Does a changing spitzoid nevus (pigmented mole) in a 3-year-old child that has transformed into a pink papule require a biopsy?

Management of Changing Spitzoid Nevus in a 3-Year-Old

A changing spitzoid nevus in a 3-year-old child that has transformed into a pink papule should undergo complete excisional biopsy with narrow margins to rule out atypical Spitz tumor or spitzoid melanoma. 1

Rationale for Biopsy

• Spitzoid lesions with changing characteristics (color, size, shape) raise concern for potential malignancy, especially when transforming into pink papules
• While typical Spitz nevi are considered benign and occur predominantly in children, atypical Spitz tumors have uncertain malignant potential 1
• Differentiation between Spitz nevi and spitzoid melanoma remains difficult even for experienced dermatopathologists 1
• The clinical implications of missing a melanoma are significant, as failure to recognize melanomas can lead to inadequate excisions and recurrence of a neoplasm with potential to metastasize 1

Diagnostic Approach

1. Complete excisional biopsy with narrow margins is recommended

   • The American Academy of Dermatology recommends excisional biopsy with narrow margins for all cutaneous lesions suspected to be melanoma 1
   • Typical Spitz nevi should generally be completely excised with narrow margins 1
   • This approach provides the most complete histopathologic assessment without compromising future wider excision if needed

2. Histopathologic evaluation should include:

   • Assessment for architectural features (asymmetry, lack of circumscription, lack of maturation)
   • Cytological features (deep dermal mitosis, frequent mitosis, high-grade cytological atypia)
   • Immunohistochemical features (p16Ink4a, dual-color Ki67/MART-1, and HMB45) 1

Special Considerations for Pediatric Patients

• Children younger than 18 years have been excluded from virtually all prospective studies of melanoma excision margins 1
• Spitzoid lesions may have diverse dermoscopic patterns: vascular, starburst, globular, atypical, reticular, negative homogeneous, or targetoid 2
• Atypical histopathologic features are common in benign melanocytic nevi of young children and do not necessarily indicate malignancy 3
• Pagetoid growth and/or melanin deposits in the keratin layer are significantly higher in young children and may not indicate malignancy 4

Management After Biopsy

• If histopathology confirms a typical Spitz nevus with clear margins, no further intervention is needed
• If histopathology reveals an atypical Spitz tumor:
  • Consider additional molecular testing (FISH with five probes: 6p25, 8q24, 11q13, CEN9, and 9p21) 1
  • For atypical and malignant lesions in young children (<14 years), a 1-cm margin is recommended regardless of measured thickness 1
  • Sentinel lymph node biopsy may be considered for lesions 1 mm and larger in thickness when melanoma cannot be excluded 1

Common Pitfalls to Avoid

1. Misdiagnosing based on clinical appearance alone

   • Clinical differentiation between benign Spitz nevi and spitzoid melanoma is often impossible
   • Histopathologic examination is essential

2. Overtreatment of benign lesions

   • Labeling a benign lesion as malignant can lead to morbidity from unwarranted wide re-excisions 1
   • Routine re-excision of all atypical nevi with mild atypia is unnecessary 5

3. Undertreatment of potentially malignant lesions

   • Observation without biopsy of changing spitzoid lesions may miss early melanoma
   • Surgical excision is recommended for clinically atypical spitzoid lesions of childhood 6

4. Inadequate biopsy technique

   • Shave biopsies may not provide adequate tissue for complete histopathologic assessment
   • Excisional biopsy is preferred for accurate diagnosis and staging if needed

By following this approach, you can ensure proper diagnosis and management of this concerning lesion while minimizing both the risk of missing a malignancy and the risk of overtreatment.