Primary orbital non-Hodgkin's lymphoma.

Non-Hodgkin's lymphoma (NHL) can have extra-nodal presentation in approximately 25% of cases unlike Hodgkin's lymphoma which rarely involves extra-nodal sites. Extra-nodal lymphoma in the head and neck region is extremely rare. We report a case of 6-year-old girl who presented with medial canthus mass with proptosis, lagophthalmos and no significant loss of vision. CT findings showed an extra-conal homogenous mass lesion in the left orbit along superior and medial orbital wall with extensive destruction of surrounding tissue. Histological sections showed polymorphous population of atypical lymphoid cells accompanied by plasma cells, eosinophils and proliferation of small blood vessels with plump endothelial cells. A diagnosis of NHL was rendered. Further, immunohistochemistry confirmed the lesion as peripheral T-cell lymphoma. The lesion was aggressive in course and the patient succumbed within one-and-half months of diagnosis.