TY - JOUR
T1 - Diffuse leptomeningeal neuroepithelial tumor
T2 - 9 pediatric cases with chromosome 1p/19q deletion status and IDH1 (R132H) immunohistochemistry
AU - Schniederjan, Matthew J.
AU - Alghamdi, Sarah
AU - Castellano-Sanchez, Amilcar
AU - Mazewski, Claire
AU - Brahma, Barunashish
AU - Brat, Daniel J.
AU - Brathwaite, Carole D.
AU - Janss, Anna J.
PY - 2013/5
Y1 - 2013/5
N2 - Leptomeningeal dissemination in children is typical of high-grade, and occasionally low-grade, neoplasms. Rare cases of widely disseminated oligodendroglia-like leptomeningeal tumors, sometimes with associated spinal cord lesions, have been described that respond to treatment and follow an indolent course. Whether these lesions represent an established tumor category or are a unique entity remains to be established. We present 9 pediatric cases of such diffuse leptomeningeal neuroepithelial tumors (DLNT), 8 with assessment of 2 common genetic alterations seen in oligodendrogliomas, 1p and 19q chromosomal deletions and isocitrate dehydrogenase-1 (IDH1) R132H mutations. Four patients were male and 5 female, with a mean age at presentation of 4 years (range, 2 to 7 y). All presented with signs of increased intracranial pressure and diffuse contrast enhancement of the leptomeninges by magnetic resonance imaging. Three had a cervical or upper thoracic spinal cord tumor, and another had a small cerebellar lesion. Leptomeningeal biopsies showed a thickened and fibrotic arachnoid infiltrated by monotonous cells with round nuclei and prominent perinuclear clearing. All cases were strongly immunoreactive for S100 protein, and most showed faint granular synaptophysin reactivity. Six of 8 cases showed deletions of chromosome arm 1p by fluorescence in situ hybridization, 2 of which also had loss of 19q. None of the lesions reacted with IDH1-R132H antibodies. Although the clinicopathologic features show overlap of these DLNT lesions with oligodendroglioma and extraventricular neurocytoma, they do not exactly match either one, suggesting that DLNTs are a distinct tumor entity.
AB - Leptomeningeal dissemination in children is typical of high-grade, and occasionally low-grade, neoplasms. Rare cases of widely disseminated oligodendroglia-like leptomeningeal tumors, sometimes with associated spinal cord lesions, have been described that respond to treatment and follow an indolent course. Whether these lesions represent an established tumor category or are a unique entity remains to be established. We present 9 pediatric cases of such diffuse leptomeningeal neuroepithelial tumors (DLNT), 8 with assessment of 2 common genetic alterations seen in oligodendrogliomas, 1p and 19q chromosomal deletions and isocitrate dehydrogenase-1 (IDH1) R132H mutations. Four patients were male and 5 female, with a mean age at presentation of 4 years (range, 2 to 7 y). All presented with signs of increased intracranial pressure and diffuse contrast enhancement of the leptomeninges by magnetic resonance imaging. Three had a cervical or upper thoracic spinal cord tumor, and another had a small cerebellar lesion. Leptomeningeal biopsies showed a thickened and fibrotic arachnoid infiltrated by monotonous cells with round nuclei and prominent perinuclear clearing. All cases were strongly immunoreactive for S100 protein, and most showed faint granular synaptophysin reactivity. Six of 8 cases showed deletions of chromosome arm 1p by fluorescence in situ hybridization, 2 of which also had loss of 19q. None of the lesions reacted with IDH1-R132H antibodies. Although the clinicopathologic features show overlap of these DLNT lesions with oligodendroglioma and extraventricular neurocytoma, they do not exactly match either one, suggesting that DLNTs are a distinct tumor entity.
KW - 1p
KW - 1p19q
KW - disseminated
KW - glioneuronal
KW - leptomeninges
KW - neurocytoma
KW - neuroepithelial
KW - oligodendroglioma
KW - pediatric
KW - spinal cord
UR - http://www.scopus.com/inward/record.url?scp=84876527927&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84876527927&partnerID=8YFLogxK
U2 - 10.1097/PAS.0b013e31827bf4cc
DO - 10.1097/PAS.0b013e31827bf4cc
M3 - Article
C2 - 23588371
AN - SCOPUS:84876527927
SN - 0147-5185
VL - 37
SP - 763
EP - 771
JO - American Journal of Surgical Pathology
JF - American Journal of Surgical Pathology
IS - 5
ER -