Brucellosis is a zoonotic bacterial infection which is transmitted to humans from infected animals and is endemic in many parts of the world including Saudi Arabia. In this article, we report a case of occupational neurobrucellosis that presented with a space-occupying lesion mimicking a brain tumor. We stress on the importance of obtaining detailed social history including occupation to reach the diagnosis in several conditions including brucellosis. We also stress on taking universal precautions when handling any specimens. It may be advisable that manipulation of all unknown specimens arriving at the laboratory should occur in biological safety cabinet until a highly infectious organism is ruled out. Neurobrucellosis should be included in the differential diagnosis in patients presenting with solitary mass lesion mimicking brain tumor especially in endemic areas or high occupational risk group.
Brucellosis is a zoonotic bacterial infection which is transmitted to humans from infected animals and is endemic in many parts of the world including Saudi Arabia. It is a multisystem disease that may present with a broad spectrum of clinical manifestations including undulant fever and musculoskeletal symptoms and signs [
A 52-year-old female patient, who works as a microbiologist, presented with a headache, dizziness, and partial seizures. The onset of symptoms was subacute with gradual progression. She was previously healthy with no past medical or surgical diseases or events, and she was not using any medications. There was no history of blood transfusion, raw milk ingestion, tick bites, or drug abuse. She was married with three children. Physical examination showed normal higher mental functions including speech. Cranial nerve examination was unremarkable apart from mild papilledema. Her tendon reflexes were symmetrical and normal with downgoing toes. The rest of her neurological and systemic examination was normal including vital signs. Basic hematological workup including complete blood count, liver function test, erythrocyte sedimentation rate, C-reactive protein, and connective tissue screen were all unremarkable. Other unremarkable important tests included syphilis serology, HIV test, mammogram, and tumor markers. Serum
MRI of the brain showing peritrigonal (temporal lobe) deep white matter mass measuring 2.6 × 3.5 cm with surrounding vasogenic edema. There was no restricted diffusion with slightly increased flow at the affected area and normal cerebral blood volume on MR perfusion. Axial and sagittal T1 postgadolinium studies showed minimal enhancement.
DTI images showing a slight reduction in anisotropy and diminished color brightness at the affected region with a normal organization of the fiber tract.
MRI of the brain showing almost complete resolution of the previously noted changes.
Brucellosis is caused by organisms from the bacterial genus
Communication between clinicians and laboratory workers is important to help the laboratory staff take extra precautions during the identification of a specimen. It may be advisable that manipulation of all unknown specimens arriving at the laboratory should occur in biological safety cabinet until a highly infectious organism is ruled out [
Brucellosis is a systemic disease that may involve almost every organ system. The exact mechanism by which the organism reaches the nervous system is still unclear. Involvement of the central nervous system (CNS) has only been detected in 3–5% of patients. Once bacteremia occurs, the organism travels to the meninges producing polyradiculoneuropathy, meningitis, or meningoencephalitis. One of the rare consequences of the direct deleterious effect of the organism invading the CNS is the occurrence of a mass lesion or brain abscess which can be documented radiologically and pathologically. Another possible mechanism is an immune-mediated damage of nervous tissue due to the release of circulating endotoxins or to the immunological and inflammatory reaction of the host to the presence of these organisms within the nervous system or other tissues of the body [
Clinical features of neurobrucellosis include back pain, areflexia, paraparesis, cranial nerve involvement, myelitis, and meningovascular involvement including strokes, neuropathy, or depression. The vestibulocochlear nerve has been reported to be the most commonly affected cranial nerve where the patients present with vestibuloacoustic neuritis or hearing loss [
Laboratory tests conducted for the diagnosis of neurobrucellosis include blood and CSF cultures, serum and CSF agglutination tests, and ELISA. Examination of the CSF typically reveals an elevated protein concentration, a normal or slightly depressed glucose concentration, and a moderate lymphocytic pleocytosis. Although positive blood and CSF cultures are the gold standard for diagnosis, the low rate of
To date, neurobrucellosis presenting with a space-occupying mass mimicking a cerebral tumor has been documented in only three patients [
The treatment of neurobrucellosis is still controversial, and no consensus regarding the best treatment has been established. The primary drugs of choice due to their enhanced CNS penetrance, tolerability, and high gastrointestinal absorption are doxycycline, rifampicin, sulfamethoxazole-trimethoprim, ciprofloxacin, and ceftriaxone. In addition to neurotoxicity, streptomycin has low CSF penetrance and has been accused of being inappropriate. Treatment duration in neurobrucellosis is suggested to be several months (a minimum of 6–8 weeks) depending on the patient’s response and should generally be continued until the CSF analysis has returned to normal and the MRI abnormalities disappear [
We stress on the importance of obtaining detailed social history including occupation to reach the diagnosis in several conditions including brucellosis. We also stress on taking universal precautions when handling any specimens. It may be advisable that manipulation of all unknown specimens arriving at the laboratory should occur in biological safety cabinet until a highly infectious organism is ruled out. Neurobrucellosis should be included in the differential diagnosis in patients presenting with solitary mass lesion mimicking brain tumor especially in endemic areas or high occupational risk group.
The authors declare that they have no conflicts of interests.