Clinical, Radiological, Pathological Features and Seizure Outcome With Surgical Management of Polymorphous Low-Grade Neuroepithelial Tumor of the Young Associated With Epilepsy

Abstract

ObjectivePolymorphous low-grade neuroepithelial tumor of the young (PLNTY) is a novel distinct epileptogenic neoplasm, and its clinical, imaging, histopathological, and molecular features were already known in the existing literature. We aimed to analyze the surgical management of PLNTY combined with these known characteristics.MethodsEight patients underwent surgical treatment in our center between December 2017 and December 2020, and the postoperative pathology was diagnosed as PLNTY. Their clinical data, imaging, pathological, molecular characteristics, and seizure outcome were retrospectively analyzed. Follow-up evaluations and a literature review were performed.ResultsThe 8 patients included 1 woman and 7 men, aged between 5 and 51 years old (mean = 31.6, median = 29). The preoperative symptoms of all 8 cases were seizures. Four tumors were situated in the temporal lobes, and one of the four extratemporal tumors was in the occipital lobe and three were in the frontal lobe. Enlarged and gross total resections were performed in 2 cases and the other 6 cases, respectively. All cases exhibited intense labeling of CD34, and absence of 1p/19q codeletion and IDH1 or IDH2 mutation. B-Raf proto-oncogene (BRAF) V600E mutation was presented in 4 (66.7%) of 6 detected cases. The postoperative seizure outcome of Engel class I was achieved in 6 cases (75%).ConclusionPLNTY represents distinctive histologic, immunophenotypic and biomolecular features, and has high epileptogenicity. Early surgical intervention and enlarged resection of PLNTY associated with epilepsy will help to improve the postoperative seizure-free rate.

Pediatric and elderly polymorphous low‐grade neuroepithelial tumor of the young: Typical and unusual case reports and literature review

“…Generally, a glioneuronal tumor, one of the epileptic foci, is located in the cortex, especially the temporal lobe 5 . To date, at least 68 cases of PLNTY had been reported (Table 1), 2,6–23 and eight cases, including ours, were over 40 years old 7,9,15,18,24 . “Pediatric‐type” tumors, including PLNTY, occur mainly in childhood but do appear in adults, and vice versa 25 .…”

“…2 A few studies have investigated p53 abnormality in PLNTY. 2,6,10,11,15,22,24 Postoperative seizure and/or MRI abnormalities were more frequent, but not statistically significant, in cases with p53 overexpression than in those without p53 abnormalities (2/5 (40.0%) vs. 2/13 (15.4%); P = 0.533). In one case of PLNTY with malignant transformation, TP53 mutation was observed.…”

“…The association between subcortical PLNTY and non‐epileptic onset requires further investigation 2 . A few studies have investigated p53 abnormality in PLNTY 2,6,10,11,15,22,24 . Postoperative seizure and/or MRI abnormalities were more frequent, but not statistically significant, in cases with p53 overexpression than in those without p53 abnormalities (2/5 (40.0%) vs. 2/13 (15.4%); P = 0.533).…”

“…5 To date, at least 68 cases of PLNTY had been reported (Table 1), 2,[6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] and eight cases, including ours, were over 40 years old. 7,9,15,18,24 "Pediatric-type" tumors, including PLNTY, occur mainly in childhood but do appear in adults, and vice versa. 25 Although the morphological difference was not evident (Table 1), non-epileptic onset tends to occur more often in patients over 18 years old (P = 0.222).…”

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

“…In contrast, other cases tend to have a completely well-defined borderline. The infiltrated growth patterns may explain the unclear boundary with normal brain tissue in radiology [ 19 ].…”