Primitive Myxoid Mesenchymal Tumour of Nose.

Abstract

Primitive Myxoid Mesenchymal Tumour of Infancy (P.M.M.T.I.) is a locally aggressive myofibroblastic tumour, occurring mostly in the first year of life. Grossly, it occurs as a non-encapsulated, multi-nodular tumour with focal infiltrative growth with a size ranging from 2 to 15cm. It is composed of primitive spindled cells in a myxoid background. It is a low-grade fibroblastic malignancy with low metastatic potential with a high local recurrence rate. On immunohistochemistry, it stains positive for Vimentin. no reactivity for smooth muscle actin, muscle specific actin, desmin, S-100 protein, or myogenin. Electron microscopy documented a poorly differentiated fibroblastic proliferation. The present case is of a P.M.M.T. occurring in the nose of a 3 ½ years old female child. This is the first case reported from Central India. The child had recurrent nasal growth and the excision biopsy was suggestive of intermediate grade fibroblastic neoplasm. The biopsy, on IHC staining, was positive for Vimentin and CD99 and negative for S-100, CD-34 and Desmin, favouring the diagnosis of P.M.M.T. The child had a total of three recurrence of growth after local excision before diagnosis was established. In the prior two surgeries, the histopathological analysis reported it as a benign nasal polyp. After the third surgery, the specimen was sent for IHC. Immunohistochemical stains helped in differentiating it from congenital infantile fibrosarcomas, a similar type of mesodermal tumour. The present case of Primitive myxoid mesenchymal tumour following IHC stains were positive for Vimentin, CD-99, CD-117 and NESTIN, pointing to the primitive nature of the tumour. It was negative for the neural marker. Since it is chemo resistant, the preferred method of treatment is wide surgical excision.