Intraosseous Neurothekeoma of the Hand in a 16-year-old Boy.

Soft-tissue tumors are rare in the pediatric population. First described in 1969 as myxoma of the nerve sheath, the neurothekeoma is a benign tumor lesion with presumable origin in the nerve sheath. It occurs mainly in female children and presents as a mass of slow, subcutaneous growth, asymptomatic and without alteration of the local pigmentation. It is predominantly located in the head, neck, and extremities of the upper limbs. This report presents the case of a 16-year-old male with a tumor mass originating from the nerve sheath in the 4 th left metacarpal, intraosseous, and relapsed after previous surgical resection 2 years before this observation. A marginal resection of the tumor mass was performed on the distal region of the fourth metacarpal, followed by curettage of the proximal phalanx and filling with structural autologous bone graft. The patient maintained a favorable postoperative clinical evolution, without local pain or range of motion limitation in his fingers. Radiologically, a progressive trabecular filling of the proximal phalanx of the fourth metacarpal was observed. At 17 months of follow-up, the patient is asymptomatic and shows no signs of relapse. The description of this case serves to increase the familiarity with this rare pathology, and aid its diagnosis and treatment.