The Rare Primary Low Grade Papillary Adenocarcinoma of Nasopharynx: A Diagnostic Challenge and Management

Low Grade Papillary Nasopharyngeal Adenocarcinoma (LGPAC) is a very rare tumour of mucosal origin compared to a higher incidence of well differentiated keratinized/non-keratinized nasopharyngeal carcinoma. It is an epithelial tumour with glandular differentiation. Its papillary figure seen histologically, is also seen in metastatic papillary thyroid carcinoma. This has caused a significant challenge to the Pathologist to differentiate primary papillary nasopharyngeal adenocarcinoma and metastatic tumour. Thyroid Transcription Factor-1 (TTF-1) is also expressed in subsets of papillary nasopharyngeal adenocarcinoma, which is valuable as a diagnostic tool. LGPAC is a benign-like malignant neoplasm. An early diagnosis with a complete tumour removal via conventional excision or endoscopic approach has offered a good prognosis with low risk of recurrence.