Chronic Basal Ganglia Infarction With PCR-Identified Paeniclostridium sordellii: A Rare Neuropathological Case Report

Sep 30, 2026

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A rare neuropathological case report describes a 67-year-old man with metabolic encephalopathy and central diabetes insipidus, later found deceased after hospitalization for acute metabolic derangements. Brain imaging showed bilateral basal ganglia abnormalities progressing to an enhancing anterior commissure lesion suspicious for neoplasm. Postmortem evaluation demonstrated reactive gliosis, atypical lymphocytic inflammation, mild hydrocephalus, hippocampal atrophy, vascular congestion, microthrombi, and oligodendrocyte loss, without hemorrhage. Next-generation sequencing confirmed Paeniclostridium sordellii infection despite negative cultures, after HLH and CNS lymphoma were microscopically excluded.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages5

Reading Time13 min

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Background

Case Presentation

Neuropathologic Findings

Differential Diagnosis

Conclusion

Wiley Case Reports in Pathology Volume 2026, Article ID 7304864, 5 pages [https://doi.org/10.1155/crip/7304864](https://doi.org/10.1155/crip/7304864) Case Report Chronic Basal Ganglia Infarction With PCR-Identified Paeniclostridium sordellii: A Rare Neuropathological Case Report Cassandra Lamm , Angus Toland , and Samuel Guzman Department of Pathology, University of Colorado, Anschutz Medical Center, Aurora, Colorado, USA Correspondence should be addressed to Cassandra Lamm; [cassandra.lamm@cuanschutz.edu](cassandra.lamm@cuanschutz.edu) Received 12 August 2025; Revised 28 November 2025; Accepted 16 December 2025 Academic Editor: Amit Agrawal Copyright © 2026 Cassandra Lamm et al. Case Reports in Pathology published by John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. Background: Within 1 month of diagnosis, 40% of patients with positive blood cultures will develop CNS complications. Rare pathogens, that is, Paeniclostridium sordellii, pose diagnostic challenges due to atypical presentations and detection diﬃculties. Case Presentation: A 67-year-old man presented with metabolic encephalopathy and diabetes insipidus. Imaging showed bilateral basal ganglia abnormalities and an enhancing lesion near the anterior commissure, suspicious for neoplasm. Postmortem ﬁndings included reactive gliosis, atypical lymphocytic inﬂammation, and polyclonal plasma cells. NGS performed at the University of Washington conﬁrmed P. sordellii infection. Neuropathologic Findings: The gross and histologic examination showed mild hydrocephalus, right hippocampal atrophy, and anterior commissure–centric inﬂammation. Vascular congestion, arteriosclerosis with microthrombi, and oligodendrocyte loss were present without hemorrhage. Diﬀerential Diagnosis: Hemophagocytic lymphohistiocytosis and CNS lymphoma were considered but ruled out microscopically. Conclusion: This case highlights the importance of considering P. sordellii in CNS inﬂammatory lesions and demonstrates the utility of molecular diagnostics in negative cultures. 1. Introduction Paeniclostridium sordellii is a rare but highly virulent, sporeforming, anaerobic, Gram-positive bacterium. It is found in rural soil, the gastrointestinal tracts of animals and humans, and rarely in vaginal ﬂora [1, 2] . Infections are uncommon but potentially fatal, especially in postpartum or postabortive women, intravenous drug users, and trauma/surgical patients. Clinical presentation often includes afebrile shock with tachycardia, hypotension, leukemoid reaction, hemoconcentration, edema, and hemorrhage. P. sordellii produces a lethal toxin, TcsL, which disrupts endothelial integrity via the SEMA6A and SEMA6B receptors, causing rapid systemic decompensation [3]. In animals, P. sordellii has been implicated in enteric and histotoxic disease in horses, ruminants, and birds, with pathology often demonstrating mucosal necrosis, hemorrhage, and systemic vascular injury [1] . Central nervous system inﬂammation and necrosis due to hemophagocytic lymphohistiocytosis (HLH) can pose a diagnostic challenge when a brain lesion contains a dense lymphohistiocytic inﬁltrate, especially in the absence of systemic ﬁndings [4], highlighting the need for a high index of suspicion anda broad diﬀerential when encountering unusual brain lesions. 2. Case Presentation A 67-year-old man was found deceased at home following an eight-day hospitalization for acute metabolic encephalopathy and severe hypernatremia with a subsequent eight-day inpatient rehabilitation admission. Neurological deﬁcits during 2 Case Reports in Pathology (a) (b) Figure 1: Gross photographs. (a) Right hippocampal atrophy and amygdala enlargement. (b) Anterior commissure lesion. his hospital stay included acute global debility, acute cognitive impairm

FAQs

What clinical features were observed in the patient before death?

The patient presented with metabolic encephalopathy and central diabetes insipidus, with hospital course complications including cognitive impairment, unsteady gait, and persistent blurry vision.

What did imaging suggest during hospitalization?

Imaging first showed bilateral basal ganglia T2 signal abnormalities and later an enhancing lesion near the anterior commissure, which was suspicious for a neoplasm.

How was the pathogen identified despite negative cultures?

Cultures of cerebrospinal fluid were negative, but next-generation sequencing performed at the University of Washington confirmed Paeniclostridium sordellii infection.

Sep 30, 2026

Uploaded by Aurelia