A Rare Mycobacterial Infection Presenting as Worsening Cavitary Lung Lesions

SINGLE CAVITARY LUNG LESION IN A HEALTHY YOUNG MALE

The present study investigates the diagnostic efficiency of apparent diffusion coefficient (ADC) values in differentiating between malignant and benign cavitary lesions on diffusion-weighted magnetic resonance imaging (DWI). This prospective study included 45 consecutive patients identified with a cavitary lung lesion with a wall thickness of ≥5mm on thoracic computed tomography in our clinic between 2020 and 2022, and who underwent thoracic DWI within 1 week of their original computed tomography. ADC measurements were made on DWI by drawing a region of interest manually from the cavity wall, away from the lung parenchyma in the axial section where the lesion was best demonstrated. The patients were then classified into benign and malignant groups based on the pathology or clinico-radiologic follow-up. The sample included 29 (64.4%) male and 16 (35.6%) female patients, with a mean age of 59.06±17.3 years. Included in the study were 1 patient with 3 and 3 patients with 2 cavitary lesions each, with a total for the sample of 50 cavitary lesions. There were 23 (46%) malignant and 27 (54%) benign cavitary lung lesions. The mean ADC value (×10 -3 mm 2 /s) of the malignant and benign cavitary lesions was 0.977±0.522 (0.511 to 2.872) and 1.383±0.370 (0.930 to 2.213), respectively. The findings were statistically significant using an independent samples t test ( P =0.002). The mean wall thickness of the malignant and benign lesions was 12.47±5.51mm (5 to 25mm) and 10.11±4.65mm (5 to 22mm), respectively. Although malignant cavities had a higher mean wall thickness than benign cavities, the difference was statistically insignificant ( P =0.104). A significant difference was identified between the ADC values measured in DWI of the malignant and benign cavitary lung lesions. DWI, a noninvasive and rapid imaging method, can provide useful information for the differential diagnosis of cavitary lesions and can minimize unnecessary biopsies.

To demonstrate clinical features and outcomes in patients with cavitary lung lesions and COVID-19 associated pneumonia. A retrospective analysis of electronic medical records of 8261 patients with COVID-19 was performed. We selected 40 patients meeting the inclusion criteria. Sex, age, hospital-stay, lung tissue lesion, comorbidities, treatment, methods of respiratory support, complications and outcomes were evaluated. Cavitary lung lesions were more common in men (67.5%). Age of patients ranged from 28 to 88 (mean 64.9±13.7) years. Hospital-stay in patients with cavitary lung lesions was 9-58 (median 27.5) days. There were 18 complications in 14 (35%) patients. Pneumothorax, isolated pneumomediastinum, pleural empyema, hemoptysis and sigmoid colon perforation were considered as complications of cavitary lung lesions. Nine (22.5%) patients died (5 of them with complications). Three patients died after surgical treatment. Long-term results were analyzed in 8 (25.8%) patients. Patients were followed-up for 3 months after discharge. Shrinkage of lesions occurred after 7-60 (mean 23) days, and complete obliteration of cavities came after 32 (range 14-90) days. Cavitary lung lesions are a rare complication of COVID-19 pneumonia. There was no significant correlation of complications with age, sex, therapy, volume of lung lesions and non-invasive ventilation (NIV). Despite more common fatal outcomes in older patients undergoing NIV, the last one was prescribed exclusively due to disease progression and respiratory failure. Further research on this problem is necessary to identify possible risk factors of cavitary lung lesions.

Pulmonary cystic and cavitary lesions caused by diverse etiologies are commonly encountered in chest imaging. The terms "cyst" and "cavity" are used to describe air-filled regions in the center of a nodule or consolidation of the lung. To date, only radiologic aspects of these lesions have been addressed. The morphologies of pulmonary cystic and cavitary lesions exhibit a broad spectrum, ranging from benign to malignant pulmonary diseases of acquired or congenital origin, including variable infectious diseases. In this review, we summarized the differential diagnosis of pathological entities to provide pathologists and radiologists with an overview of the diseases most commonly associated with pulmonary cystic and cavitary lesions in adults and children. The results showed slightly different patterns in the distribution of the diseases in the two groups. The most common causes of cavitary lesions include malignancy and infection in adults, and congenital malformation in children. Therefore, identification of pathologic entities correlating with the radiologic findings, clinical course, and location of the lesion is important in the evaluation of cystic and cavitary lung lesions in order to avoid unnecessary surgical procedures or delayed treatment.

