Radiological and surgical aspects of polymorphous low-grade neuroepithelial tumor of the young (PLNTY)

Abstract

Background Polymorphous low-grade neuroepithelial tumor of the young (PLNTY) is a low-grade epilepsy-associated tumor recently introduced in WHO 2021 classification. Since it has been recognized as an independent nosological entity, PLNTY has been mainly studied from a genetic and molecular perspective, not recognizing unique characteristic clinical and radiological features. Methods A systematic literature research has been conducted aiming to identify all relevant studies about the radiological, clinical and surgical features of PLNTY. We described a representative case of a 45-year-old man treated with awake-surgery with confirmed diagnosis of PLNTY, reporting the radiological and surgical characteristics through imaging and intra-operative video. We performed a statistical meta-analysis attempting to assess the presence of relationships between surgical and radiologic tumor characteristics and clinical outcome and type of surgery. Results A total of 16 studies were included in the systematic review. The final cohort was composed of 51 patients. Extent of resection (EOR) and outcome are not significantly associated with the different genetic profiling (p = 1), the presence of cystic intralesional component, calcification (p = 0.85), contrast-enhancing and lesion boundaries (p = 0.82). No significant correlation there is between EOR and remission or better control of epilepsy-related symptoms (p = 0.38). The contrast enhancement in the tumor is significantly associated with recurrence or poor control of epileptic symptoms (p = 0.07). Conclusions In PLNTYs, contrast enhancement seems to impact prognosis, recurrence, and seizure control much more than radiological features, genetic features and type of resection of the tumor.

Advances in diffuse glial tumors diagnosis

“…8 PLNTY is marked by genetic alterations in the MAPK pathway and features a V-Raf murine sarcoma viral oncogene homolog B1(BRAF) V600E gene mutation in 48% of cases; fibroblast growth factor receptors (FGFR) gene fusions may also be present. 9 Angiocentric glioma invariably displays MYB alterations. 2 High-grade DMGs are typified by their midline location and H3-K27 alterations, whereas DHGs are infiltrative gliomas involving the cerebral hemispheres, marked by H3-G34 mutations.…”

“…Polymorphous Low-grade Neuroepithelial Tumor of the Young (PLNTY) typically presents, in the context of epilepsy, as a well-circumscribed lesions, mainly located in the posterior inferior temporal lobe, and frequently shows dense calcification and cystic components. 9 The prominent calcification is a distinct feature, although one can also account for ganglioglioma in differential diagnosis. Angiocentric gliomas often display ill-defined margins and lack enhancement.…”

“…8 PLNTY is marked by genetic alterations in the MAPK pathway and features a V-Raf murine sarcoma viral oncogene homolog B1(BRAF) V600E gene mutation in ∼48% of cases; fibroblast growth factor receptors (FGFR) gene fusions may also be present. 9 Angiocentric glioma invariably displays MYB alterations. 2…”

Systematic review and cumulative analysis of clinical properties of BRAF V600E mutations in PLNTY histological samples

“…The most comprehensive such study to date, conducted by Armocida et al, reviewed 51 cases in the literature and found a signi cant association between contrast enhancement and poorer seizure outcomes following surgery, but identi ed no other associations between imaging characteristics, demographic information, driver mutation, and outcomes. [9] As the BRAF V600E mutation is the most common PLNTY driver mutation identi ed in the literature, we sought to further characterize the clinical features associated with this PLNTY subtype and with clinical outcomes.…”

“…Kurokawa et al was excluded for not including individual patient data[12]. A total of 23 studies were included, and an additional 3 were identi ed by reviewing the references of these articles[1]-[9],[13]-[29]. All nine cases from Johnson et al were republished in Ida et al, therefore the data from these studies was merged[2], [8].…”