title: Unusual endocrine presentations of nasopharyngeal carcinoma.
abstract: BACKGROUND
  Nasopharyngeal carcinoma is endemic in Southern China and the majority of patients present with local symptoms due to the tumor.
  
  
  METHODS
  This report describes two unusual cases of occult nasopharyngeal carcinoma in which the patients initially presented with endocrine manifestations.
  
  
  RESULTS
  The first patient presented with Cushing's syndrome secondary to ectopic adrenocorticotropic hormone (ACTH) production. Nasolaryngoscopy showed a growth in the left nasal fossa and biopsy revealed a poorly differentiated nasopharyngeal carcinoma that exhibited positive immunostaining for ACTH. The second patient presented with a 10-month history of bone pain over both lower limbs. She was normocalcemic but her serum alkaline phosphatase was markedly elevated. A bone biopsy showed both osteoclastic and osteoblastic activity with widespread fibrosis suggestive of Paget's disease. Three months later, she developed third cranial nerve palsy. Computed tomography investigation revealed a soft tissue mass filling the sphenoid and ethmoid sinuses. Biopsy showed a poorly differentiated nasopharyngeal carcinoma. The bone biopsy was reviewed and immunohistochemistry demonstrated the presence of cells positive for the epithelial marker AE1/3 within the fibrous stroma. Radio-labeled in situ hybridization showed that Epstein-Barr virus early RNA was present in these tumor cells and the bone lesions were in fact metastases.
  
  
  CONCLUSIONS
  Nasopharyngeal carcinoma can present with rather atypical symptoms that may lead to a delay in diagnosis. Therefore, in high risk populations, it is important to consider nasopharyngeal carcinoma as a possible primary tumor in patients with occult carcinomas.
authors.affiliation: Department of Medicine, University of Hong Kong, Queen Mary Hospital, Hong Kong.
authors.forename: K C
authors.initials: KC
authors.lastname: Tan
authors.forename: J
authors.initials: J
authors.lastname: Nicholls
authors.forename: A W
authors.initials: AW
authors.lastname: Kung
authors.forename: L
authors.initials: L
authors.lastname: Leong
authors.forename: K S
authors.initials: KS
authors.lastname: Lam
mesh_terms: D000182:ACTH Syndrome, Ectopic / Q000150:complications / Q000175:diagnosis; D000324:Adrenocorticotropic Hormone / Q000032:analysis; D001859:Bone Neoplasms / Q000556:secondary; D003480:Cushing Syndrome / Q000209:etiology; D003937:Diagnosis, Differential; D005260:Female; D004854:Herpesvirus 4, Human / Q000302:isolation & purification; D006801:Humans; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000150:complications / Q000175:diagnosis*; D010001:Osteitis Deformans / Q000175:diagnosis*; D010026:Osteosclerosis / Q000175:diagnosis
chemical_list: D000324:Adrenocorticotropic Hormone