Infratemporal fossa tumors: When to suspect a malignant tumor? A retrospective cohort study of 62 cases

Infratemporal fossa (ITF) tumors are rare and little is known about their general epidemiology, making it sometimes difficult for clinicians, who seldom encounter them, to distinguish between benign and malignant forms on the basis of the initial clinical and radiological work-up alone. The objectives of this retrospective study were: (i) to determine the respective prevalences of the various histologic types of ITF tumor, and (ii) to assess associations between certain clinical and radiological features and malignancy.

A single-center observational study in a university hospital included all new consecutive cases of ITF tumor treated from January 2000 to December 2016. Histologic type, demographics, clinical presentation and imaging findings were analyzed.

In total, 62 patients were included. 74% of tumors were benign (n=46) and 26% malignant. Juvenile nasopharyngeal angiofibroma, adenoid cystic carcinoma and schwannoma were the most frequent histologic types, accounting for 47%, 16% and 10% of cases, respectively. The only clinical or imaging signs significantly associated with malignancy were trismus, facial pain, facial hypoesthesia and neural invasion on magnetic resonance imaging (all P-values<0.05).

This study provides general epidemiological data on ITF tumors, and identified several clinical and radiologic signs to help clinicians suspect malignancy.