Spinal intramedullary abscess due to Candida albicans in an immunocompetent patient: A rare case report.

BACKGROUND: A spinal intramedullary abscess is a rare clinical entity in which patients classically present with a subacute myelopathy and progressive paraplegia, sensory deficits, and/or bowel and bladder dysfunction. We report the second case of spinal intramedullary abscess caused by Candida albicans to ever be published and the first case of its kind to be surgically managed. CASE DESCRIPTION: A 44-year-old female presented with severe lumbar pain associated with paraparesis, incontinence, and paraplegia. She reported multiple hospital admissions and had a history of seizures, having already undergone treatment for neurotuberculosis and fungal infection of the central nervous system unsuccessfully. Nevertheless, no laboratory evidence of immunosuppression was identified on further investigation. Magnetic resonance imaging showed a D10-D11, well-circumscribed, intramedullary mass within the conus, which was hypointense on T1-weighted imaging and hyperintense on T2/STIR weighted. The patient underwent surgery for removal and biopsy of the lesion, which provided the diagnosis of an intramedullary abscess caused by C. albicans, a very rare condition with only one case reported in literature so far.
CONCLUSION: C. albicans intramedullary abscess is a very rare clinical entity, especially in immunocompetent patients. We highlight C. albicans as an important etiology that must be considered in differential diagnosis. Critical evaluation of every case, early diagnosis, timely referral and surgical management of the abscess is essential to improve neurological outcome. Copyright:

INTRODUCTION

Involvement of the central nervous system (CNS) by Candida sp. usually leads to meningitis and cerebral microabscesses, especially in immunocompromised individuals or when anatomic barriers are breached by surgery or implanted devices.[17] However, CNS involvement in immunocompetent patients represents an even rarer entity.[7] To the best of our knowledge, Candida albicans intramedullary abscesses had only been reported once in an immunocompetent who did not need neurosurgery.[39] Here, we report a cauda equina C. albicans intramedullary abscess, representing the second report in literature and the first case approached surgically.

CASE REPORT

A 44-year-old female patient sought the neurosurgery service at Hospital Santa Paula with a complaint of lower back pain associated with paraparesis for 2 years with progressive worsening of the condition between crises. She reported development of paraplegia in the past year.

In an investigation of multiple hospital admissions, she previously underwent treatment for CNS fungal infection and neurotuberculosis in late 2020 with amphotericin B (for 6 weeks) followed by voriconazole (for 4 weeks) with an ineffective result. The cerebrospinal fluid (CSF) contained 43 cells (75% lymphocytes, monocytes 22%, macrophages 3%), protein 175 mg/dL; glucose 26 mg/dL; lactic acid 42 mg/dL; lactate dehydrogenase 30 U/L; adenosinedeaminase 6.2 U/L; gamma globulin 31.62%; microbiology negative; antibodies for syphilis, Borrelia burgdorferi, toxoplasmosis, cytomegalovirus (CMV), herpes simplex 1 and 2, herpes zoster, cysticercosis, human immunodeficiency virus (HIV), and human T-lymphotropic virus were not reactive; no cancerous cells were identified. She also presented a history of seizures and meningitis.

On neurological examination, the patient presented with dysarthria, horizontal nystagmus with preservation of extrinsic eye movement, Grade III strength in upper limbs with wrist spasticity, plegia in lower limbs, and anesthesia from the T12 level without proprioception. She also presented with bicipital, tricipital, and styloradial hyperreflexia in upper limbs, with bilateral exaltation points and positive Hoffmann’s sign, besides patellar and aquilean areflexia, and negative Babinski’s sign.

For better evaluation, magnetic resonance imaging (MRI) images of the brain and spine were requested. Brain MRI showed thickening and leptomeningeal impregnation by gadolinium compromising both lateral fissures, insula, and frontotemporal operculum, evidencing diffuse pachymeningitis [Figure 1]. The MRI of the spine showed marked diffuse leptomeningeal enhancement along the anterior and posterior pial surfaces of all medullary segments, as well as medullary cone, marked segmental narrowing of the medulla at T10-T11 levels with hypersignal in the weighted sequences at T1 and T2/STIR associated with the tumefactive effect of the cone spinal cord with intramedullary lesion at this level, hypointense in T1-weighted image and hyperintense in T2/STIR weighted [Figure 2].

Figure 1:

Preoperative magnetic resonance imaging. (a) Coronal gadolinium-enhanced image, (b) sagittal gadolinium-enhanced image, (c) axial T2/FLAIR-weighted image showing a slight reduction in the thickness of the leptomeningeal impregnation of the lateral fissures and frontotemporal operculum on both sides suggestive of diffuse pachymeningitis.

