INTRODUCTION Granulomatous inflammation is a distinctive ...

There are few reported cases of patients with ring or nodular enhancing lesions (Wilms et al.,
1992; Ashdown et al., 1994). In a case of a bone marrow transplant recipient who survived, there
was evolution within several weeks from an infarct to a granuloma, seen as a peripheral rim of
low signal intensity on T2-weighted MR images that enhanced after contrast administration
(Miaux et al., 1994). However, most of the reported cases of granulomas (Gupta et al., 1990;
Coulthard et al., 1991; Wilms et al., 1992) are the result of initial involvement of the paranasal
sinuses and/or the orbits and subsequent contiguous spread to the CNS. These lesions present as
low- or intermediate- signal lesions on long repetition time MR images (Wilms et al., 1992) with
contrast enhancement on CT or MR scans. These cases concern mild to moderate
immunocompromised or nonimmunocompromised patients. Most of these patients survived after
several weeks or months of evolution. (Gupta et al., 1990; Epstein et al., 1991).
Brain abscess resulting from Aspergillus infection is nonspecific on CT scan, typically showing a
low-attenuation lesion with an isodense to slightly hyperdense wall, which shows moderate-to-avid
enhancement. MR imaging findings may show a low-intensity rim surrounding the abscess with
surrounding vasogenic edema on T2-weighted images (figure 7) (Metwally, 2006-3). Pathologic
analysis of the wall has shown hemosiderin-laden macrophages and dense population of
organisms, which may account for the drop in T2 signal intensity (Cox et al., 1992; Metwally,
2006-3). Ashdown et al in 1994 reported MR findings in four cases of abscesses in mildly to
moderately immunocompromised patients. The lesions presented hypointense rings within
surrounding edema on T2-weighted images. There was enhancement of the rings on contrastenhanced
T1-weighted images.
Biopsy
Definitive diagnosis requires biopsy or aspiration of a cerebral lesion, but performance of these
procedures is often precluded by a patient’s clinical status or by coagulation problems. An
inferential diagnosis is possible if invasive aspergillosis is documented at other sites (david, 1998).
Treatment
Figure 7. Aspergillosis
Magnetic resonance
images, A (T2weighted)
shows a
multiloculated abscess
with much surrounding
edema. B, T1-weighted
sagittal image of same
patient showing the
large abscess and
surrounding edema,
although it is less
obvious than on the T2weighted
image (David,
1998)
Aggressive neurosurgical intervention for surgical removal of Aspergillus abscesses, granulomas,
and focally infarcted brain, correction of underlying risk factors, amphotericin B combined with
flucytosine and treatment of the source of infection should form the mainstay of the management
(Nadkarni and Goel, 2005).
Surgical debridement enhances abscess penetration by removal of necrotic debris. Radical