Mangin, W W

Abstract Rationale Fungal infections are a significant cause of morbidity in lung transplant recipients. Infections caused by non-Aspergillus species (spp.) fungi, such as Alternaria, Cladosporium, Fusarium, Lomentospora, Mucorales, and Scedosporium, among others, occur infrequently, but recognized cases are increasing. There is a paucity of data assessing post-transplant outcomes following pre-transplant fungal colonization with these non-Aspergillus spp. fungal organisms. Methods We retrospectively reviewed all adult (>18 years) patients who underwent bilateral lung transplantation at either Mayo Clinic Rochester and Mayo Clinic Jacksonville between 01/01/2016 through 12/31/2024, comparing those with pre-transplant fungal colonization to those without fungal colonization. Fungal colonization was defined as positive respiratory culture in either sputum, tracheal aspirate, bronchial brush, bronchoalveolar lavage (BAL) fluid, or swab of explanted lung in asymptomatic patients without radiological or endobronchial evidence of infection. Patients who underwent single lung transplantation, multi-organ transplantation, and those who had previously undergone organ transplantation were excluded from the study. Our primary outcome was severe post-transplant fungal infection, which we defined as proven or probable invasive fungal infection (based on EORTC/MSG criteria), that required hospitalization or additional procedural intervention. Baseline characteristics were summarized using medians with interquartile ranges or counts with percentages, group balance was assessed using standardized mean differences, and associations with post-transplant fungal infection and mortality were evaluated using unadjusted risk ratios (RR) with 95% confidence intervals. Results Of the 449 lung transplant recipients who were included in analysis, a total of 83 patients (18.5%) had pre-transplant fungal colonization, 45 patients (10.0%) with Aspergillus spp. and 38 patients (8.5%) with non-Aspergillus fungi. Compared to those without pre-transplant fungal colonization (n = 366), those with fungal colonization differed significantly in age, gender, body mass index (BMI), Cytomegalovirus (CMV) mismatch status, and transplant indication. The pre-transplant fungal colonization cohort had 4 patients (4.8%) develop any severe fungal infection post-transplant (2 Aspergillus spp. and 2 non-Aspergillus spp.). Pre-transplant fungal colonization was not associated with severe post-transplant fungal infection [RR 1.36 (0.45-4.06)] or with severe post-transplant Aspergillus spp. infection specifically [RR 0.80 (0.18-3.55)]. Unadjusted mortality was also not statistically significant [RR 0.74 (0.47-1.17)]. Conclusions In our cohort of bilateral lung transplant recipients, pre-transplant fungal colonization was not associated with severe post-transplant invasive fungal infection. Although limited by the retrospective nature of the study, the results provide supportive evidence that pre-transplant fungal colonization should not be a precluding factor for undergoing lung transplantation. This abstract is funded by: None

Abstract Most malignant effusions are mononuclear predominant, with only 16-20% being neutrophilic. Neutrophilic predominance should raise suspicion for secondary inflammatory process, particularly empyema. In absence of infection, elevated neutrophils can be a sign of tumor necrosis or tumor lysis. In malignant pleural effusions, markers such as low glucose, low pH, and high LDH may indicate a high tumor burden and are markers of poor outcomes. 64-year-old male with past medical history of metastatic mucinous lung adenocarcinoma status post diagnostic right lower lobe wedge resection and recurrent bilateral malignant pleural effusions, presented to outpatient clinic for therapeutic right-sided thoracentesis. 900 mL of viscus green-brown pleural fluid was removed, and initial fluid studies revealed a neutrophil-predominant exudate with 45,045 total nucleated cells (TNCs) and pH of 7.01. Given concern for infection the patient was admitted, and a right-sided 14 French pigtail pleural catheter was placed. Left-sided thoracentesis was also performed, with pleural fluid studies consistent with a lymphocytic exudate. Vitals on admission were all within normal limits and white blood cell count was 8.9. Chest computed tomography (CT) scan showed extensive bilateral lymphangitic metastases scattered throughout both lungs and bilateral hydropneumothoraces with evidence of a left-sided pleural rind. Infectious workup, including pleural fluid cultures and broad-range bacterial polymerase chain reaction (PCR) were all negative. Cytology of both left and right pleural fluid revealed malignant adenocarcinoma with a substantial amount of necrosis. Patient was discharged home on oral antibiotics with plan to follow up as outpatient for possible tunneled pleural catheter placement. Post-discharge, patient continued to receive intermittent therapeutic thoracenteses. Subsequently readmitted, again with concerns for empyema, bilateral tunneled pleural catheters were placed after infectious workup was again unrevealing. At one month follow up, he reported drainage of 300-500 mL of pleural fluid with alternating daily drainages without complication. Differentiating neutrophilic malignant pleural effusions from empyema is clinically difficult and can lead to delay in definitive pleural treatments. Although it is important to rule out infection, malignancy should remain on one’s differential diagnosis, particularly if the remainder of the patient’s history and presentation are inconsistent with an infectious etiology. This abstract is funded by: None

Abstract Tracheal tumors are uncommon, comprising only 0.2% of respiratory tract malignancies, with the majority of these being squamous cell carcinoma and adenoid cystic carcinoma. Tracheal chondrosarcomas are a rare cause, with only thirty-four cases described in literature between 1959 and 2020. Although often asymptomatic, nonspecific symptoms including dyspnea, nonproductive cough, and wheezing contribute towards misdiagnosis with diseases such as asthma or chronic obstructive pulmonary disease (COPD). Delay in diagnosis can potentially lead to complete tracheal obstruction and airway compromise. Treatment of choice is surgical resection, with overall 10-year survival to be around 95%. Although recurrence rates are minimal when treated with open surgical resection with negative margins, post-surgical surveillance is recommended. Use of extracorporeal membrane oxygenation (ECMO) during surgery offers an alternative to endotracheal intubation, potentially making complete tumor resection easier. A 56-year-old male never smoker with past medical history of hereditary hemochromatosis, requiring phlebotomy, severe obstructive sleep apnea status post right upper airway nerve stimulator placement, and a history of left vocal cord granuloma that presented to an outpatient pulmonology clinic for chronic cough and exertional dyspnea. Initially, the patient was started on a proton pump inhibitor and nasal corticosteroid, without improvement in symptoms. He subsequently underwent pulmonary function testing, which showed flow volume loop suspicious for variable extrathoracic airway obstruction. Chest computed tomography (CT) scan was significant for a 2.2 cm soft tissue lesion in the left upper mediastinum with protrusion through the tracheal wall. PET scan did not show significant FDG avidity. A 1.5 centimeters lesion situated about 5 centimeters above the carina was found on rigid bronchoscopy and biopsies were negative for malignancy. Patient subsequently underwent video-assisted thoracoscopic surgery (VATS) robotic-assisted tracheal resection on Veno-venous ECMO. Final pathology was consistent with G1 chondrosarcoma, with negative margins. On follow up, patient's respiratory symptoms have resolved and periodic surveillance with repeat chest CTs is planned. This unique case offers an important reminder of a potential cause of upper airway obstruction, not only highlighting the potential of pulmonary function testing to aid in early detection, but also the successful use of ECMO in surgical resection.