Undifferentiated Type Nasopharyngeal Carcinoma With Rare Periportal Lymph Node Metastasis

Abstract

Nasopharyngeal carcinoma (NPC) is an aggressive Epstein Barr virus (EBV) associated carcinoma accounting for 3.7% of upper aerodigestive tract malignancies. At presentation, most patients (60-72%) demonstrate cervical lymphadenopathy, and 5-11% will have clinically apparent distant metastases, with 78% developing distant metastatic disease within 18 months of presentation. The most common sites for distant metastases are bone, liver, lung, and bone marrow. We present a 38-year-old man with a right nasopharyngeal mass, ipsilateral cervical lymphadenopathy, and enlarged periportal lymph node. Neck and chest computed tomography scan revealed a 1.8 cm hypodense mass in the right lateral parapharyngeal space with right posterior cervical adenopathy. Positron emission tomography scan showed increased fludeoxyglucose uptake in the neck and in the porta hepatis region. The patient underwent palpation guided fine needle aspiration biopsy (FNA) from the neck mass, core needle biopsies of the right nasopharyngeal mass, bilateral tonsillectomy, and right neck dissection. The FNA, nasopharyngeal biopsies, and right neck levels 2a, 3 and 4 lymph nodes showed nonkeratinizing NPC, undifferentiated type (WHO type III), which was confirmed by strong nuclear positivity for EBV by in situ hybridization and focal positive immunohistochemical staining for cytokeratins AE1:AE3 and CAM5.2. Negative immunohistochemistry included CK5/6, P63, CK903, EMA, CD45, CD20, CD3, CD4, CD5, CD138, FLI1, MUM1, PAX5, vimentin, desmin, S100, melan A, HMB45, and SMA. Both tonsils and all level 2b lymph nodes were negative for carcinoma. Due to the unusual location, the periportal lymph node was sampled to rule out a second primary tumor. Endoscopic ultrasound guided FNA was performed, which showed metastatic NPC. To the best of our knowledge, this is the first documented case of periportal lymph node metastasis of nasopharyngeal carcinoma.