Cranial Rhabdomyosarcoma Masquerading as Infectious Mastoiditis: Case Report and Literature Review.

Background: Rhabdomyosarcoma originating in the mastoid is rare and may be misdiagnosed as an infectious mastoiditis due to overlapping clinical and imaging features. We aimed to identify distinguishing characteristics to facilitate earlier diagnosis and treatment.

Method: Here we describe a case report and a systematic review of 23 reports describing previous cases of mastoid rhabdomyosarcoma. We compare these patients to a systematic review of patients with infectious mastoiditis and identify distinguishing clinical features.

Results: A total of 43 patients with rhabdomyosarcoma of the mastoid were identified and compared with patients with mastoiditis. Rhabdomyosarcoma patients were more likely to present with a mass (86%) or cranial nerve dysfunction (83.7%), while mastoiditis patients were more likely to have fever (72.4%), pain (48.2%), and present at a younger age (4.4 vs. 6.1 years). The average lifespan with rhabdomyosarcoma of the mastoid was 7.1 months after diagnosis, with 41.7% of patients alive at the time of report.

Conclusions: Based on abstracted and aggregated information, we identified unique features observed more frequently in each of rhabdomyosarcoma and mastoiditis. These predictive features allow for the differentiation of each diagnosis and avoid the delay of proper treatment.