Primary Central Nervous System Lymphoma of the Cerebellopontine Angle: Epidemiological Characteristics and Imaging Features may be Helpful for Making an Accurate Preoperative Diagnosis

Purpose Primary central nervous system lymphoma (PCNSL) of the cerebellopontine angle (CPA) is rare, thus the preoperative diagnosis is still a challenge.Methods We searched the database at our institution and performed a search of English literature in PubMed and Google Scholar. Keywords used were as follows: “primary central nervous system lymphoma”; “cerebellopontine angle”; “lymphoma”. Only cases in the English language that were located in the CPA and contained adequate clinical information pertinent to the analysis were included.Results 297 cases of pathologically confirmed PCNSLs were recorded between January 2009 and October 2020 at our institution. 6 cases were located in the CPA, accounting for 2.0% of all PCNSLs. 26 cases meeting the above criteria were found in the literature. Including ours, a total of 32 patients were analyzed. Females were more frequently affected (F/M ratio, 2.2:1). There was a preponderance of left-sided lesions in the PCNSLs of the CPA (L/R ratio, 1.5:1). On CT, 80.0% of them presented as hyperdense lesions. On T1-weighted image, 66.7% appeared isointense. While on T2-weighted image (T2WI), 68.4% appeared isointense/hypointense. After contrast administration, 86.2% presented intense homogeneous enhancement.Conclusion PCNSL of the CPA is extremely rare, accounting for 2.0% of all PCNSLs in our study. There is a preponderance of females and left-sided lesions in this disease. Contrast-enhanced magnetic resonance imaging with T2WI is very helpful in the preoperative diagnosis of the CPA PCNSL. Although rare, lymphoma should be included in the differential diagnosis of CPA lesions.