[Histopathological diagnosis of an intoxication]. / Une intoxication de diagnostic histologique.

Ethylene glycol poisoning is relatively rare, with around a hundred cases reported each year in France. Its diagnosis is often challenging and delayed because of a several hours' free interval between ingestion of the toxic and the onset of the first symptoms. Ethylene glycol is a colorless and odorless liquid primarily found in automotive coolants, whose toxicity is linked to its hepatic metabolites. Histologically, ethylene glycol poisoning is characterized by abundant tissular deposits of calcium oxalate crystals. Under polarized light, these crystals appear birefringent and iridescent. Their microscopic appearance and their distribution are pathognomonic of oxalosis. Due to its frequent misleading presentation, the diagnosis of ethylene glycol poisoning is sometimes only made after an autopsy. Hereafter, we report the case of a 59-year-old man diagnosed with ethylene glycol intoxication after a post-mortem histopathological examination of organs.

CSF interleukin 6 is a useful marker to distinguish pseudotumoral CNS inflammatory diseases from primary CNS lymphoma.

BACKGROUND: Interleukin 6 (IL-6) is a pleomorphic cytokine that can be found in the cerebrospinal fluid (CSF) in a wide spectrum of inflammatory pathologies of the central nervous system (CNS). OBJECTIVE: Our aim was to characterize the diagnostic significance of CSF IL-6 among various CNS inflammatory diseases with pseudotumoral lesions (CNSID) and primary CNS lymphoma (PCNSL). METHODS: We retrospectively analyzed the CSF IL-6 concentrations in 43 consecutive patients with suspected PCNSL. A total of 28 patients were positively diagnosed with PCNSL and 15 with CNSID. We verified the results with CSF IL-10, an established biomarker for PCNSL. RESULTS: In the PCNSL group, the median CSF IL-6 concentration was 8 pg/ml, interquartile range (IQR) 5-18.5. For the patients with CNSID, the median concentration was 70 pg/ml, IQR 5-1368. A group comparison showed significantly higher CSF IL-6 levels in patients with CNSID than in those with PCNSL (p = 0.032). Moreover, IL-6 was correlated with CSF cell count in the CNSID group (r = 0.56, p = 0.028), but not in the PCNSL group (r = 0.3, p = 0.13). We found significantly higher CSF IL-10 levels in patients with PCNSL than in patients with CNS inflammatory lesions (p < 0.001). DISCUSSION AND CONCLUSIONS: Our study suggests that CSF IL-6 levels could represent, in addition to CSF IL-10, a useful biomarker in the differential diagnosis of CNSID and suspected PCNSL.