A 49-year-old women presented to the emergency department in April 2005 with right-side epistaxis and a 2-year history of progressive right-side nasal obstruction and anosmia, and a visible mass in the right nasal cavity. The rest of the history and physical examination revealed a history of meningitis and respiratory tuberculosis in infancy and a caesarean section. She had normal neurological and ophthalmological exams and no cutaneous lesions or lymph node enlargement.
CT and MRI scans were conducted, which showed a lesion occupying the right nasal fossa with maxillary sinus involvement that extended from the piriform aperture to the cavum and was in contact with the orbital contents (absence of the lamina papyracea) and the dura in the region of the cribriform plate (Fig. 1).
Because several different types of malignancy were possible (rhabdomyosarcoma, neuro-endocrine tumour, neuroblastoma, and chordoma), a biopsy was performed under local anaesthesia during her hospitalisation; however, the histological findings were inconclusive. Therefore, another biopsy was performed under general anaesthesia, and the biopsy sample was sent to the central histopathology department in France (Hospital Lariboisere).
The microscopic examination showed a very cellular tumour containing spindle-shaped cells with oval and comma shaped nuclei. Eosinophilic cytoplasm was also observed. This aspect was associated with well-differentiated muscle fascicles with a very low mitotic index (1 mitosis per 10 high-power fields).