Pediatric cellular neurothekeoma: Seven cases and systematic review of the literature

Background/Objectives: Neurothekeoma is a rare, benign, cutaneous neoplasm consisting of Schwann cells and perineural cells in myxoid stroma. Cellular neurothekeoma (CNT) was previously thought to represent a morphologic variant of neurothekeoma, but recent studies have shown that CNTs are unrelated to neurothekeomas and are more likely of histiocytic lineage. Methods: Herein, we describe seven cases of CNT in pediatric patients. A comprehensive search of PubMed was performed, and 71 cases of cellular neurothekeoma in pediatric patients were reviewed. Results: The clinical differential diagnosis for these lesions included Spitz nevi, keloid, juvenile xanthogranuloma, cutaneous lymphoid hyperplasia, and lymphomatoid papulosis. All cases were treated by excision or excisional biopsy. Histopathologically, all demonstrated multilobular, primarily intradermal neoplasms composed of plump spindled or epithelioid mononuclear cells with abundant eosinophilic pale-staining cytoplasm. Immunophenotypic findings included CD68 and NKI/C3 positivity, and negative staining with cytokeratin, S-100, Melan-A, and SOX-10. Conclusion: Cellular neurothekeoma is distinguished from conventional neurothekeoma by increased cellularity, a lack of myxoid stroma, and a lack of neural expression with immunohistochemical stains. These uncommon neoplasms should be included in the differential diagnosis of dermal nodules in children. Accurate diagnosis of these lesions is essential, as they can be mistaken for malignancy leading to unnecessary treatment.