Prognostic Significance of Granuloma and Amyloid Deposition in Nasopharyngeal Carcinoma

The significance of granuloma and amyloid deposition in primary nasopharyngeal carcinoma (NPC) has yet to be investigated. This study aimed to evaluate their clinicopathologic associations. The histopathologic findings of 747 consecutive patients with primary NPC were retrospectively reviewed between January 2001 and December 2015. The presence of granulomas and amyloid deposits was observed in 68 (9.1%) and 62 (8.3%) patients, respectively. Granulomas were significantly associated with lower T classification, N classification, and overall TNM stage (p = 0.014, p = 0.006, and p = 0.001, respectively). Their presence was an independent predictor of overall survival (p = 0.033), disease-free survival (p = 0.034), and recurrence-free survival (p = 0.040). Conversely, amyloid deposition was not a predictor in any survival analyses. The present study demonstrated the prevalence of granuloma and amyloid deposition in the largest single institution cohort of primary NPC patients so far. Our results provide evidence that granulomas are significantly associated with better prognosis and treatment outcome. Further studies are needed to elucidate the mechanism of action of granuloma formation on the anti-tumor immunity of NPC.