A diffuse scalp neurofibroma in a 4-year-old child

BACKGROUND: Structures resembling Meissner's tactile corpuscles have been revealed in various peripheral nerve tumors, including schwannomas and neurofibromas, as well as in congenital melanocytic nevi and neural crest hamartomas. As a rule, Meissner's tactile corpuscles are few in number, but in rare cases they represent the predominant component of the formation tissue.

CLINICAL CASE DESCRIPTION: The authors describe a case of their observation: a 4 y.o. patient with diffuse neurofibroma consisting of structures resembling tactile corpuscles. Clinically, this fibroma looked like a defect in the occipital soft tissue region with excessive folding and alopecia. At the histological examination, the dermis and subcutaneous adipose tissue were seen involved in the pathological process. The formation tissue consisted mostly of "neuroid" structures resembling tactile corpuscles located among fibroblast-like cells with mast cell admixture in the infiltrate. An immunohistochemical examination revealed expression of S100 in them, EMA, GLUT1 in the perineuria, and CD34 in the stroma. Melanocytic marker (MelanA, HMB45) expression was not detected.

CONCLUSION: The case presented by the authors is of interest to professionals due to the rarity of this morphological variant, difficulties of clinical and histological differential diagnostics with other tumors and tumor-like processes in children.