CASE 16391 Published on 06.06.2019

A rare case of disseminated infection in non-immunocompromised patient

Section

Neuroradiology

Case Type

Clinical Cases

Authors

Ghassan Almeer, Greg Heath, Brook Adams;

Leeds Teaching Hospitals NHS Trust,

Leeds, UK

Patient

80 years, female

Categories
Area of Interest Musculoskeletal spine, Neuroradiology brain, Neuroradiology spine ; No Imaging Technique
Clinical History

80-year-old lady re-presented with deterioration in vision and systemic illness with weight loss, poor appetite, breathlessness and back pain, two weeks following commencement of high dose Prednisolone for biopsy-proven giant cell arteritis.

Clinical examination revealed bilateral choroidal infiltrates. Therefore, the patient was admitted for full workup.

Imaging Findings

A dedicated Panretinal Photography and Optical Coherence Tomography (Fig. 1a-d) confirmed bilateral choroidal infiltrates and subretinal abscesses. 

MRI of the brain demonstrated multiple supratentorial enhancing lesions with restricted diffusions and surrounding oedema (Fig. 2a, b)

A shallow right-sided subretinal abscess was noted in the nasal quadrant (Fig 2c), and a possible smaller one in the left.

Further investigation with chest, abdomen and pelvis CT with contrast revealed right upper lobe consolidation and a right iliopsoas abscess (Fig 3a, b).

Transoesophageal echocardiogram was performed to exclude endocarditis, with normal results (Fig. 3a).

MRI whole spine with contrast confirmed the clinical suspicion of spondylodiscitis at L4/L5 level (Fig 4a-d).

Blood cultures showed Nocardia cyriacigeorgica.

Discussion

Background:

Endogenous endophthalmitis is an uncommon occurrence [1], and subretinal    abscess is infrequently reported in the literature.
The most common organism reported to cause subretinal abscess is Nocardia [2, 3], particularly in immunocompromised patients.

There are case reports of other organisms such as Pseudomonas aeruginosa [4], Streptococcus viridans [5] and Klebsiella pneumoniae [6] causing subretinal abscess. The bacterial genus Roseomonas was also reported but a lot less frequently [7].

Clinical perspective:

Nocardia species are gram-positive, strictly aerobic bacilli.
The infection is usually acquired through the respiratory tract or the skin.
This species has a tendency to spread from the primary site usually to the lungs, brain, kidney, joints, bones, and eyes. 
In the brain, the spread is usually through the choroid plexuses, and ventriculitis is usually a dominant feature.

Ocular nocardiosis is a rare disease with varying prognosis [8].

Ocular manifestations of this bacteria range from keratitis to endophthalmitis [9, 10]. Severity of disease and symptoms can be highly variable, making diagnosis difficult.

Presentation can range from minimal inflammation to significant vitritis and retinal detachment.

Imaging perspective:

The imaging features of CNS Nocardia are usually of ring-enhancing lesions and ventriculitis.
Our patient presented with disseminated infection with pulmonary, abdominal, spinal, CNS and ocular involvement. 
MRI did not reveal ventriculitis, instead showing multiple ring-enhancing lesions and subretinal abscesses.

Outcome:

Treatment involves systemic sulfonamide therapy. Systemic nocardiosis carries an unsurprisingly poor prognosis given the affected patient population, in part due to the difficulty in establishing the diagnosis and management of diffuse disease.

In a review conducted in 2011 by Eschle-Meniconi et al, 10 (27%) of the reported 36 patients with ocular Nocardia from 1967 to 2007 died [11].

Unfortunately, our patient succumbed to her illness.

Teaching points:

1- Immunocompromised patients are at increased risk of developing opportunistic infection and therefore the threshold for thorough investigation should be low.

2- Nocardiosis should be considered in an mmunocompromised patient with brain and subretinal abscesses.

3- In the setting of multifocal diffusion restriction suggestive of embolic infarcts always carefully check the T2W imaging for associated parenchymal reaction as this can be a clue to their underlying septic nature.

Written patient consent for this case was waived by the Editorial Board. Patient data may have been modified to ensure patient anonymity.

Differential Diagnosis List
Disseminated Nocardia infection
Neurocysticercosis
Tuberculoma
Tumefactive demyelination
Lymphoma
Lymphoproliferative disorders
Sarcoidosis
Non-langerhans cell histocytosis
Melanoma
TB infection
Fungus infection
Final Diagnosis
Disseminated Nocardia infection
Case information
URL: https://www.eurorad.org/case/16391
ISSN: 1563-4086