Otolaryngologie : accès libre

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Basaloid Squamous Cell Carcinoma in Nasal Cavity with Neural-Type Rosettes: A Diagnostic Challenge.

Dr. Juan Carlos López Duque

BSCC is a well defined variant of Squamous Cell Carcinoma (SCC) with an aggressive behaviour. It grows in the upper respiratory tract mostly, but it has been seldom reported to occur in the sinonasal tract; mucous of nasal cavity and paranasal sinuses. We report here the case of a male with a right nasal cavity tumour with obstruction and some nasal bleeding. The image study (CT and MRI) showed a polypoid mass that infiltrates the lateral wall of the sinus. The endoscopic biopsy showed an infiltrative basaloid tumour with areas of neural-type rosettes that was a diagnostic challenge even using a wide IHQ panel, given that there wasn’t squamous component. The pathological examination of the surgical resection showed a typical morphology of the BSCC and a strong p63 and p16 reactivity. The molecular study found several high grade HPV phenotypes. There is only a previous report (two cases) with neural-type rosettes and to the best of our knowledge, our case is the sole HPV related found, in this site. Keywords: Basaloid squamous cell carcinoma; Nasal cavity; Neuraltype rosettes; p16; HPV Introduction The Basaloid Squamous Cell Carcinoma (BSCC) is an aggressive high grade variant of squamous carcinoma mainly seated in larynx, hypopharynx and base of tongue [1]. A few cases have been reported in the sinonasal tract [2-7] and rarely with a growth pattern of neural type rosettes. The correct identification of this tumour in small endoscopic biopsy is a diagnostic challenge even with the proposed immunohistochemical procedure [5,9,10], because the squamous component is scan and difficult to identify in the tumoral tissue. We report a case of BSCC with true neuraltype rosettes growing in the right nasal fossa with extensions that go from the middle turbinate to the choanae. In this area the differential diagnosis include, high grade basaloid tumours with glandular adenoid pattern such as: small cell neuroendocrine carcinoma, olfactory neuroblastoma (grade 3 of Hyams), adenocarcinoma of intestinal-type and non intestinal-type and salivary gland type Adenoid Cystic Carcinoma (ACC) of solid pattern..