Proven invasive pulmonary mucormycosis successfully treated with amphotericin B and surgery in patient with acute myeloblastic leukemia: a case report

Abstract

Introduction: Invasive mucormycosis (zygomycosis) is the third most frequent fungal infection in patients with hematologic malignancies. It often results in a fatal outcome mainly due to the difficulty of early diagnosis and its resistance to antimycotics.

Case presentation: A 52-year-old Caucasian man was diagnosed with acute myeloblastic leukemia. Following the induction chemotherapy he developed febrile neutropenia. Meropenem (3×1000mg/day) was introduced empirically. A chest computed tomography showed soft-tissue consolidation change in his right upper lobe. A bronchoscopy was performed and the histology indicated invasive pulmonary aspergillosis based on fungal hypha detection. Also, high risk patients are routinely screened for invasive fungal infections using commercially available serological enzyme-linked immunosorbent assay tests: galactomannan and mannan (Bio-Rad, France), as well as anti-Aspergillus immunoglobulin G and/or immunoglobulin M and anti-Candida immunoglobulin G and/or immunoglobulin M antibodies (Virion-Serion, Germany). Galactomannan showed low positivity and voriconazole therapy (2×400mg/first day; 2×300mg/following days) was implemented. The patient became afebrile and a partial remission of disease was established. After 2 months, the patient developed a fever and a chest multi-slice computed tomography showed soft-tissue mass compressing his upper right bronchus. Voriconazole (2×400mg/first day; 2×300mg/following days) was reintroduced and bronchoscopy was repeated. Histologic examination of the new specimen was done, as well as a revision of the earlier samples in the reference laboratory and the diagnosis was switched to invasive pulmonary mucormycosis. The treatment was changed to amphotericin B colloidal dispersion (1×400mg/day). The complete remission of acute myeloblastic leukemia was verified after 2 months. During his immunerestitution, a high positivity of the anti-Aspergillus immunoglobulin M antibodies was found in a single serum sample and pulmonary radiography was unchanged. A lobectomy of his right upper pulmonary lobe was done and the mycology culture of the lung tissue sample revealed Rhizopus oryzae. He remained in complete remission for more than 1 year.

Conclusions: Invasive mucormycosis was successfully treated with amphotericin B, surgery and secondary itraconazole prophylaxis. As a rare disease invasive mucormycosis is not well understood by the medical community and therefore an improvement of education about prevention, diagnosis and treatment of invasive mucormycosis is necessary.

Figure 1

Findings of pulmonary mucormycosis detected by computed tomography (A, B) and multi-slice computed tomography (C). A) First hospitalization, soft-tissue alveolar-consolidation changes of the anterior and posterior segment of the upper lobe (arrow). B) Second hospitalization, peribronchial circular thickening, with deformation and constriction of all bronchial segments, with peribronchial propagation in the form of irregular, interlobular septal and nodular (up to 1cm) opacities (arrow). Suspected clot masses were viewed in the lumen of the superior vena cava, inferior vena cava, azygos vein and splenic vein. C) Third hospitalization, the signs of minor regression of the soft-tissue inflammatory consolidation of the upper right lobe (arrow).

Figure 2

Cytology findings of pulmonary tissue obtained by biopsy led to diagnosis of mucormycosis; after retesting in a mycology reference laboratory the diagnosis was revised to invasive pulmonary mucormycosis based on wide nonseptic hyphae, suggesting filamentous fungi of the order Mucorales. Hematoxylin and eosin staining × 400; marked with arrows.