Leptomeningeal dissemination of low-grade neuroepithelial CNS tumors in adults: a 15-year experience.

BACKGROUND

Leptomeningeal dissemination (LD) in adults is an exceedingly rare complication of low-grade neuroepithelial CNS tumors (LGNs). We aimed to determine relative incidence, clinical presentation, and predictors of outcome.

METHODS

We searched the quality control database of the Section of Neuro-Oncology, Yale Cancer Center, for patients with LGN (WHO grade I/II) seen between 2002 and 2017. For cases complicated by LD, we recorded demographics, clinical signs, histopathological diagnosis, and imaging findings. A comprehensive literature review was performed.

RESULTS

Eleven consecutive patients with LD were identified, representing 2.3% of individuals with LGN seen at our institution between 2002 and 2017 (n = 475). Ependymoma was the predominant histological entity. Mean time interval from diagnosis of LGN to LD was 38.6 ± 10 months. Symptoms were mostly attributed to communicating hydrocephalus. Tumor deposits of LD were either nodular or linear with variable enhancement (nonenhancing lesions in 4 of 11 patients). Localized (surgery, radiosurgery, involved-field, or craniospinal radiation therapy) or systemic treatments (chemotherapy) were provided. All patients progressed radiographically. Median overall survival after LD was 102 months. Survival was prolonged when a combination of localized and systemic therapies was administered (188.5 vs 25.5 months; = .03). Demographics and tumor spectrum reported in the literature were similar to our cohort.

CONCLUSIONS

LD is a rare complication of LGNs. A high level of suspicion is required for timely diagnosis as early symptoms are nonspecific and commonly do not occur until years after initial tumor diagnosis. Repeated aggressive treatment appears to be beneficial in improving survival.