Leptomeningeal dissemination at diagnosis of pediatric low-grade neuroepithelial tumors

Abstract

The goal of this study was to describe the demographic, histologic, and prognostic features of children with low-grade neuroepithelial tumors (LGN) of the CNS presenting with leptomeningeal metastases (LM) at diagnosis. We identified 528 newly diagnosed LGN children, 13 (3%) of whom had LM at diagnosis. LM was defined by neuroimaging, clinical evidence, and/or biopsy. The charts were reviewed and patients contacted to validate the demographic data, treatment, and clinical status. The distribution of LM patients by primary tumor site was diencephalon, 5; cerebrum, 2; spinal cord, 3; brainstem, 2; and cerebellum, 1. Six of 8 patients with LM had durable objective responses to chemotherapy. The 5-year progression-free survival of patients with LM at diagnosis was 17%, compared to 85% (95% CI, 80%-91%) for those with localized LGN who had a gross total resection and 51% (95% CI, 44%-52%) for those with localized LGN who had less aggressive surgery ( P < 0.0001). Only 1 of these 13 LM patients died. The 5-year overall survival of the localized LGN group with a gross total resection was 97% (95% CI, 92%-99.9%), and that of the localized LGN group with less aggressive surgery was 88% (95% CI, 84%-95%) ( P = 0.004). The 3% frequency of LM at diagnosis is likely an underestimate since patients with newly diagnosed LGN were not routinely staged. We suggest that staging be considered in the following circumstances: diencephalic primary site, unexplained hydrocephalus, clinical features suggestive of LM, and before adjuvant therapy is initiated. The prognosis for children with LM at diagnosis is favorable, and its identification alters therapeutic strategies.

Use of T2 signal intensity of cerebellar neoplasms in pediatric patients to guide preoperative staging of the neuraxis

“…27 While the risk of LD with cerebellar JPAs is extremely small, it is not zero. 9 Over the past 30 years, there have been 4 case reports 3,19,30,36 of leptomeningeal spread of cerebellar JPAs found at/near the time of initial diagnosis, all of which included LD to the spine. These reports are summarized in Table 3.…”

“…In contrast to these tumors, the incidence of LD at presentation in patients with JPAs is extremely low. Specifically, 4 known cases 3,19,30,36 of LD of pediatric cerebellar JPAs found at presentation have been reported in the literature over the past 30 years (Table 2). Information regarding the incidence of LD of other, less common histopathological entities comprising the remaining approximately 15% of pediatric cerebellar neoplasms is sparse.…”

Pediatric low-grade gliomas: How modern biology reshapes the clinical field

“…Leptomeningeal dissemination is reported in approximately 3–5% of children at presentation, especially in the setting of spinal cord or diencephalic/hypothalamic lesions 72–74 , and may be associated with inferior overall survival compared to those who present with localized disease 75–77 .…”

Leptomeningeal metastases

“…Other neuroepithelial primary brain tumors, including low-grade gliomas, frequently progress to LM (14%) [7,17,18•]. A retrospective study of low-grade pediatric gliomas found 24 of 528 patients had LM, 13 of whom had LM at diagnosis [19].…”