Multifocal streptococcus intermedius abscess mimicking neurocysticercosis clinical and radiological findings: A case report and literature review

TL;DR

A case of rare brain abscess caused by Streptococcus intermedius was mistaken for a parasitic infection, highlighting the importance of MRI and biopsy for accurate diagnosis.

Contribution

This case report demonstrates that S. intermedius abscesses can mimic neurocysticercosis in immunocompetent patients and emphasizes the need for early biopsy and MRI evaluation.

Findings

Multifocal S. intermedius abscesses in an immunocompetent patient presented with MRI features resembling neurocysticercosis.

MRI characteristics such as restricted diffusion and peripheral susceptibility helped distinguish pyogenic abscess from parasitic infection.

Prompt treatment with ceftriaxone and metronidazole led to clinical improvement and radiological resolution.

Abstract

Streptococcus intermedius is an opportunistic pathogen capable of causing rapidly progressive, life-threatening cerebral abscesses. Diagnosis can be difficult because clinical features are nonspecific, cerebrospinal fluid findings may be negative, and biopsy results take time. Neuroimaging therefore plays a crucial role. While most reported S. intermedius abscesses present as a single lesion, we describe an immunocompetent young man with unusual multifocal brain involvement initially mistaken for neurocysticercosis. A 33-year-old male presented with fever, headache, and rapidly progressive confusion. CT brain was unremarkable, whereas MRI demonstrated multiple ring-enhancing lesions with marked diffusion restriction across both hemispheres, the brainstem, and cerebellum. These were first interpreted as neurocysticercosis; however, stereotactic biopsy confirmed S. intermedius. Retrospective MRI review showed features favouring pyogenic abscess—uniform profound restricted diffusion, peripheral susceptibility from haemorrhage, and absence of a scolex. The patient was already receiving ceftriaxone for pneumonia, which also covers S. intermedius, and improved clinically with subsequent radiological resolution. This case highlights that S. intermedius abscesses may occur in immunocompetent hosts and closely mimic parasitic infection. Careful evaluation of MRI characteristics and early biopsy are essential for correct diagnosis. Prompt treatment with ceftriaxone and metronidazole can be lifesaving, and increased awareness may prevent future misdiagnosis.

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