Cytologic features of metastatic nasopharyngeal carcinoma

The aim of the study was to describe the cytologic features of metastatic nasopharyngeal carcinomas (NPC) to lymph node, which would help in arriving at a definite diagnosis, particularly in cases of occult primary with predominant finding of cervical lymphadenopathy. This is a retrospective study over a period of 2 yr (January 2000 to December 2001) and included 15 cases of NPC metastasizing to cervical lymph nodes. All cases had histopathologic diagnosis of primary NPC. Two independent observers studied detailed cytomorphology of these cases. The FNAC smears were cellular and except for three cases revealed predominantly discohesive malignant cells admixed with lymphocytes. Cellular degeneration and naked tumor cell nuclear were seen in all cases. The tumor cells showed mild to moderate nuclear pleomorphism, vesicular chromatin, and scanty cytoplasm with ill-defined cytoplasmic borders. All 15 cases were typed according to the World Health Organization (WHO) classification as types I, II, and III NPCs. There were two cases of type I NPCs, five cases of type II, and eight cases of type III pattern. FNAC of metastatic NPC in lymph node is a valuable diagnostic modality in suggesting the site of origin of the tumor. Furthermore, it is also helpful to exclude residual disease and recurrence in a treated patient with lymphadenopathy.