Pulmonary mucormycosis presenting as a cavitary lung lesion after recent autologous stem cell transplantation

SESSION TITLE: Chest Infections Case Report Posters 2 SESSION TYPE: Case Report Posters PRESENTED ON: 10/09/2023 12:00 pm - 12:45 pm INTRODUCTION: Pulmonary mucormycosis is an aggressive opportunistic fungal infection that has a particular predilection for patients with hematological malignancies, as well as recipients of solid organ or stem cell transplants. CASE PRESENTATION: A 66-year-old male with a history of diffuse large B cell lymphoma and autologous stem cell transplantation within the last 30 days was admitted for exertional dyspnea on minimal activity since 1 week, associated with a nonproductive cough. Blood pressure was 135/81 mmHg, heart rate 85 beats/min, respiratory rate 18 breaths/min, temperature 98.8 °F, oxygen saturation 99% on room air. Physical examination was notable for wasting, while lungs were clear to auscultation bilaterally. Leukocyte count was 8 K/uL, hemoglobin was 9.3 g/dL, and platelet count was 226 K/ uL. Chest X ray revealed a new rounded opacity in the right lung, and follow up computed tomography angiography scan revealed a right upper lobe cavitary lesion measuring 3.5 centimeters with adjacent micro nodularity (Figure 1). The patient was started on broad spectrum intravenous antibiotics and voriconazole. An extensive infectious workup for viral, bacterial, and fungal organisms including bronchoalveolar lavage failed to identify any causative organisms. A percutaneous biopsy of the lesion was performed, which returned positive for mucormycetes on fungal staining. Intravenous liposomal amphotericin B was started immediately. Further survey including ophthalmological examination, magnetic resonance imaging of the brain, and computed tomography scan of the abdomen/pelvis was negative for dissemination. The patient was urgently transferred to a more specialized center, where he underwent right upper lobectomy. He was continued on posaconazole for 12 weeks afterwards, with no evidence of relapsing infection after completion of treatment. DISCUSSION: Mucormycosis refers to a spectrum of aggressive infections caused by angio invasive fungi of the Mucorales order. Nearly all infections occur in immunocompromised hosts, and pulmonary infections have been linked to hematological malignancies, as well as solid organ and stem cell transplantation. The usual presentation includes fever, malaise, cough/ hemoptysis, dyspnea, and some degree of chest pain(1). While pulmonary mucormycosis is recognized as an opportunistic infection occurring in the late post engraftment period (> 90 days), our patient presented early within 30 days of autologous stem cell transplantation. Radiographic findings also differed from the classically described appearances of consolidation, ground glass opacities, presence of halo or reverse halo signs, masses, or multiple nodules(2). There have been previous reports of Mucormycosis presenting as a cavitary lung lesion(3). While definite diagnosis requires histopathological evidence, a high index of suspicion should be maintained in appropriate clinical settings. Prompt administration of amphotericin B and aggressive surgical control is usually necessary as infections have a high rate of morbidity and mortality. Isavuconazole and posaconazole are available as options for step down or salvage therapy. CONCLUSIONS: Pulmonary mucormycosis can present early after autologous stem cell transplant as a cavitary lung lesion. Clinicians should maintain a high index of suspicion in immunocompromised populations, as infections are associated with high rates of morbidity and mortality. REFERENCE #1: Steinbrink JM, Miceli MH. Mucormycosis. Infect Dis Clin North Am. 2021 Jun;35(2):435–52. REFERENCE #2: Agrawal R, Yeldandi A, Savas H, Parekh ND, Lombardi PJ, Hart EM. Pulmonary Mucormycosis: Risk Factors, Radiologic Findings, and Pathologic Correlation. RadioGraphics. 2020 May;40(3):656–66. REFERENCE #3: Hammer MM, Madan R, Hatabu H. Pulmonary Mucormycosis: Radiologic Features at Presentation and Over Time. Am J Roentgenol. 2018 Apr;210(4):742–7. DISCLOSURES: No relevant relationships by Ibrahim Ahmed No relevant relationships by Mohammad Ahmed No relevant relationships by Khizar Hamid No relevant relationships by Jiannan Huang