Metastatic cellular neurothekeoma arising over a vaccination scar: A case report and literature review.

Cellular neurothekeoma is a rare non-melanocytic skin neoplasm, considered benign and more common in children and young adults, primarily affecting the healthy skin of the head, neck, and scapular region. Based on the morphological findings of the initially reported cases, it was thought to originate from neural sheath cells. Clinical, morphological, and immunohistochemical correlation studies have demonstrated its dermal origin and the absence of neural markers, suggesting a fibrohistiocytic origin, though its histogenesis remains uncertain. They present as slow-growing, self-limiting dermal nodules with exceptional recurrence and very low metastatic potential. We present the case of a child with a reddish, firm, asymptomatic nodule on a vaccination scar on the right shoulder, which was excised, after which an ipsilateral axillary mass developed. The histopathological examination of both lesions revealed a neoplasm with morphological and immunohistochemical characteristics consistent with metastatic cutaneous cellular neurothekeoma in a regional lymph node.