Pulmonary aspergilloma with prominent oxalate deposition

Abstract

Some Aspergillus species produce oxalic acid, which reacts with tissue calcium or blood to precipitate calcium oxalate. Oxalate crystals can induce lung and kidney damage. The presence of oxalate crystals can suggest the diagnosis of aspergillosis, even when Aspergillus hyphae are absent on microscopic slides.

CLINICAL IMAGE

A 47-year-old male patient, heavy smoker, presented with hemoptysis and weight loss for the past one month. On admission, his body temperature was 39°C. Chest X-ray showed a well-defined cavitary opacity in the right upper lobe. Laboratory tests revealed a white blood cell count of 17.500/mm³ and CRP levels of 230 mg/L. Based on clinical and imaging findings, the differential diagnoses are as follows: pulmonary abscess, mycobacterium tuberculosis infection, non-tuberculous mycobacterial infection, aspergillosis, and lung cancer.¹ Since sputum samples for acid-fast bacilli were negative, tuberculosis was excluded. Bronchoscopy revealed in the right upper lobe bronchus an inflammatory mucosa with white lesions (Figure 1A). Histological examination of the bronchial biopsy specimen revealed prominent calcium oxalate crystals associated with branching septate hyphae (Figure 1B,C). The culture of bronchoalveolar lavage specimens had identified Aspergillus Flavus. Computed tomography scan demonstrated a large cavity in the right upper lobe measuring 46 × 73 mm, with surrounding infiltration, and an intracavitary nodular lesion (Figure 1D). The final diagnosis was pulmonary aspergilloma due to Aspergillus flavus. After medical treatment with Voriconazole, the patient was planned for right upper lobectomy. Pulmonary oxalosis is a rare pseudotumoral lesion, which is often secondary to an infection by Aspergillus niger and rarely by Aspergillus flavus.²

FIGURE 1. (A) Bronchoscopy revealed in the right upper lobe bronchus an inflammatory mucosa with white lesions and an enlarged spur between the right upper lung bronchus and the intermediate bronchus. (B, C) Histological examination of the biopsy specimen revealed crystals with rosettes arrangements (B, C). Aspergillus hyphae are septate, of fairly uniform thickness and branch dichotomously (B) (Hematoxylin and eosin, magnification × 200). (D) Computed tomography scan revealed a cavity in the right upper lobe measuring 46 × 73 mm, with surrounding infiltration, and an intracavitary nodular lesion.

AUTHOR CONTRIBUTIONS

Dr Faten Limaiem and Dr Hana Blibech prepared, organized, wrote, and edited all aspects of the manuscript. Dr Leila Bouhajja prepared all of the histology figures in the manuscript. Pr Bechir Louzir and Pr Leila Ben Farhat participated in the conception and design of the study, the acquisition of data, analysis and interpretation of the data. All authors contributed equally to preparing the manuscript and participated in the final approval of the manuscript before its submission.

ACKNOWLEDGMENTS

None.

CONFLICT OF INTEREST

None declared.

DATA AVAILABILITY STATEMENT

In accordance with the DFG Guidelines on the Handling of Research Data, we will make all data available upon request.

EHTICAL APPROVAL

All procedures performed were in accordance with the ethical standards. The examination was made in accordance with the approved principles.

CONSENT

Published with written consent of the patient.