Dermatology: Practical and Conceptual Image Letter | Dermatol Pract Concept. 2024;14(3):e2024199 1 Rare Case of Cellular Neurothekeoma in an Infant with an Asymptomatic Abdominal Nodule Tullio Brunetti1,2, Marco Adriano Chessa1,2, Annalucia Virdi1, Iria Neri1 1 Dermatology Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy 2 Department of Medical and Surgical Sciences, Alma Mater Studiorum University of Bologna, Italy Citation: Brunetti T, Chessa MA, Virdi A, Neri I. Rare Case of Cellular Neurothekeoma in an Infant With an Asymptomatic Abdominal Nodule. Dermatol Pract Concept. 2024;14(3):e2024199. DOI: https://doi.org/10.5826/dpc.1403a199 Accepted: February 28, 2024; Published: July 2024 Copyright: © Brunetti et al. This is an open-access article distributed under the terms of the Creative Commons Attribution- NonCommercial License (BY-NC-4.0), https://creativecommons.org/licenses/by-nc/4.0/, which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original authors and source are credited. Funding: None. Competing Interests: None. Authorship: All authors have contributed significantly to this publication. Corresponding Author: Marco Adriano Chessa, Department of Dermatology, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Via Massarenti 1, 40138 Bologna, Italy. Telephone: 0512144843 Email: marcoadriano.chessa@gmail.com Case Presentation A 5-month-old healthy male presented with a 3-month history of a small nodule on the skin of the trunk. Physical examina- tion revealed a pink nontender roundish domed nodule with a smooth surface and a stretched texture 6 mm in diameter on the midline of the abdomen (Figure 1). The differential diagno- sis included Spitz nevus, fibrous tumor, and xanthogranuloma. Dermoscopy revealed a whitish pink non-structured central area with dilated linear irregular unfocused vessels peripherally. Histological examination showed a mesenchymal neoplasm with the WHO 2018/2023 spectrum of histological features and immunophenotypic profile of cellular neurothekeoma. Teaching Point Cellular neurothekeoma (CN) is an uncommon benign soft tissue dermal neoplasm. It can occur on any cutaneous location but is commonly seen on the upper limbs of young children and adolescents [1]. CN tumors show increased cellularity, a lack of myxoid stroma, negativity to S100 protein, and often positivity to NK1C3 (CD57). Unlike the classical type of neurothekeoma (nerve sheath myxoma) in the cellular variant of the tumor, a histiocytic or fibro- histiocytic differentiation has been suggested by recent evidence. Dermatoscopic diagnosis is challenging because CN is not distinctive, featuring arborizing vessels on a reddish background, whitish streak areas, or peripheral pigment net- work. So, it is often mistaken for basal cell carcinoma or dermatofibroma [2]. In conclusion, although it is rare to see a CN in infancy, it is important to keep in mind this kind of tumor in the differential diagnosis of nodular lesions in pediatric age. It is crucial to recognize this entity in children to prevent misdi- agnosis and excessively aggressive treatments. 2 Image Letter | Dermatol Pract Concept. 2024;14(3):e2024199 References 1. Murphrey M, Huy Nguyen A, White KP, Krol A, Bernert R, Yarbrough K. Pediatric cellular neurothekeoma: Seven cases and systematic review of the literature. Pediatr Dermatol. 2020;37(2):320-325. doi:10.1111/pde.14043 Figure 1. (A) Photo of neurothekeoma. (B) Videodermoscopy scan. (C) Histology. 2. Choi S, Cho SI, Lee C, Kwak Y, Mun JH. Dermoscopy of multiple cellular neurothekeoma: An analysis of 11 neurothekeomas in a middle-aged woman. Australas J Dermatol. 2020;61(1):e73-e76. doi:10.1111/ajd.13185