Epstein-Barr Virus RNA Detection and Glandular Differentiation in Nasopharyngeal Carcinoma

Abstract

Most tumors arising in the nasopharynx are either squamous cell carcinoma or so-called undifferentiated carcinoma of the nasopharyngeal type. Primary adenocarcinomas of the nasopharynx are rare, and glandular differentiation in undifferentiated carcinoma of the nasopharyngeal type has not been reported to date. We report 2 cases of undifferentiated carcinoma of the nasopharyngeal type that show distinct glandular differentiation by light microscopy, histochemistry, immunohistochemistry, and ultrastructure. Both tumors showed equal positivity for Epstein-Barr virus latent membrane protein and in situ hybridization for Epstein-Barr virus genome in the undifferentiated areas of the tumor and those featuring glandular differentiation.

Non-Keratinizing Nasopharyngeal Carcinoma with Adenomatous Differentiation

“…Very rarely, a reticular myxoid pattern may be encountered [2]. To the best of my knowledge, there has only been one previous report on two patients with NK-NPC showing adenomatous, "glandular" differentiation [3]. This study included two male, Caucasian patients-one 58 yearsold, the other 56.…”

“…Very rarely, NPC may display a cord-like, reticular arrangement of tumor cells associated with significant myxoid substances in the stroma [2]. Extremely rarely NPC may exhibit adenomatous differentiation [3]. This report presents a case of NPC with a component of the tumor where adenomatous structures were formed.…”

A rare case of intracytoplasmic mucin‐rich nasopharyngeal carcinoma

“…In addition to these classical morphologies, NPCs may have various uncommon histological patterns 2 . Some studies report a salivary gland type and adenocarcinoma‐like NPC as uncommon variants 3–5 . However, the morphological spectrum of NPC remains to be understood.…”

“…2 Some studies report a salivary gland type and adenocarcinoma-like NPC as uncommon variants. [3][4][5] However, the morphological spectrum of NPC remains to be understood. NPC often presents with cervical lymphadenopathy, preceding the identification of the primary tumor.…”