Liponeurocytoma of the Cerebellopontine Angle

Liponeurocytoma: Rare Neoplasm of the Central Nervous System

In this case report, we characterize an instance of diagnosis, treatment, characteristics, and outcomes of a patient with a liponeurocytoma, a rare WHO grade II brain tumor first described in 1978. This tumor has been described with a wide array of radiographic, microscopic, and histologic features, and there remains no consensus regarding the role of radiation therapy. Most patients have favorable outcomes after surgical resection. Here we present the case of a 46-year-old female who underwent suboccipital craniectomy for resection of a cerebellar mass, which was diagnosed as liponeurocytoma on final pathology. The patient experienced resolution of symptoms and is neurologically intact two years after resection of the tumor.

Cerebellar liponeurocytoma: clinical, histopathological and molecular features of a series of three cases, including one recurrent tumor

Cerebellar liponeurocytoma (CL) is an unusual tumor, histologically composed of a mixture of small to medium-sized, rounded neurocytic cells and a variable lipomatous component. Although CL was originally considered as a subtype of medulloblastoma, subsequent molecular studies demonstrated that this tumor was a distinct entity, exhibiting the tumor protein p53 gene (TP53) missense mutations in 20% of cases, chromosome 17 deletion, and the absence of mutations in the adenomatous polyposis coli gene (APC), the protein patched homolog gene (PTCH), the kinase insert domain receptor gene (KDR), and the β-catenin gene (CTNNB). Apart from these molecular features, little is known about the pathogenesis and the genetic landscape of CL to date. In order to characterize the mutational landscape of CL and identify alterations that are driving tumorigenesis, we report a series of three cases, including one recurrent tumor, analysed by next-generation sequencing (NGS), which identified a total of 22 variants, of which four were missense mutations, nine were synonymous variants, and nine were located on intronic regions. In particular, DNA sequencing identified missense mutations in APC, KDR, and TP53 that could be implicated in promoting tumor progression and angiogenesis of CL. Furthermore, the NGS analysis revealed that recurrent CL did not have additional genetic changes compared with the primary tumor. Moreover, the high frequencies of detected mutations suggested that the identified alterations are germline variants. Indeed, an additional NGS on the genomic DNA obtained from one of the three patients confirmed the presence of the variants in the germline DNA. In conclusion, the obtained data support the hypothesis that CL is a distinct pathological entity that does not show specific somatic alterations driving tumorigenesis.

Surgical management and clinical outcomes of cerebellar liponeurocytomas-a report of seven cases and a pooled analysis of individual patient data

Cerebellar liponeurocytomas (CLPNs) are very rare, with very few studies on this disease. Their treatment protocol also remains unclear. To better understand the disease, we reviewed the clinical features and outcomes, and proposed a treatment protocol based on previously reported cases as well as cases from our institute. The clinical data were obtained from seven patients with pathologically confirmed CLPNs, who underwent surgical treatment at our institute between November 2011 and June 2021. We also reviewed the relevant literature and 75 patients with CLPNs were identified between September 1993 and June 2021. Risk factors for progression-free survival (PFS) were evaluated in the pooled cohort. Our cohort included four males and three females, with a mean age of 43.9 ± 14.5 years (range: 29-64 years). CLPNs were located in the lateral ventricle in three cases and in the cerebellum in four cases. All seven cases achieved gross total resection (GTR) and radiotherapy was administered to two cases. After a mean follow-up of 44.9 ± 44.4 months, all patients remained well, with no recurrence or death. Among the 75 patients reported in the literature, 35 were males and 40 were females, with a mean age of 46.2 ± 13.6 years (range: 6-77 years). Biopsy, GTR, and non-GTR were achieved in one (1.3%), 50 (66.7%), and 24 (32%) patients, respectively. Radiotherapy was administered to 16 cases and chemotherapy was administered to only one case. After a mean follow-up of 47.5 ± 51.5 months, three patients died and tumor recurrence occurred in 17 patients. Multivariate Cox analysis revealed that non-GTR predicted a poor PFS (p = 0.020), and postoperative radiotherapy could not prolong PFS (p = 0.708). Kaplan-Meier analysis also showed that GTR was significantly associated with longer PFS (p = 0.008), and postoperative radiotherapy could not prolong PFS (p = 0.707). PFS rates at 1, 5, 10 years were 92.7%, 78.0%, 23.8% respectively. CLPNs are very rare brain tumors. Although they have favorable clinical prognosis, the recurrence is relatively high. GTR should be the first choice for treatment and close follow-up is necessary. Postoperative radiotherapy could not improve PFS in this study. A larger cohort is needed to verify our findings.