The major underlying diseases and comorbidities in the ARF patients are shown in Table 2 . BBP was present in 33.9% of the patients (1,597 cases) and was the most frequent pulmonary complication found at the time of autopsy. Cancer was the second most frequent complication; it was observed in 28.1% of the patients (1,324 cases), followed by severe sepsis and/or septic shock in 14.3% (675), liver cirrhosis in 13.6% (639), HIV/AIDS in 10.4% (490), pulmonary embolism in 9.0% (426), acute myocardial The multivariate analysis, with the statistically significant associations between the most prevalent diseases/comorbidities and the different histopathological findings, is shown in Table 3 .