The restricted access materials were immobilized on steel and platinum wires. The selective coating eliminated most of the matrix interference, which allowed the coupling to mass spectrometry without further purification. The SPME devices were interfaced to mass spectrometry by electronanospray. Several experimental set-ups are described and discussed herein. For the in situ extraction of peptides from the tryptic digests, trypsin was immobilized both on steel wires and on the inside wall of a vial.
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Metrics details. In Neurofibromatosis type 1, cerebral Unidentified Bright Objects are a well-known benign entity that has been extensively reported in the literature. In our case series, we wish to focus on a further possible location of such lesions, the spinal cord, which we have defined as medullary Unidentified Bright Objects. These have been, to our knowledge, scarcely described in previous works.
In all of our patients, these lesions were completely asymptomatic and reported on Magnetic Resonance exams the patients underwent for other clinical indications.
The aim of our work is to increase awareness of the possibility of medullary Unidentified Bright Objects in Neurofibromatosis type 1 patients, which can simulate neoplastic lesions, suggesting a more conservative approach in these cases. Peer Review reports. Neurofibromatosis type 1 NF1 is a rare prevalence of 1 in newborns autosomal dominant genetic disorder [ 1 ].
Spinal neoplasms in NF1 patients can be both extramedullary neurofibromas and malignant peripheral nerve sheath tumors and intramedullary astrocytomas, ependymomas and gangliogliomas.
We report seven cases of NF1, followed at our referral center, who shared intramedullary alterations characterized by multiple foci of high signal in T2WI similar to unidentified bright objects UBOs normally reported in the brain of NF1 patients [ 6 , 7 ]. An 8-year old child with two older brothers presented with global developmental delays, genu and cubitus valgum, and bilateral clubfoot with a secondary gait disturbance. The neurological exam was negative.
He underwent an X-ray exam of the spine, because of a mild scoliosis, showing scalloping of the posterior wall of T6-T9 vertebral bodies for which we performed an MR exam of the spine. The MR scan showed three intramedullary hyperintense lesions on T2WI localized in the cervical and thoracic tracts. The largest of these lesions was localized in the cervical tract C1-C6 and presented a tumor-like appearance and was initially diagnosed as a low-grade glial neoplasm.
Three months later, a follow-up MR exam of the spine was performed, showing partial spontaneous regression of the cervical spine lesion and a stability of the two other T2WI-hyperintense spinal lesions. On the subsequent MR follow-up exams done annually for three years and then biannually for 6 more years, the cervical lesion showed further spontaneous regression and then was unchanged through the end of the studies Fig. In the light of these observations and evidence of clinical stability, the initial hypothesis of a low-grade glial neoplasm was abandoned and the lesions were reclassified as medullary UBOs.
Patient number 1. Other smaller lesions with similar features are evident in the DD11 a region that were less evident in the last control. This patient was a year-old female with normal development and growth. She was the only child of a healthy couple. The subsequent brain MR exam showed multiple cerebral and brainstem T2WI-hyperintense, non-enhancing lesions, which were diagnosed as UBOs, a diffuse fornix thickening, brainstem enlargement and a unilateral non-enhancing optic nerve glioma.
An additional nodular lesion, which presented enhancement on post-contrast T1WI, was found in the right cerebellar hemisphere and was identified as a pilocytic astrocytoma. Additional exams, including ophthalmological and endocrinological essays revealed no further abnormalities. The posterior fossa neoplasm showed clinical and radiological progression at further examinations and the patient underwent surgical removal of the lesion at the age of nine, with an improvement of the dysphagia and ataxia.
She then developed a painful dorsal scoliosis for which X-rays of the spine were performed showing only a schisis of the posterior arch of S1, leading to a spinal MR to exclude the presence of neurofibromas. We found multiple small intramedullary lesions which were hyperintense on T2WI, had blurred margins, located mostly in the central medullary region and in the cervical spine, some of which presented a tumor-like appearance.
None of these lesions showed enhancement on post-contrast T1WI. After a two-year MR follow-up, all of the lesions remained unchanged and were diagnosed as medullary UBOs. A year-old female with normal development and growth presented for care. At the age of twelve she was diagnosed with NF1, inherited from her father, and was noted to have lumbar scoliosis associated with lower limb length asymmetry, Lisch nodules, multiple cutaneous neurofibromas, cutaneous angiomas and freckles.
She developed a painful dorsal scoliosis for which she underwent a spinal MR exam showing three T2WI and T1WI-hyperintense spinal lesions localized in the thoracic spine with a tumor-like appearance. During the 9-year MR follow up, these lesions remained stable without the onset of any new neurological symptoms.
Therefore, they were identified as medullary UBOs Fig. Patient number 3. A male patient who had a positive family history for NF1 father was evaluated. He presented with cutaneous neurofibromas, macrocephaly, and short stature.
In addition, a bilateral optic nerve pallor was noted for which he underwent a brain MR, showing multiple UBOs, non-enhancing bilateral optic gliomas and a pilocytic astrocytoma of the left thalamus. The exam also showed a small T2WI-hyperintense spinal lesion at the level of C1. The subsequent spinal MR examination confirmed the isolated cervical tumor-like lesion on the right side of the cord which showed no enhancement after gadolinium injection and with well-defined margins Fig.
