Atypical Spitz Tumor With RET::MXT1 Gene Rearrangement in a 14-Year-Old Girl: An Integrated Histopathologic, Immunohistochemical, and Molecular Diagnostic Approach.
A Di Lorito, A Capo, L Ucci et al.
✦ AI-curated · Sources linked
Case in brief
A 14-year-old girl presented with a changing pigmented lesion on her upper back. Histopathological analysis revealed an asymmetric melanocytic proliferation with epithelioid cells and limited mitotic activity. Immunohistochemistry showed positive Melan-A and SOX10, retained p16, and a gradient HMB45 pattern. Next-generation sequencing identified a RET::MXT1 gene fusion, aiding in the diagnosis and classification of the atypical Spitz tumor.
What made this case unusual
This case is notable for the identification of a RET::MXT1 gene fusion, which has not been previously reported in atypical Spitz tumors.
Diagnostic / clinical pearl
An integrated approach combining histopathology, immunohistochemistry, and molecular diagnostics is essential for accurate classification of atypical Spitz tumors in pediatric patients.
Why it matters
The identification of specific gene fusions like RET::MXT1 can enhance risk stratification and inform clinical management strategies for atypical spitzoid lesions.