Nasopharyngeal papillary adenocarcinoma. A clinicopathologic study of a low-grade carcinoma.

We present the clinicopathologic features of nine cases of a primary nasopharyngeal (NP) papillary adenocarcinoma. Patients ranged in age from 11 to 64 years (median, 37). The ratio of male to female patients was 5:4. They most frequently presented with airway obstruction. Histomorphologic evaluation showed an invasive carcinoma with papillary and glandular features. The tumor displayed transition from normal surface epithelium to neoplasm. Cytologically it was composed of moderately pleomorphic, columnar, and pseudostratified cells with eosinophilic cytoplasm. The nuclei were round to oval and had vesicular or optically clear chromatin. Histochemical analysis confirmed production of epithelial mucin. Immunohistochemical study demonstrated diffuse keratin and epithelial membrane antigen reactivity and focal carcinoembryonic antigen reactivity. No immunoreactivity was seen with S-100 protein, glial fibrillary acidic protein, or thyroglobulin. Taken together, these findings indicate derivation from the nasopharyngeal surface epithelium and help to differentiate these tumors from seromucous gland lesions and metastatic papillary thyroid carcinoma. The biologic potential was that of a low-grade malignant tumor. Simple and complete surgical excision was the treatment of choice. All patients are presently alive and well, free of recurrent or metastatic tumor (median follow-up, 6 years, 9 months).