Chondromyxoid fibroma affecting the maxilla in a 1-year-old child: Immunohistochemical analysis and literature review.

Chondromyxoid fibroma (CMF) is a benign chondroid/myxoid matrix-producing tumor that often develops in the long bones of young adults. CMF is rarely reported in the craniofacial skeleton, with most cases presenting with bone erosion or destruction, which may lead to a misdiagnosis. To date, approximately 129 cases of CMF in the craniofacial region have been reported, with only three cases in patients aged less than 1 year. Of these 129 cases, only 34 affected the jaws. A 1-year-old boy presented with a mass in the left anterior maxilla, extending and compressing the ipsilateral nasal cavity. After surgical excision of the lesion, microscopy revealed spindle-to-stellate tumor cells surrounded by a predominant myxoid stroma containing focal slit-like vascular channels and hemorrhagic areas. Immunohistochemistry showed positivity for vimentin, CD10, and α-SMA (focal). The Ki-67 labeling index was 6%. CFM should be included in the differential diagnosis when assessing maxillary tumors in pediatric patients.