Cavitary lung lesions pose a formidable diagnostic challenge due to their multifaceted etiologies. While tuberculosis and other prevalent pathogens typically dominate discussions, instances of community-acquired Pseudomonas aeruginosa (P. aeruginosa) pneumonia leading to cavitation in immunocompetent individuals remain exceptionally rare. Herein, we present a compelling case of such pneumonia in a 61-year-old man with a past medical history of hypertension and coronary artery disease who presented with cough, chest pain, and subjective fever. Chest imaging revealed cavitary lung lesions, which is atypical for community-acquired pneumonia (CAP). Initial workup excluded common CAP pathogens, following which bronchoscopy with bronchoalveolar lavage (BAL) definitively diagnosed P. aeruginosa, prompting targeted antibiotic therapy. Treatment led to clinical and radiographic improvement. P. aeruginosa rarely causes CAP, especially in immunocompetent patients, and cavitary lesions further complicate diagnosis. This case highlights the importance of considering P. aeruginosa in CAP with unusual features and emphasizes the utility of bronchoscopy with BAL for diagnosis and guiding management.

Cavitary lung lesion as sequelae of mild COVID-19 in a patient with HIV.

AN UNUSUAL PRESENTATION OF MALIGNANCY

TO CAVITATE OR NOT TO CAVITATE: ATYPICAL PRESENTATION OF A COMMON PATHOGEN

A 43-year-old female patient is being followed up with a diagnosis of rheumatoid arthritis. She presented with ulcerated lesions on the lower extremity, diffuse subcutaneous nodules, dyspnea, hemoptysis, and fever. Cavitary lesions were detected on the chest X-ray and thoracic computed tomography (Figure 1). The biopsy sample taken from the lesion in the lung was interpreted as “tumor necrosis”. The biopsy sample from subcutaneous nodules was interpreted as ”T-cell/histiocyte-rich large B-cell lymphoma”. There may be some similarities between various lung cavitary lesions, knowledge of the possible causes and a systematic approach will help to narrow down the huge list of differential diagnoses. CAVITY mnemonics can be used for diseases that may cause cavitary lesions in the lung (Table 1) (1). Pulmonary cysts are mimics of emphysema, cystic bronchiectasis, and bullous lung cavitary lesions, and before diagnosing a cavitary lesion, it should be ensured that it is not one of these mimics.

A case of a cavitary lung lesion in the right middle lobe of a 34-year-old woman who presented with hemoptysis is presented. The patient had a 2-year history of Wegener granulomatosis that had been treated with cyclophosphamide and corticosteroids. Although the patient gradually achieved remission of her disease, she developed new pulmonary symptoms and a cavitary lesion in her right lung. Further workup revealed elevated C- and P-ANCA titers. Following partial resection of her right lung, she was found to have an aspergilloma and no evidence of active Wegener granulomatosis. Pulmonary aspergillosis was felt to be the cause of both the hemoptysis and the cavitary lesion. We postulate that C-ANCA and P-ANCA were falsely positive in this case. Although rare, false positive C-ANCA and P-ANCA have been reported in pulmonary fungal infections.

Rhizopus homothallicus is an emerging pathogen that causes pulmonary mucormycosis. We report a case of pneumonia caused by R. homothallicus in a 54-year-old type 2 diabetic patient. The organism was isolated from bronchoalveolar lavage fluid and preliminarily identified by fungal morphology and finally by sequencing of the internal transcribed spacer region. Mucormycosis may be associated with cavitary lung lesions against a backdrop of poorly controlled diabetes or other immunosuppressed states. Pulmonary mucormycosis may have variable clinical and radiological presentations. Therefore, strong clinical suspicion and prompt management can address the high fatality associated with the disease.

