Amyloid and hyaline globules in undifferentiated nasopharyngeal carcinoma.

We characterize the clinicopathological features of two patients (one 38 year old woman and one 42 year old man, both of Chinese ethnicity) with Epstein Barr Virus positive non-keratinizing nasopharyngeal carcinoma from an endemic region with prominent presence of amyloid and one case with both amyloid and abundant intracytoplasmic hyaline globules. The amyloid material was positive for Congo red and showed apple green birefringence when examined under polarized light. The amyloid was immunoreactive for cytokeratins and was located both intra- and extracellularly. Frequently the amyloid had a light microscopical spherical appearance and displayed peripheral radiating fibrils from a central homogenous core. One of the patients had a unique presentation of nasopharyngeal carcinoma with perceived hemoptysis and coughing up two pieces of tumor tissue. In reality, the nasopharyngeal tumor was polypoid and the two fragments were pinched of from the main tumor mass.