Clinical Images
Rosette-Forming Glioneuronal Tumor of Spinal Cord Adrien Collin1, Homa Adle-Biassette2, Augustin Lecler1
Key words MRI - RGNT - Rosette-forming glioneuronal tumor - Spinal - Tumor -
Abbreviations and Acronyms RGNT: Rosette-forming glioneuronal tumor From the Departments of 1Radiology, Rothschild Ophthalmological Foundation, and 2Pathology, Lariboisière Hospital, Paris Diderot, Paris-Cité-Sorbonne University, Paris, France To whom correspondence should be addressed: Adrien Collin, M.D. [E-mail:
[email protected]] Citation: World Neurosurg. (2018) 119:242-243. https://doi.org/10.1016/j.wneu.2018.08.035 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2018 Elsevier Inc. All rights reserved.
Rosette-forming glioneuronal tumor has recently been included in the World Health Organization classification as a low-grade tumor. It usually occurs in young adults, arising from the fourth ventricular region. The authors describe a rare case of rosette-forming glioneuronal tumor arising from the spinal cord with cerebrospinal fluid dissemination. Magnetic resonance imaging showed a cervical spinal cord tumor, which could be easily misdiagnosed as ependyma or astrocytoma. Surgical total resection was performed, and histopathologic examination made the diagnosis, showing a biphasic neurocytic and glial tumor with neurocytic rosettes. Six months after surgery, the patient had fully recovered.
A 40-year-old female presented with headaches, decreased visual acuity related to bilateral papillary edema, subacute lumbar pain, slight motor deficiency of the lower limbs (4/5 muscle strength grading), and hypopalesthesia of the right lower limb. Magnetic resonance imaging
Figure 1. Spinal cord magnetic resonance imaging (MRI). (A) Sagittal T2-weighted, (B) precontrast, and (C) postcontrast with fat saturation T1-weighted MRI showing a heterogeneous enhancing cervical spinal cord tumor (black arrow), leptomeningitis (arrows), and posterior epiduritis
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showed a cervical spinal cord tumor (Figure 1AeC) with leptomeningitis spreading to the posterior fossa. Median laminectomy was performed, and the tumor was macroscopically totally resected. Histopathologic examination revealed a biphasic neurocytic and glial
(arrowheads). Sagittal postcontrast T1-weighted follow-up MRI (D) performed at 6 months showed small tumor remnant (black arrow) with persistent leptomeningitis (arrows) and posterior epiduritis (arrowheads).
WORLD NEUROSURGERY, https://doi.org/10.1016/j.wneu.2018.08.035
CLINICAL IMAGES ADRIEN COLLIN ET AL.
RGNT OF SPINAL CORD
dissemination is exceedingly rare.3 Cerebrospinal fluid dissemination is commonly seen with higher-grade tumors, but RGNT should be an exception: It has been reported for the first time in 2 patients of a recent series4 (including 7 RGNT patients). Because RGNTs are rare, the imaging findings of these tumors are yet to be elucidated. Complete surgical removal, when feasible, is the treatment of choice. Radiotherapy should be taken as an adjuvant treatment for progressive or disseminated diseases and recurrent ones. REFERENCES 1. Louis DN, Ohgaki H, Wiestler OD, Cavenee WK, Burger PC, et al. The 2007 WHO classification of tumours of the central nervous system. Acta Neuropathol. 2007;114:97-109.
2. Duan L, Zhang Y, Fu W, Geng S. Rosette-forming glioneuronal tumor originating from the spinal cord: report of two cases and literature review. World Neurosurg. 2017;98:875.e1-875.e7. Figure 2. Histopathologic examination showing a mixed glial and neurocytic tumor with neurocytic rosettes. (A) Neurocytic rosettes and columns were composed of a neuropil core surrounded by neurocytic nuclei. The glial component was less abundant (hematoxylin-eosin stain; 200). (B) The neuropil in the center of the neurocytic rosettes was immunolabeled with antisynaptophysin. (C) Neurocytic rosettes were surrounded by NeuNþ. (D) The proliferative index (Ki67) increased up to 8% in the glial component (200).
tumor with neurocytic rosettes (Figure 2), typical of rosette-forming glioneuronal tumor (RGNT). Symptoms of intracranial hypertension persisted initially, probably because of leptomeningitis, and ventriculoperitoneal shunt was performed. Six months after surgery, the patient had fully recovered: normal gait, no sensory or motor deficiency, no vesicosphincterian disorder, and no pyramidal syndrome. She only complained of episodic headaches. Follow-up magnetic resonance imaging (performed at 6 months) showed a small
tumor remnant with persistent epiduritis and leptomeningitis (see Figure 1D). RGNT is a mixed glioneuronal tumor of the central nervous system. It has recently been included in the World Health Organization classification as a low-grade tumor.1 It usually occurs in young adults, arising from the fourth ventricular region. It can occur in other locations such as the pineal gland, optic chiasm, hypothalamus, and spinal cord.2 For the last one, main differential diagnoses are astrocytoma and ependymoma, low-grade tumors for which cerebrospinal fluid
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3. Qian X, Goumnerova LC, De Girolami U, Cibas ES. Cerebrospinal fluid cytology in patients with ependymoma: a bi-institutional retrospective study. Cancer. 2008;114:307-314.
4. Medhi G, Prasad C, Saini J, Pendharkar H, Bhat MD, Pandey P, et al. Imaging features of rosette-forming glioneuronal tumours (RGNTs): a series of seven cases. Eur Radiol. 2016;26:262-270.
Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. Received 15 June 2018; accepted 6 August 2018 Citation: World Neurosurg. (2018) 119:242-243. https://doi.org/10.1016/j.wneu.2018.08.035 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2018 Elsevier Inc. All rights reserved.
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