An unusual cause of spontaneous pneumothorax: Post-COVID-19 pulmonary fibrosis

Nontuberculous mycobacterium (NTM) species are mycobacterial species other than those belonging to the Mycobacterium tuberculosis complex and M. leprae. NTM are generally free-living organisms that are ubiquitous in the environment. Pulmonary disease, especially in older persons with and without underlying lung disease, is caused primarily by M. avium complex (MAC) and M. kansasii. The symptoms and signs of MAC lung disease are variable and not specific, but include cough, malaise, weakness, dyspnoea, chest discomfort and occasionally hemoptoe. Two major clinical presentations include disease in those with underlying lung disease, primarily white, middle-aged or elderly men - often alcoholics and/or smokers with underlying chronic obstructive lung disease, patients in whom MAC develops in areas of prior bronchiectasis, and patients with cystic fibrosis; and those without known underlying lung disease, including non-smoking women over age 50 who have interstitial patterns on chest radiography. M. kansasii infections are endemic in cities with infected tap water. Symptoms of the M. kansasii lung disease resemble to tuberculosis. M. abszessus is the most pathogenic rapid growing Mycobacterium which causes pulmonary infection. The American Thoracic Society and Infectious Disease Society of America's diagnostic criteria for nontuberculous mycobacterial pulmonary infections include both imaging studies consistent with pulmonary disease and recurrent isolation of mycobacteria from sputum or isolated from at least one bronchial wash in a symptomatic patient. For treatment of MAC lung disease we recommend depending on severity and susceptibility testing a three to four drug treatment with a macrolide, rifampicin and ethambutol and for M. kansasii a treatment with Isoniazid, rifampicin and ethambutol. Surgical management only plays a role in rare and special cases. Treatment should be continued until sputum cultures are consecutively negative for at least one year.

Pulmonary cavitary lesions with pneumothorax are very common in chest imaging and usually pose diagnostic challenge to clinicians Pneumothorax with a cavitary lesion is a rare occurrence in primary and metastatic lung cancer. A 40-year-old male presented with cough with whitish expectoration, right loin pain, loss of weight and appetite for 3 months and difficulty in breathing for 2 days. Chest x-ray was suggestive of right-side pneumothorax with bilateral nodular opacities in all zones. Contrast-enhanced computed tomography (CECT) thorax and abdomen revealed a non-homogenous large mass in the right kidney with hydronephrotic changes with cavitary lesions in bilateral lungs. Urine cytology was suggestive of urothelial carcinoma. Thus, a diagnosis of urothelial cancer with cavitating metastasis leading to secondary spontaneous pneumothorax was made. Herein, we aim to highlight that cavitating metastasis should be considered in a case of pneumothorax with bilateral lung nodules.

Coronavirus Disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus type 2, which is characterized by high infectiousness and diverse clinical manifestations. They are more likely to become critical in people who have underlying diseases or are immunocompromised. In the daunting task of treating patients with COVID-19, those with comorbid fungal infections are susceptible to underdiagnosis or misdiagnosis, which can ultimately lead to increased morbidity and mortality in this group of patients. We report a case of intrapulmonary cavitary lesions after COVID-19, which was eventually diagnosed as pulmonary aspergillosis (PA) by metagenomic Next Generation Sequencing (mNGS) to improve our understanding of the disease. Appropriate laboratory tests, chest computed tomography (CT), mNGS, and serologic tests were performed for diagnosis. Laboratory tests showed Glactomannan (GM) of 1.41, multiple cavitary lesions in both lungs on chest CT and the presence of aspergillus infection was confirmed by sputum sent for mNGS. In the case of cavitary lesions after COVID-19, we should be alert to the possibility of combined fungi and should promptly perform mNGS to clarify whether there is a combination of specific pathogenic fungal infections.