Читать книгу Anterior Skull Base Tumors - Группа авторов - Страница 21

Squamous carcinoma typically occurs in elderly individuals in their 6th and 7th decades with a tendency for male gender (M:F 2:1) [1–3]. The most common sites are the maxillary sinus, nasal cavity, and ethmoid, frontal, and sphenoid sinus. Grossly, squamous carcinomas are typical ulcerated and indurate with exophytic features; sinus tumours are bulky and composed of friable light tan tumour tissues [4]. Histologically, tumours typically display squamous differentiation and are graded as well, moderately, or poorly differentiated. Tumours originating from the nasal cavity are generally well differentiated. Tumours of the paranasal sinuses and skull base are commonly non-keratinising carcinomas of intermediate to poor differentiation. Poorly differentiated carcinomas are also called Schneiderian carcinoma and may originate from preexisting inverted papillomas [5, 6]. Rarely, tumours may exhibit spindle cell features and mimic sarcoma or spindle cell melanoma.