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
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Image A
CT Scan 30/3/99
Showing extreme pleural thickening and 2 small cavities at apex of left lung.
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A 43 year old with smoking related emphysema was admitted to hospital with two separate episodes of haemoptysis. He had been in good health up to 1989, when he was diagnosed as having bilateral pulmonary tuberculosis. At that time a CT scan revealed a cavity in the left upper lobe (20.8cm2) with adjacent confluent infiltrates and pleural thickening. On bronchoscopic examination no abnormalities were noted and endobronchial biopsies did not reveal hyphae.
Over the next 4 years his condition deteriorated and a CT scan showed the left upper lobe cavity had increased to 40cm2. Itraconazole 400mg daily was prescribed. There was some clinical improvement on itraconazole but patient eventually deteriorated with breathlessness and with significant weight loss.
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