Subacute necrotizing sialadenitis: a clinicopathological study

Objective: To report cases of extra-palatal subacute necrotizing sialadenitis (SANS), an uncommon condition that usually affects palatal minor salivary glands, and to characterize the etiopathogenesis, clinical features, and histology of this lesion. Study design: Retrospective reviews of records for patients with SANS diagnosed between 1999 and 2005; only cases with complete clinical history and histology were included in the study. Results: Five cases (3 women, 2 men) were identified. The majority of patients presented with painful 1.0 to 1.5cm swellings, with sudden and rapid increase in size. Two cases occurred in the buccal mucosa, 2 on the ventral surface of tongue, and 1 on the upper lip. Histology showed acinar necrosis surrounded by a dense polymorphous inflammatory infiltrate with focal exuberant tissue eosinophilia. Ductal atrophy was seen with minimal squamous metaplasia. In all the cases, healing occurred without any further treatment in 3 weeks. No recurrence was observed. Conclusion: SANS is an uncommon, inflammatory condition of unknown etiology affecting minor salivary glands. SANS appears to be a self-limiting process that has distinct characteristic clinical and histologic features. Nevertheless, SANS shares some of the histologic features of early necrotizing sialometaplasia (NS), suggesting a possible relationship between the 2 conditions. Additional reporting of SANS would be helpful in better defining the condition and its delineation from NS.