Nasal chondromesenchymal hamartoma of infancy: The first Japanese case report

The first Japanese case of nasal chondromesenchymal hamartoma, a rare infan tile nasal neoplasm, is presented, A 4-month-old Japanese boy was referred to our Centre because of intranasal mass and oculomotor disturbance. Radiol ogical images showed the intranasal tumor extending to the paranasal sinus, orbit, and anterior frontal fossa. Subtotal resection and radiation therap y to residual tumor were performed. There has been no recurrence of the tum or for 13 years. Histologically, the lesion demonstrated admixture of vario us mesenchymal elements, including cellular spindle cell stroma with occasi onal myxoid change, nodules of mature/immature cartilaginous tissue, focal osteoclastlike giant cells, and erythrocyte-filled spaces resembling aneury smal bone cyst. The histology was consistent with the findings presented by McDermott et al, 1986, Immunohistochemically, the spindle cells were posit ive for vimentin and smooth muscle actin. Chondrocytes in the mature cartil aginous tissue were positive for S-100 and vimentin; chondrocytes in the im mature cartilaginous tissue were positive for S-100, vimentin, and smooth m uscle actin, Ultrastructurally, the spindle cells showed features of either fibroblast or myofibroblast.