Influence of host immunosuppression on CT findings in invasive pulmonary aspergillosis

To assess whether the type of immune suppression in patients with hematologic malignancies affects the appearance of invasive pulmonary aspergillosis (IPA) on computed tomography (CT), we retrospectively reviewed the CT findings of 66 consecutive patients who were diagnosed with hematologic malignancies and IPA and correlated the findings to patients' IPA risk factors. In our study these risk factors included neutropenia (n = 34, 52%), stem cell transplantation (SCT; n = 30, 45%), graft versus host disease (GVHD; n = 22, 33%), and steroid use (n = 29, 44%). Nodular lesions were the most common finding on CT (n = 54, 82% of the entire patient population). These were seen in 74% of neutropenic patients (n = 25, P > 0.07), 87% of patients following SCT (n = 26, P > 0.35), 95% of patients with GVHD (n = 21, P = 0.04)), and 83% of those receiving steroids (n = 24, P > 0.45). The hypodense sign was often seen in patients without GVHD (n = 17, 39%; P = 0.003). Tree-in-bud opacities were often observed in patients who underwent SCT (n = 10, 33%; P = 0.03). Thus, peripheral nodular lesions are the most common initial finding of IPA in patients with hematologic malignancies, regardless of the mechanism of immunosuppression.