Two autopsy cases of pulmonary leukemic infiltration mimicking severe pneumonia in patients with acute myeloid leukemia

Abstract

Although a previous autopsy series demonstrated that pulmonary leukemic infiltration (PLI) is a major pulmonary complication in patients with acute myeloid leukemia (AML), an antemortem diagnosis of PLI is rare. Diverse pulmonary complications cause acute respiratory failure (ARF) in patients with AML undergoing chemotherapy. This article reports two elderly patients with AML who presented with ARF due to PLI mimicking severe pneumonia during induction chemotherapy. Accurate antemortem diagnosis of PLI was almost impossible without pathological examination since the clinical course was not typical of PLI. We recommend considering PLI in patients with AML who have an unknown etiology of ARF.

Keywords: Acute myeloid leukemia; Acute respiratory failure; Autopsy; Pulmonary leukemic infiltration.

Fig. 1

Chest computed tomography (a) on admission and (b) at the time of acute respiratory failure onset in Case 1. Fig. 1c shows flow cytometry of pleural effusion at autopsy in Case 1. Fig. 1d-g shows histopathologic examination of lung tissue at autopsy in Case 1 (d; HE, × 40, e; HE, × 400, f; MPO, × 40, g; MPO, × 400). HE, hematoxylin-eosin; MPO, myeloperoxidase.

Fig. 2

Chest computed tomography on admission (a) and chest X-ray done at the time of acute respiratory failure onset (b) in Case 2. Histopathologic examination at autopsy in Case 2. Fig. 2c-f shows HE staining of the lung (c; HE × 40, d; HE × 400, e; MPO × 40, f; MPO × 400). Fig. 2g-j shows leukemic infiltration in the spleen (g; HE × 40, h; HE × 400). Fig. 2i-j shows in the liver (i; HE × 40, j; HE × 400). HE, hematoxylin-eosin; MPO, myeloperoxidase.