1. EORTC/MSG criteria.

Proven IA	Histopathologic or cytopathologic examination showing hyphae from needle aspiration or biopsy specimen with evidence of associated tissue damage; or positive culture result for a sample obtained by sterile procedure from a normally sterile and clinically or radiologically abnormal site consistent with infection
Probable IA	At least 1 host factor criterion; and 1 microbiological criterion; and 1 major (or 2 minor) clinical criteria from abnormal site consistent with infection
Possible IA	At least 1 host factor criterion; and 1 microbiological or 1 major (or 2 minor) clinical criteria from abnormal site consistent with infection. This category is not recommended for use in clinical trials of antifungal agents

Host factor criteria are, for example, neutropenia, persistent fever, predisposing conditions, prolonged use of corticosteroids.

Microbiological criteria are positive culture from sputum, bronchoalveolar lavage fluid (BAL) samples or from sinus aspirate specimen; positive result for Aspergillus antigen in specimens of BAL, cerebrospinal fluid or two or more blood samples.

Major clinical criteria are, for example, new infiltrates on CT imaging (e.g. halo sign), suggestive radiological findings.

Minor clinical criteria are suggestive symptoms and signs.

The exact definitions of the EORTC/MSG criteria and their host factor, microbiological or clinical criteria can be found here (Ascioglu 2002).

CT: computerised tomography; EORTC: European Organization for Research and Treatment of Cancer; MSG: Mycoses Study Group