[Case report: pleomorphic adenoma of the lateral nasal wall].

Pleomorphic adenoma is a tumor which most often originates from one of the major salivary glands; it is rarely located in the lacrymal glands and it is highly exceptional in the nasal cavity. Cases of pleomorphic adenoma in the nasal cavity have been described by Spiro (40 cases), Compagno and Wong (40 cases) and Suzuki et al. (41 cases). This type of tumor generally originates from the septal mucosa even though the seromucosal glands are mostly located in the lateral nasal wall. This pathology is more frequently found in females. The clinical signs of this tumor are non specific, slow unilateral nasal occlusion, rhinorrhea and, at times, epistaxis. Evolution is generally local although locoregional and distant metastases have been described in the literature. This sort of tumor has no specific appearance and thus diagnosis is based on histology. Indeed, microscopically nasal pleomorphic adenoma differs from salivary gland adenoma for the predominance of the cellular component over the connective component. The epithelial cells are small, oval-shaped and often arranged in cordons; they are sometimes organized in small acinous structures. The connective component can be mixoid, condroid or collagenous; follicles with squamous metaplasia and mitosis are rare. Histologically differentiating this disorder from olfactory esthesione-uroblastoma can prove difficult; the lack of extra cellular neurifibrillar structures, neurotubules and neurosecretory granules in nasal pleomorphic adenoma are the main distinguishing criteria. The present work reports a case of a 45-year-old man who had suffered of an increasing unilateral nasal obstruction from 1 year. Endoscopic examination showed a smooth surface neoplasm involving the entire nasal cavity. CT scan showed the deformation of the medial bone wall of the maxillary sinus and of the ethmoid although without any osteolysis. Median maxillectomy surgical exeresis of the neoplasm was performed with the facial degloving technique. Histology revealed a 5 cm pleomorphic adenoma originating from the lateral nasal wall. This origin is extremely rare because this tumor generally originates in the nasal septum. Immunohistochemical stains proved positive for epithelial membrane antigen (MNF 116), for myoepithelial cells (PS100) and for stromal cells (Vimentine) with the epithelial elements predominating. After 9 months of follow-up the patient is still disease free.