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Proceedings SNO “Percorsi clinici in Neuroscienze”

malacic degeneration of the postero-lateral medulla Radiologic investigations in our patient suggested the
oblongata and of middle cerebellar peduncle on the diagnosis of cavernoma as more likely without strong
right and showed a small right bulbopontine lesion evidence. However, recurrent bleedings demanded
compatible with a cavernoma with a hemosiderinic surgical biopsy in order to make a definitive diagno-
rim hypointense in the T2-weighted, CISS and SWI sis. Histology revealed a FGFR1 mutated pilocytic
sequences (Figure 1). A new cerebral angiography astrocytoma.
showed no significant changes. Over the course of 4 The FGFR1 gene encoding fibroblast growth factor
years recurrent bleedings occurred with transient receptor 1 has emerged as a frequently altered onco-
clinical worsening. Therefore, on 6 September 2021 gene in the pathogenesis of multiple LGNET sub-
the patient underwent a right bulbopontine open biop- types including pilocytic astrocytoma, DNET,
sy. Histology showed a low-grade glial neoplasm rosette-forming glioneuronal tumor and extraventric-
with oligo-like aspects. The molecular characteriza- ular neurocytoma .
(6)
tion revealed a FGFR1 mutation. Based on the mo- Calixto-Hope G. Lucas et al. performed a compre-
lecular profile, morphological features and location, a hensive genomic and epigenomic characterization on
diagnosis of FGFR1 mutated pilocytic astrocytoma a diverse cohort of 30 LGNET with FGFR1 alter-
was established. The patient underwent MRI staging ations .
(6)
of the entire neuraxis and a lumbosacral lesion com- They observed that FGFR1 alterations occur in a
patible with astrocytoma dissemination was detected. spectrum of lesions with overlapping histological fea-
A chemotherapy protocol with vinorelbine, evero- tures. The pattern of genetic alterations and epigenet-
limus and trametinib was started and is still ongoing. ic signature combined with the site and histologic
features allows accurate classification of these low-
(6)
grade glial tumors .
DISCUSSION In our case, an MRI of the entire neuraxis demon-
strated lumbosacral dissemination of the lesion. We
Brainstem hemorrhages are typically of acute onset opted for a chemotherapeutic treatment with weekly
with variable motor (up to tetra/hemiplegia), sensory, vinorelbine, everolimus for high expression of
respiratory, cranial nerve disorders also with pupil- mTOR and a mek inhibitor (trametinib) for FGFR1
lary abnormalities, and even coma, as a result of base mutation.
or tegmentum involvement .
(1)
Regarding radiological imaging, brain CT remains
the technique of choice for initial evaluation of brain-
CONCLUSIONS
stem hemorrhages due to its rapidity and accessibili-
ty. Although MRI of the brain, despite its longer du-
This illustrative case of brainstem hemorrhage in a
ration and restricted access to the patient, is the most
young patient highlights how, despite suggestive ra-
effective technique for investigating the etiopatho-
diologic images can usually guide the diagnosis and
genesis and assessing the precise extent of the hem-
therapeutic approach, the possibility of rare entities
(4)
orrhage . In one of the classifications of brainstem
that may in some cases warrant aggressive treatment
hemorrhage localization, the “small unilateral
must always be considered. In that context, the indi-
tegmental” type (exclusively in the unilateral tegmen- cation for surgical biopsy arises in order to make a
tum) is associated with the best prognosis, while the
definitive diagnosis and a targeted strategy to prevent
“massive” type (bilateral spread into both the basis
future bleeding.
pontis and the tegmentum) is prognostically the
worst .
(5)
In our case, the hemorrhage was unilateral and
tegmental, extending to the medulla oblongata and REFERENCES
the pons with a typical lateral medullary syndrome
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and facial colliculus syndrome symptomatology. fossa. A study of primary cerebellar and pontine hemor-
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was good and the patient, despite the initial deterio- Neurol 1964; 10 (2): 200-217.
ration of consciousness, displayed slow neurological 2. Nilsson OG, Lindgren A, Brandt L, Säveland H. Predic-
recovery with moderate disability. tion of death in patients with primary intracerebral hem-

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