers appropriate for age and suspected malignancy 3

Imaging Studies

• Age-appropriate imaging based on suspected malignancy:
  • Ultrasound as initial imaging modality for abdominal masses 3
  • MRI for central nervous system evaluation when indicated 1
  • Additional imaging (CT, nuclear medicine studies) as directed by initial findings 3

Pathologic Evaluation

• Tissue diagnosis through biopsy performed at the pediatric cancer center 1
• Specialized pathologic assessment including:
  • Immunohistochemistry 1
  • Molecular techniques 1
  • Cytogenetic studies when appropriate 1

Common Malignancies in Infants

• Germ cell tumors (particularly teratomas) and neuroblastoma are the most common tumors in newborns and infants up to 3 months of age 3
• Other malignancies to consider in the differential diagnosis:
  • Central nervous system tumors 3
  • Retinoblastoma 3
  • Hepatoblastoma 3
  • Soft tissue sarcomas 3
  • Leukemias 1

Special Considerations

• Individual approach is warranted for newborns and small infants 3
• Treatment planning must account for the immaturity of tissues and organs in this age group 3
• Genetic counseling should be offered, as some infant malignancies have hereditary components 1
• Consideration of long-term effects of therapy is particularly important in infants 1, 4

Follow-up Care

• Long-term follow-up should be coordinated by the pediatric cancer center 1
• Surveillance for late effects of treatment should be implemented according to exposure-based guidelines 1
• Primary care pediatricians should maintain a supportive role with excellent communication with the oncology team 1

Pitfalls to Avoid

• Delaying referral to a pediatric cancer center can lead to incorrect diagnosis and suboptimal initial management 1
• Performing diagnostic biopsies at non-specialized centers may result in incorrect histologic diagnosis or insufficient tissue for specialized studies 1
• Failure to consider the unique biology of infant malignancies compared to those in older children 3
• Underestimating the importance of specialized pathology expertise in diagnosing rare infant tumors 1