Figure 2:

Preoperative magnetic resonance imaging. (a) Axial T2/STIR-weighted image, sagittal T1 and T2/STIR-weighted image, (c) sagittal T2/STIR-weighted showing the intramedullary abscess hypointense on images (a and b) and hyperintense on image (c).

From the imaging findings and their relationship with the clinic, the patient underwent surgery and biopsy of the lesion. A T10-T11 laminectomy was performed and, after straight opening of the dura mater, a whitish lesion was found in the intramedullary region, suggestive of an abscess, being, therefore, drained and biopsied for analysis [Figure 3].

Figure 3:

Intramedullary abscess drainage surgery.

The culture of the surgical specimen tested positive for C. albicans and the histopathological evaluation of the lesion revealed extensive fibrinoid material and presence of hyaline septate pseudohyphae and fungal spores, with strong impregnation by Grocott methenamine silver stain [Figure 4]. These findings are consistent with intramedullary abscess due to C. albicans infection, being the second case report in the literature.

Figure 4:

Histopathology revealed numerous septate pseudohyphae and fungal spores embedded in fibrinoid material (a, H and E, ×400). There was intense silver impregnation by Grocott methenamine silver stain, suggestive of Candida albicans (b, GMS, ×400).

DISCUSSION

Candida spp. are considered opportunistic commensal pathogens that promote infection under host predisposing conditions.[55] When the CNS is involved in patients with systemic candidiasis, several clinical manifestations can be overlooked due to the severity of the patient’s situation. It is primarily found in immunocompromised hosts[56] or when anatomic barriers are breached by surgery, implanted devices, nonpenetrating blunt trauma to the back, or intermittent systemic corticosteroid,[17] typically leading to decrease in the level of consciousness, meningitis, and cerebral microabscesses.[7] However, other manifestations such as macroabscesses, sometimes suggestive of spinal tumors, are a more rare entity, especially when intramedullary.[56] Nevertheless, infection by Candida spp. has also been reported in immunocompetent individuals, as in this case report, but it is a rare event.[35,38,39,53]

There are a wide array of infectious causes of intramedullary myelitis, most of them caused by B. burgdorferi, Treponema pallidum, Mycobacterium tuberculosis, HIV, herpes simplex virus, varicella-zoster virus, CMV, Epstein-Barr virus), rabies, and schistosomiasis.[22] When the infection leads to an intramedullary spinal cord abscess, it is usually associated with high mortality and neurological morbidity and rarely encountered in modern neurosurgical practice.[10] We reviewed all cases of spinal intramedullary abscesses in the past 10 years [Table 1].[12-73] We found that approximately 68% of patients were male and 32% of female, the median age was 25, 86 years old (4 months – 82 years old), the main location was at thoracic level and the most frequent pathogen was from a tubercular source. Among all the reports, none of them identified an intramedullary abscess caused by C. albicans, which demonstrates the rarity of this entity once again.

Table 1:

Studies published in the past 10 years reporting intramedullary abscess.

C. albicans spinal infection still configures a challenging diagnostic. MRI is useful in diagnosing medullary abscesses, but those infections may mimic a neoplastic process as myxopapillary ependymoma or leptomeningeal carcinomatosis.[7] Besides, the albuminocytologic dissociation often present may come from Guillain–Barré syndrome, cerebral meningitis, malignant lymphoma, spinal hemangioma, multiple sclerosis, central hemorrhagic disease, myelitis, and cerebrospinal infarction, making diagnosis more difficult.[53] However, the CSF of patients with candidal CNS abscesses generally presents no biochemical or cytologic abnormalities. Proteins are usually discreetly high, and a discreet pleocytosis with polymorphonuclear or lymphocytic predominance can be equally frequent,[56] which increases the suspicion of a Candida infection, especially when the diagnosis is uncertain, as in the case presented. In addition, some studies still highlight genes related to candidiasis.[23] Colony-stimulating factor 2, Ras protein-specific guanine nucleotide-releasing factor 1, and phospholipase C gamma 2 are examples related to increased susceptibility to CNS Candida infection, but functional and bioinformatic studies are needed to identify possible variants that could have influenced Candida spp. infection reported in this article. As we have discussed, there are cases with no laboratory evidence of immunodeficiency or no identifiable cause of immunosuppression,[7] as we observed in this case report.

CONCLUSION

C. albicans intramedullary abscess represents a very rare clinical entity, especially in immunocompetent patients. It must, however, be considered as an important etiology for spinal intramedullary abscesses and as a differential diagnosis in intramedullary pathologies. Critical evaluation of every case, early diagnosis, timely referral and surgical management of the abscess is essential to improve neurological outcome.