P14.87 Leptomeningeal dissemination in high grade glioma: Correlation of MRI, cytology and standard CSF indices

BACKGROUND

Only few studies report the incidence of leptomeningeal dissemination (LMD) in patients with high grade glioma (HGG), although LMD is not a rare condition of recurrence. We aimed to describe the diagnostic features and treatment modalities in a series of patients treated for HGG in our institution.

METHODS

Review of clinical presentation, radiological features and CSF analysis in a case series.

RESULTS

17 patients from our institution were diagnosed with LMD. The diagnosis of LMD was based on magnetic resonance image and/or cerebrospinal fluid (CSF) analysis. The spectrum of clinical presentation was broad, mainly intracranial hypertension, impaired general condition, pain, worsening of pre-existing symptoms, and epileptic seizures. Median time from onset of clinical deterioration to diagnosis of LMD was 3 weeks (0–16). Leptomeningial involvement was reported in 6/17 at initial MRI reading, whereas reassessment with careful comparison to previous MRI showed signs of LMD in all patients. CSF analysis revealed pleocytosis (11/17), high proteinorrachia (13/17), elevated lactate levels (15/16), low glucose levels (5/17), and increased CSF pressure (5/9). Nevertheless, diagnostic accuracy of initial CSF cytological analysis was low (2/17). A reassessment of the specimen by an experienced neuropathologist disclosed 1 additional positive and 1 additional suspect cytology. After diagnosis of LMD, salvage treatments comprised Bevacizumab, Lomustine, Fotemustine, liposomal cytarabine and best supportive care. The median overall survival after the diagnosis was 3 months.

DISCUSSION AND CONCLUSIONS

LMD in HGG is not a rare condition of recurrence, and its outcome is poor. It remains a diagnostic challenge, as it may be overlooked on MRI follow-up at its early stage. In case of clinical progression with no overt cause reported on MRI, we recommend careful second MRI reading. In case of doubt lumbar puncture should be performed in order to prove LMD and eliminate infection (i.e. HSV). Upon standard CSF indices, elevated lactate levels should give rise to the suspicion of LMD. Cytological CSF analysis seems to be of low diagnostic yield: This may be improved by faster processing after sampling and by standardized workup including staining with IDH, GFAP and Olig2.

P14.49 Primary central nervous system lymphoma presenting as dementia: do not forget IL10 in CSF analysis

BACKGROUND

Primary central nervous system lymphoma (PCNSL) is a rare form of non-Hodgkin lymphoma that affects the central nervous system without systemic involvement. Clinical presentation depends on its localization: Focal deficits usually lead to prompt neuroradiologic evaluation, whereas cognitive or behavioral changes can lead to diagnostic delay. Rapidly progressive dementia (RPD), defined as a 1- to 2-year course from symptom onset to cognitive and functional debilitation, is a clinical presentation of PCNSL and thus a potentially curable cause of dementia, leading to death if it remains untreated. Nevertheless, its diagnosis is frequently delayed as other origins (CJD, autoimmune, paraneoplastic, infectious, and neurodegenerative disorders) are more frequently considered. We aimed to describe diagnostic features and treatment modalities in a series of patients presenting with RPD diagnosed as PCNSL.

METHODS

Patients with RPD and final diagnosis of PCNSL were retrospectively identified from 2012 to 2019 from the database of our academic teaching hospital. Clinical presentation, neuroimaging, and cerebro-spinal fluid (CSF) analysis were assessed from their medical records. Interleukin (IL) 10 and 6 concentrations were measured by flow cytometry using the cytometric bead array (CBA) technique (BD Biosciences) with a detection limit set at 2.5 pg/ml.

RESULTS

50 patients with diagnosis of PCNSL were identified, 7 (3 women, 4 men) presented with RPD.Median age was 69 years (range 59–84). Time from symptom onset to diagnostic confirmation of PCNSL ranged from 1–12 months (median 3). All patients presented with cognitive impairment (disorientation, memory disorders), accompanied by psycho-behavioral disorders in 6 of them. MRI disclosed enhancing lesions in all patients. Lumbar puncture was performed in 5 patients. All of them presented pleiocytosis, and lymphomatous meningitis was detected in 4/5 of them by cytology or flow cytometry (FCM). Elevated interleukin 10 (IL-10) was found in all patients with available CSF sample, 4 of them had an IL-10/IL-6 ratio >1.

DISCUSSION AND CONCLUSION

Patients presenting with rapidly progressive dementia should be evaluated for treatable forms of dementia. PCSNL has to be considered as soon as possible as diagnostic delay impacts its outcome. Imaging studies, usually contrast-enhanced MRI, is recommended, although nonspecific findings are not uncommon, especially in case of non-enhancing lesions. CSF sampling can help to prove diagnosis of PCNSL by cytology (generally associated with FCM), but it requires an experienced cytologist and immediate sample analysis.IL10 and IL10/6 ratio can be used as a more easily available marker to support suspicion of PNSCL, leading to further specific workup.

ACKNOWLEDGMENTS

NENO & LOC Network

Necrosis and haemorrhage of the putamen in methanol poisoning shown on MRI

Methanol, a highly toxic substance, is used as an industrial solvent and in automobile antifreeze. Acute methanol poisoning produces severe metabolic acidosis and serious neurologic sequelae. We describe a 50-year-old woman with accidental methanol intoxication who was in a vegetative state. MRI showed haemorrhagic necrosis of the putamina and oedema in the deep white matter.