Date: 26 November 2013
Halo sign in IPA
Copyright: n/a
Notes:
CT scan of a neutropenia patient with leukaemia who has 2 lesions. One, on the right, is nodular, abuts on the pleura and is surrounded by a (grey) low attenuation area, referred to as the “halo” sign. This is virtually only seen in invasive fungal infections of the lung, especially early in the course of the disease, during neutropenia. The other lesion visible on this scan, posteriorly on the left, is also typical of invasive pulmonary aspergillosis in that it is pleura-based and has sharply angulated sides typical of vascular invasion and infarction of small lung segments. There is the suggestion of a “halo” sign anteriorly, but there is less confidence in this appearance (compared with the other) because it is only on one side of the lesion.
Images library
-
Title
Legend
-
Diagnosis: Aspergilloma with invasive aspergillosis evidence of invasion found in the lumbar spine and brain, in addition to heart.
Fungal endocarditis with NO evidence of bacterial endocarditismia.Additional image details:
A. Normal chest X ray:
This (normal) chest X-ray was taken about 6 weeks before endocarditis was diagnosed, and 3 months before death due to disseminated aspergillosis. No CT scan was done (a chest radiograph has a 10% false negative rate in leukaemic patients, compared with CT).B. Aspergillus niger Fungal ball:
Gross section of lung at autopsy showing a discrete, well-demarcated dark/black mass surrounded by a fibrotic capsule. There was no evidence of local invasion, or infarction. The patient had had acute myeloid leukaemia (M1) and responded poorly to chemotherapy. He developed A.niger endocarditis and disseminated disease to the kidneys, lumbar disc and heart, probably arisiong from this lesion. It is unclear whether this lung lesion was a partially cured ‘mycotic lung sequestrum’ following antifungal therapy, or originated as an aspergilloma. The confirmation of genus and species was obtained by PCR on blood and vegetations.C. Endocarditis:
Macroscopic view of the heart at autopsy, showing an infracted lesion on the papillary muscle of the mitral valve in the left ventricle. In addition the patient had large vegetations, which are not shown here. The confirmation of genus and species was obtained by PCR on blood and vegetations; the pericarditis was a manifestation of disseminated aspergillosis.D. Pericarditis due to Aspergillus niger:
Macroscopic view of the pericardium at autopsy, showing gross chronic haemorrhagic pericarditis. The confirmation of genus and species was obtained by PCR on blood and vegetations; the pericarditis was a manifestation of disseminated aspergillosis.E. Lumbar discitis:
Macroscopic lesion of a lumbar intervertebral vertebral at autopsy, showing haemorrhagic necrosis, caused by hyphal invasion and infarction. The confirmation of genus and species was obtained by PCR on blood and vegetations; the discitis was a manifestation of disseminated aspergillosis.
, 
, 
, 
, 
-
Secondary metabolites, structure diagram: Trivial name – Folipastatin
