Low-Grade Papillary Schneiderian Carcinoma; rare or under-recognised?

• Main Authors: Andrew Williamson, Rishi Sharma, Lorna Cooper, Gerald McGarry
• Format: Article
• Language: English
• Published: Elsevier 2019-06-01
• Series: Otolaryngology Case Reports
• Online Access: http://www.sciencedirect.com/science/article/pii/S2468548818301917

Inverting papillomas (IP) are benign sinonasal tumours that can undergo transformation to squamous cell carcinoma (SCC). Low-Grade Papillary Schneiderian Carcinoma (LGPSC) is a unique malignancy that shares similar morphology to IP, but demonstrates invasive patterns different from SCC.Here we report the case of a patient who underwent excision of a unilateral sinonasal tumour with histopathology demonstrating bland cells and non-invasive “pushing” borders. The tumour recurred rapidly with extensive local invasion, however, further excisions continued to show non-malignant morphology, leading to diagnosis of LGPSC. The patient required radical maxillectomy to achieve complete disease clearance.LGPSC is rare with only two previous descriptions in the literature. LGPSC appears similar to IP, but has “pushing” borders and a propensity for rapid local recurrence. It is likely some existing cases of aggressive IP are LGPSC and we therefore advise MDT discussion for all unusual cases of IP. Keywords: Sinonasal malignancy, Inverted papilloma