Nasal chondromesenchymal hamartoma in children: report of 2 cases with review of the literature.

Hamartoma in the nasal cavity of children is especially rare. Most documented cases occurred in infants, with characteristic histologic features of a mixture of various mesenchymal tissues. McDermott et al designated it nasal chondromesenchymal hamartoma in 1998, and it has since been considered a distinct clinicopathological entity. We report 2 such examples in a full-term male newborn and a 9-month-old boy, respectively. Histologically, both cases were characterized by a mixture of various mesenchymal elements, including spindle cells, collagen fibers, and irregular islands of osseous and chondroid tissue. Immunohistochemical study showed positivity to vimentin and S100 protein. Ultrastructural examination of case 1 demonstrated fibroblastic and myofibroblastic differentiation in tumor cells. There were 11 cases of nasal chondromesenchymal hamartoma in children published to date. The tumor has a benign biological behavior, and complete resection is the treatment of choice. It is apt to be misdiagnosed because of overlapping histologic features shared with a number of benign and malignant soft tissue tumors. Awareness of this entity is essential for correct diagnosis and adequate therapy.