A Case of Craniocervical Junction Arteriovenous Fistulas with a Brainstem Mass Lesion on Imaging: Case Report and Literature Review.

Intracranial mass lesions occur within the cranial cavity, and their etiology is diverse. Although tumors and hemorrhagic diseases are the common causes, some rarer etiologies, such as vascular malformations, might also present with intracranial mass lesion manifestations. Such lesions are easily misdiagnosed due to the lack of manifestations of the primary disease. The treatment involves a detailed examination and differential diagnosis of the etiology and clinical manifestations. On 26 October 2022, a patient with craniocervical junction arteriovenous fistulas (CCJAVFs) was admitted to Nanjing Drum Tower Hospital. Imaging examinations showed a brainstem mass lesion, and the patient was initially diagnosed with a brainstem tumor. After a thorough preoperative discussion and a digital subtraction angiography (DSA) examination, the patient was diagnosed with CCJAVF. The patient was cured using interventional treatment, and an invasive craniotomy was not required. During diagnosis and treatment, the cause of the disease might not be apparent. Thus, a comprehensive preoperative examination is very important, and physicians need to conduct the diagnosis and differential diagnosis of the etiology based on the examination to administer precise treatment and reduce unnecessary operations.