Background: Granulocytic sarcoma is a rare malignant extramedullary neoplasm of myeloid precursor cells, occuring before or after onset of leukaemia. Involvement of the head and neck region is rare, generally concerning the orbit.
Aim: To illustrate imaging findings of granulocytic sarcoma in an unusual location; maxillary sinus.
Case: We report a case of maxillary sinus granulocytic sarcoma in a 13-month old boy revealed by facial nerve palsy, ptosis and jugal swelling, without any evidence of haematological disorders. The patient underwent computed tomography and magnetic resonance imaging exam which demonstrated a non specific maxillary sinus mass with destruction of the orbit floor and the alveolar bone. Diagnosis was obtained after bone biopsy allowing histological and immunohistochemical studies.
Conclusion: Granulocytic sarcoma is a serious condition because of the associated hematologic disorders. In a sinus or orbit location, imaging features are non specific. Unless hematologic history is present, diagnosis is difficult and an immuno histo chemical study is required.