Delayed diagnosis of sinonasal lymphoma due to bilateral manifestation.

The objective of this study is to analyze the presenting symptoms, the time to correct diagnosis and outcome of a European patient cohort with sinonasal lymphoma focusing on unilateral vs. bilateral sinonasal involvement. In a retrospective setting in a European tertiary referral center, eleven patients (9 males, 2 females) with sinonasal lymphoma diagnosed between 2002 and 2015 were identified and divided into a unilateral and bilateral group according to their CT finding. Clinical findings on first presentation, the presence of B symptoms, the radiologic findings, overall survival and disease-specific survival were assessed. 55 % of the patients suffered from bilateral manifestation, which was associated with a delayed diagnosis (10 vs. 1.5 months, p < 0.05). B symptoms (67 vs. 0 %) and death of disease (50 vs. 0 %) were observed only in the bilateral group. Nasal NK/T-cell lymphoma was the most frequent diagnosis, followed by diffuse large B-cell lymphoma. Bilateral mucosal manifestation with B symptoms was shown to be common within the rare entity of sinonasal lymphomas and patients with bilateral sinonasal manifestation are at risk for a delayed diagnosis with worse outcome.