Rosette-forming glioneuronal tumor originating in the hypothalamus

Abstract

Rosette-forming glioneuronal tumors (RGNT) of the fourth ventricle are slow-growing tumors that primarily involve the fourth ventricular region. We here report the first patient, an 8-year-old girl, with an RGNT originating in the hypothalamus and manifesting with precocious puberty. After partial removal, the remaining tumor showed rapid enlargement, and the pathologic diagnosis at the second surgery revealed histopathologic features similar to those found in the initial samples, including biphasic patterns of neurocytic rosettes and GFAP-stained astrocytic components. These tumor cells had mildly atypical nuclei; however, mitotic figures and necrosis were absent. Eosinophilic granular bodies and a glomeruloid vasculature were found, but Rosenthal fibers were absent. The Ki-67 proliferative index was 3.5 % (vs 1.1 % at the initial surgery). No recurrence was recorded during the 3-year period after the proton radiotherapy.

Rosette-forming glioneuronal tumor: an illustrative case and a systematic review

“… 21 Silveira et al also described the dissemination of tumor with drop metastasis in the lumbar spine only 1 month after initial imaging and biopsy of the tumor. 69 Other reports have described similarly quick tumor recurrences postoperatively after 4 months 6 and 9 months. 75 However, recurrences have also been reported as late as 9 years after initial resection.…”

“… 1 In 2007, the RGNT was designated as a World Health Organization (WHO) Grade I tumor and described as a slow-growing tumor typically localized to the fourth ventricle and composed of neurocytes that form neurocytic rosettes and glial components similar to those of the pilocytic astrocytoma. 2 In the 2016 WHO classification, the RGNT was again classified as a Grade I tumor and listed under the category of “neuronal and mixed neuronal-glial tumors.” 3 Various other anatomical sites of origin have been reported, including the supratentorial ventricles, 4 pineal gland, 5 hypothalamus, 6 optic chiasm, 7 , 8 and spinal cord. 9–11 Due to the rarity of the RGNT, little is known about its epidemiology and natural history.…”

Rosette‐forming glioneuronal tumor of the fourth ventricle; A case report and review of the literature

“…However, recent reports show that RGNTs may occur outside the characteristic locations, such as spinal cord, optic chiasm, tectum, pineal gland, third ventricle, cerebellopontine angle, and hypothalamus. 5,[15][16][17][18][19][20][21][22] The spectrum of symptoms is wide and depends on the size and the exact location of the lesion. It includes headache, dizziness, ataxia, dysarthria, blurred vision, vomiting, hemiparesthesia, tinnitus, neck pain, diplopia, nausea, somnolence, hand tremor, anisocoria, and cranial nerve palsy.. [8][9][10]21,23,24 On the other hand, incidentally discovered tumors in asymptomatic patients have also been reported.…”

“…However, recent reports show that RGNTs may occur outside the characteristic locations, such as spinal cord, optic chiasm, tectum, pineal gland, third ventricle, cerebellopontine angle, and hypothalamus. 5 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22…”

“… 6 , 8 Surgery with subtotal or gross total resection of tumor mass is the preferred treatment for RGNT and the recurrences are exceptional. 8 , 20 Adjuvant radiotherapy and chemotherapy in patients with RGNT are not recommended except in cases with frankly invasive or recurrent tumors. 16 RGNTs with aggressive behavior in terms of in situ progression/recurrence or dissemination have been reported before.…”