Primary Cerebral Abscess due to Nocardia Presenting as ‘Ghost Tumor’

Abstract

We report a case of a primary cerebral abscess due to Nocardia asteroides in a nonimmunocompromised patient with a particular clinical course. The first symptom (right subacute brachial palsy) and the lesion in a computed tomographic (CT) scan (left parietofrontal edema suggestive of brain tumor) disappeared after corticosteroid treatment and the patient was discharged with total recovery. After 2 months she complained of headache and visual disturbance. A new CT scan showed an annular lesion in the left occipital lobe. A cerebral biopsy was diagnosed of nocardia infection. The patient died 2 weeks after this biopsy. A postmortem study showed an occipital brain abscess but not structural abnormalities were seen in the left parietofrontal area. We believe that the first episode could be a local inflammatory response to cerebral implantation of nocardia which disappeared clinically in the CT scan and in the postmortem study after corticosteroid treatment. Then the nocardia could have displaced by the hematological route to the second and definitive cerebral lesion.

Nocardial brain abscess: Review of clinical management

“…12 Although less commonly isolated, N. farcinica is an important member of this group. 21,22 Cerebellar abscesses are good candidates for surgical resection as they are difficult to aspirate and any space-occupying lesion of the posterior fossa may be rapidly life-threatening. 14 The treatment options for nocardial CNS involvement include antimicrobial therapy alone, freehand or stereotactic aspiration/biopsy, 16 and craniotomy plus enucleation, 17 in addition to antibiotic therapy.…”

“…27 For patients who are receiving ongoing steroid or cytotoxic therapy, prolonged therapy and indefinite low-dose prophylaxis should be considered. 10,14,30,31 Given that nocardial abscesses may have a very similar appearance to tumours 21,22 or cerebral infarctions, 32 it could be argued that an earlier diagnosis of some nocardial abscesses is possible in the post-MRI era. According to Mamelak et al, 10 the mortality rate declined with the advent of CT, to 20% for immunocompetent and 55% for immunocompromised patients.…”

Nocardia species: host-parasite relationships

“…Of these CNS infections, 42% (100 of 238) occurred in previously healthy individuals with no identifiable predisposing factor (1, 4, 5, 8, 19, 22, 26, 31, 32, 34, 36-40, 43, 44, 50, 51, 102, 106, 109, 112, 121, 132, 133, 135, 138, 144, 152, 153, 159, 165, 166, 178, 179, 181, 192, 196, 198, 201, 203, 215, 228, 231, 233, 238, 239, 253, 255, 264, 267, 271, 276, 288, 292, 294, 298, 299, 301, 304, 308, 310, 314, 320, 323, 327, 330, 341, 342, 344, 357, 361, 364, 365, 168-171, 175-183, 186-188, 190-198, 201-204, 206, 207, 213-220, 222, 224, 225, 228, 231-239, 241, 247-255, 257-262, 264, (357,528,562,582). Thus, the signs and symptoms expressed following brain infection are variable, and there may not be any outward neurologic manifestations (357,528,562,582). The lesions in the brain may be recognized as either granulomata with giant cells (228,712) or, more frequently, abscesses in any location within the brain (Fig.…”

“…Diffuse cerebral infiltration with no focal lesions may also be present (181). Frequently, nocardial lesions are localized in the parietal, frontal, and occipital cerebral cortex (132,228,503,562,658,715), basal ganglia (437,683), midbrain (682), and brain stem (pons) (109,138,309,484,505). Furthermore, there may be meningitis with or without involvement of other portions of the brain (138,142,228,267,378,430,517,625).…”

Nocardia species: host-parasite relationships.

“…378, 380,386,394,396,397,414,418,419,422,428,430,433,434,437,440,448,456,459,461,466,468,477,480,482,484,492,495,503,505,510,512,515,517,520,522,523,525,534,537,538,545,551,553,555,560,562,564,576,582,588,592,602,…”