This lesion also had high signal intensity in ADC maps. Follow up exams in the next two years showed no significant variation in the characteristics of the aforementioned lesion. Patient number 4. A well-defined, T2-hyperintense, T1-hypointense tumor-like lesion localized on the right side of the bulbo-medullary junction.
It presents high signal intensity on the ADC map due to intramyelinic edema. An 8-year-old male with no family history of NF1 was evaluated and found to have normal psychomotor development and growth. He presented typical features of NF1 and mild back pain for which a spinal MR exam was performed. It showed four small tumor-like lesions of the spinal cord which were moderately hyperintense on T2WI.
These lesions were barely visible in sagittal scans, but axial images better defined the presence and characteristics of the aforementioned lesions.
None of these lesions showed enhancement on post-contrast T1WI and they showed no evolution in the follow up exam one year later. This year-old male patient had no family history for NF1 but had global development delays and mild congenital hypotonia. A brain MR examination, performed at the age of 10, showed a pre-rolandic pilocytic astrocytoma for which the patient underwent surgery.
A spinal MR exam was performed because of the onset of a painful dorsal scoliosis. It showed four tumor-like lesions of the spinal cord and of the conus medullaris which were hyperintense on T2WI and showed no enhancement on post-contrast T1WI.
The neurological examination did not reveal any focal deficit. Neuropsycological development and growth were normal. He underwent the first MR exam at our institution as he presented persistent headache and a reduction of the visual acuity, showing a low-grade astrocytoma localized in the tegmentum of the midbrain causing a triventricular hydrocephalus.
An incidental lesion of the cervical spine was detected for which a spine MR was performed. Three tumor-like, T2WI-hyperintense lesions were detected, none of which showed enhancement on T1WI after gadolinium injection.
In previous studies, brain UBOs have been variously defined: hamartomas, altered myelination, or heterotopias [ 8 , 9 , 10 ]. This was correlated to intramyelinic edema. A reduction in the cellularity of the white matter was seen as well, together with an increased proliferation of glial cells [ 11 ].
More recent studies have confirmed this finding by using non-invasive MR techniques which showed a modification of the microstructural compartmentalization with an increase of extracellular-like intracellular water, an indication of intramyelinic edema, in UBOs confirming the previously mentioned histological findings [ 12 ].
Rare cases of ependymomas 4 cases [ 14 ] and gangliogliomas [ 15 , 16 ] have also been reported in NF1 patients. These lesions are almost always symptomatic, single, have an inhomogeneous signal, often enhance in post-contrast T1WI and usually show progression in follow-up exams. To our knowledge only one previous report of a medullary lesion in a patient with NF1, analogous to those herein documented in our patients, has been published as of this date.
The lesion, in line with the knowledge of the time, was defined as a hamartomatous spinal cord lesion [ 17 ]. We report seven additional cases presenting such lesions localized in different segments of the spine, mainly in the cervical segment, describing their MR features and long-term clinical and radiological follow up. In our experience, patients more frequently had multiple asymptomatic medullary lesions, with a tumor-like appearance, always hyperintense in T2WI, hypo, iso or slightly hyperintense in T1WI, and were never enhancing in post-contrast T1WI.
For these reasons we hope to expand the population for future studies. Even if screening for mUBOs is not an indication for routine spinal MR exams, MR studies of the spine may be done in case of other symptomatic lesions. Knowledge about these benign mUBOs is critical for the correct interpretation of the images and providing appropriate prognostic information.
The presence of mUBOs might have been severely underestimated in the past due to the asymptomatic nature of these lesions. In all our patients the diagnosis was made incidentally in spinal or brain MR exams they underwent for concurrent symptomatic conditions painful scoliosis, brain lesions.
The aim of our work is to increase awareness of the possibility of mUBOs in NF1 patients which can simulate neoplastic lesions, suggesting a more conservative approach. Birth incidence and prevalence of tumor-prone syndromes: estimates from a UK family genetic register service. Am J Med Genet. Brain volume in children with neurofibromatosis type 1: relation to neuropsychological status. Relationship of cognitive functioning, whole brain volumes, and T2-weighted hyperintensities in neurofibromatosis J Child Neurol.
Prospective evaluation of the brain in asymptomatic children with neurofibromatosis type 1: relationship of macrocephaly to T1 relaxation changes and structural brain abnormalities. Brain morphometry, T2-weighted hyperintensities, and IQ in children with neurofibromatosis type 1.
Arch Neurol. MRI abnormalities in neurofibromatosis type 1 NF1 : a study of men and mice. Brain and Development. Use of "unidentified bright objects" on MRI for diagnosis of neurofibromatosis 1 in children. The central nervous system manifestations of the phakomatoses on MR. Radiol Clin N Am. The phakomatoses. Cranial MR imaging in neurofibromatosis. Neurofibromatosis type 1: pathologic substrate of high-signal-intensity foci in the brain.
Characterizing the microstructural basis of "unidentified bright objects" in neurofibromatosis type 1: a combined in vivo multicomponent T2 relaxation and multi-shell diffusion MRI analysis. Neuroimage Clin. Tortori-Donati P, Rossi A. Pediatric Neuroradiology. Brain, Head and Neck, Spine. Springer ; Spinal cord ependymoma associated with neurofibromatosis 1: case report and review of the literature.
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Medullary unidentified bright objects in Neurofibromatosis type 1: a case series
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