Unusual endocrine presentations of nasopharyngeal carcinoma.

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.