An interesting case of a schneiderian carcinoma

Abstract

We present a case report of an unusual tumour, a Schneiderian carcinoma [also known as a cylindrical cell carcinoma, transitional (cell) carcinoma, Ringertz carcinoma or respiratory epithelial carcinoma] which is classified by the WHO as a sinonasal non-keratinising squamous cell carcinoma (SCC). The patient is a 72-year-old lady who was initially diagnosed with poorly-differentiated SCC of the left nasopharynx in 2003. She has had surprisingly slow disease progression with late recurrences and cervical nodal metastases without systemic dissemination. The tumour has been diagnosed as a poorly-differentiated, non-keratinising SCC (positive CK5/6, p63, p40, and negative for neuroendocrine, melanocytic and lymphoid markers). However, morphologically this tumour is unusual, as it displays no features of keratinisation and has a distinctive ribbon-like architecture, resembling urothelium, and a striking abundance of admixed neutrophils including microabscesses (identical to Schneiderian papilloma). Recent literature has suggested that Schneiderian carcinomas, although classified under the umbrella of ‘sinonasal SCC’, display a distinctive morphology, clinical course and appear to have a strong aetiological relationship with high-risk human papilloma virus. We highlight the importance of recognising these tumours and distinguishing them from differential diagnoses such as Schneiderian papillomas and typical SCC.