Disseminated oligodendroglial-like leptomeningeal tumor of childhood: a distinctive clinicopathologic entity

Abstract

Rare, generally pediatric oligodendroglioma-like neoplasms with extensive leptomeningeal dissemination have been interpreted variably as glial, oligodendroglial or glioneuronal. The clinicopathologic features have not been fully characterized. We studied 36 patients, 12 females and 24 males with a median age of 5 years (range 5 months-46 years). MRI demonstrated leptomeningeal enhancement, frequently with cystic or nodular T2 hyperintense lesions within the spinal cord/brain along the subpial surface. A discrete intraparenchymal lesion, usually in the spinal cord, was found in 25 (of 31) (81 %). Tumors contained oligodendroglioma-like cells with low-mitotic activity (median 0 per 10 high power fields, range 0-4), and rare ganglion/ganglioid cells in 6 cases (17 %). Tumors were mostly low-grade, with anaplastic progression in 8 (22 %). Immunohistochemistry demonstrated strong reactivity for OLIG2 (7 of 9) (78 %), and moderate/strong S100 (11 of 12) (92 %), GFAP (12 of 31) (39 %) and synaptophysin (19 of 27) (70 %). NeuN, EMA, and mutant IDH1 (R132H) protein were negative. Median MIB1 labeling index was 1.5 % (range <1-30 %). FISH (n = 13) or SNP array (n = 2) demonstrated 1p loss/intact 19q in 8 (53 %), 1p19q co-deletion in 3 (20 %), and no 1p or 19q loss in 4 (27 %). Clinical follow-up (n = 24) generally showed periods of stability or slow progression, but a subset of tumors progressed to anaplasia and behaved more aggressively. Nine patients (38 %) died 3 months-21 years after diagnosis (median total follow-up 5 years). We report a series of a neoplasm with distinct clinicopathologic and molecular features. Although most progress slowly, a significant fraction develop aggressive features.

Diffuse anaplastic leptomeningeal oligodendrogliomatosis mimicking neurosarcoidosis

“…1,6 The presence of mitoses on biopsy, as seen in our patient, predicts shorter survival. 1 Dramatic clinical and radiologic improvement has been reported in a patient with anaplastic primary leptomeningeal oligodendrogliomatosis and 1p19q codeletion who was treated with temozolomide. 6 Our patient died shortly after starting temozolomide and radiation therapy.…”

“…Although the 1p19q codeletion is associated with better overall survival for patients with intracerebral oligodendrogliomas, a similar relationship has not been observed in diffuse leptomeningeal oligodendrogliomatosis. 1 This case highlights the importance of a maintaining a high index of suspicion for leptomeningeal malignancies in patients presenting with chronic meningitis. Because the yield of biopsy in diffuse leptomeningeal oligodendrogliomatosis is low, multiple biopsies when signs progress may be needed to confirm the diagnosis.…”

“…2,6 Elevated CSF protein is common among reported cases, but CSF cytology is almost uniformly negative, as it was in this case. 1,2 This suggests that tumor cells spread centrifugally along the meninges rather than via dissemination in the CSF. 7 Patients with leptomeningeal oligodendrogliomatosis may experience periods of stability or slow progression.…”

“…7 Patients with leptomeningeal oligodendrogliomatosis may experience periods of stability or slow progression. 1 However, approximately one-third of tumors progress to anaplasia, leading to death months to years after diagnosis. 1,6 The presence of mitoses on biopsy, as seen in our patient, predicts shorter survival.…”

“…1 However, approximately one-third of tumors progress to anaplasia, leading to death months to years after diagnosis. 1,6 The presence of mitoses on biopsy, as seen in our patient, predicts shorter survival. 1 Dramatic clinical and radiologic improvement has been reported in a patient with anaplastic primary leptomeningeal oligodendrogliomatosis and 1p19q codeletion who was treated with temozolomide.…”