Atypical Spitz tumors in patients younger than 18 years

Background Diagnosis and proper management of atypical Spitz tumors in pediatric age are still controversial. Objective We sought to investigate the clinicopathological and molecular features of atypical Spitz tumors in patients aged 18 years or younger.Methods We performed a retrospective clinicopathological and fluorescence in situ hybridization study on 50 pediatric atypical Spitz tumors.Results Parameters that were significantly correlated with a diagnosis of atypical Spitz tumors over Spitz nevus included asymmetry, level IV/V, lack of maturation, solid growth, nuclear pleomorphism, high nuclear-cytoplasmic ratio, atypical and deep mitoses, and more than 6 mitoses/mm2. In the atypical Spitz tumors group, a significantly higher mitotic rate was observed in prepuberal age (P =.04). The 4-probe fluorescence in situ hybridization melanoma assay did not discriminate atypical Spitz tumors from Spitz nevi. Heterozygous 9p21 loss was found in 3 of 37 cases and homozygous 9p21 loss in 2 of 37 cases. Only 1 child experienced a fatal outcome, showing genetic abnormalities by melanoma fluorescence in situ hybridization probe and a heterozygous 9p21 deletion.Limitations The limited number of adverse outcomes did not allow the prognostic analysis of single morphologic features. Conclusion Pediatric atypical Spitz tumors are associated with minimal lethal potential. Atypical Spitz tumors require complete excision and careful follow-up while our data do not support any clinical benefit for the sentinel lymph node biopsy procedure and completion lymphadenectomy.