The Use of Endobronchial Ultrasound in the Diagnosis of Subacute Pulmonary Histoplasmosis

The evolution of endobronchial ultrasound usage in modern era

Over the past two decades, endobronchial ultrasound (EBUS) has become a crucial tool for diagnosing pulmonary diseases. The most common indication of EBUS usage is the diagnosis and staging of lung cancer. Additionally, there have been significant improvements in the application of convex probe EBUS in line with the increase in experience and knowledge about EBUS and the developments in medicine and technology. To enhance diagnostic accuracy and acquire larger tissue samples, techniques such as cryo-biopsy guided by endobronchial ultrasound (EBUS) and intranodal forceps biopsy have been developed. Additionally, elastography functionality has been integrated into the EBUS application to improve the assessment of targeted lesions. Moreover, its utilization for evaluating and sampling pulmonary vascular structures has expanded. It has also found applications in guiding intratumoral therapy, positioning fiducial markers, and facilitating the drainage of pleural or pericardial effusions. This review aims to provide an overview of the extended applications of convex probe EBUS beyond its conventional uses.

Role of EBUS-TBNA in Non-Neoplastic Mediastinal Lymphadenopathy: Review of Literature

Mediastinal lymphadenopathy is a condition in which one or more mediastinal lymph nodes are enlarged for malignant or benign causes, generally more than 10 mm. For a long time, the only way to approach the mediastinum was surgery, while in last decades endoscopic techniques gained their role in neoplastic diseases. At the present time, EBUS is the technique of choice for studying the mediastinum in the suspicion of cancer, while there are not strong indications in guidelines for the study of benign mediastinal lymphadenopathy. We reviewed the literature, looking for evidence of the role of EBUS in the diagnostics of non-neoplastic mediastinal lymphadenopathy, with special regard for granulomatous disease, both infectious and non-infectious. EBUS is a reliable alternative to surgery in non-neoplastic mediastinal lymphadenopathy, even if more evidence is needed for granulomatous diseases other than tuberculosis and sarcoidosis.

Histoplasmosis

Histoplasmosis is one of the commonest endemic mycoses in the Americas yet is often underdiagnosed and neglected as a public health priority. This review outlines the evolving understanding of its epidemiology and the clinical syndromes of histoplasmosis, in addition to up-to-date diagnostic and treatment guidelines. A focus on histoplasmosis in advanced HIV is included. The challenges pertinent to histoplasmosis management in Latin America, with recommendations made through international expert consensus are discussed.

Mediastinal lymphadenopathy: a practical approach

Introduction: Mediastinal lymphadenopathy is secondary to various benign and malignant etiologies. There is a variation in the underlying cause in different demographic settings. The initial clue to the presence of enlarged mediastinal lymph nodes is through thoracic imaging modalities. Malignancy (Lung cancer, lymphoma, and extrathoracic cancer) and granulomatous conditions (sarcoidosis and tuberculosis) are the most common causes. For a confident diagnosis, the clinician must choose from several available options and integrate the clinical, radiological, and pathology findings. An accurate diagnosis is necessary for optimal management.Areas covered: We performed a search of the PUBMED database to identify relevant articles on the causes, imaging modalities, and interventional modalities to diagnose these conditions. We discuss a practical approach toward the evaluation of a patient with mediastinal lymphadenopathy.Expert opinion: Mediastinal lymphadenopathy is a commonly encountered clinical problem. Treating physicians need to be aware of the clinico-radiological manifestations of the common diagnostic entities. Selecting an appropriate tissue diagnosis modality is crucial, with an intent to use the least invasive technique with good diagnostic yield. Endosonographic modalities (EBUS-TBNA, EUS-FNA, and EUS-B-FNA) have emerged as the cornerstone to most patients' diagnosis. An accurate diagnosis translates into favorable treatment outcomes.

Clinical Usefulness of Fungal Culture of EBUS-TBNA Needle Rinse Fluid and Core Tissue

PURPOSE

The diagnosis of pulmonary fungal infections is challenging due to the difficulty of obtaining sufficient specimens. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) needle rinse fluid has become an emerging diagnostic material. This study evaluated the role of routine fungal culture from EBUS-TBNA needle rinse fluid, in addition to histopathologic examination and fungal culture of EBUS-TBNA core tissue, in the diagnosis of pulmonary fungal infections.

MATERIALS AND METHODS

Among patients who underwent EBUS-TBNA, those with results for at least one of three tests (histopathologic examination, fungal culture of EBUS-TBNA core tissue or needle rinse fluid) were included. Patients with a positive test were divided into two groups (clinical fungal infection and suspected fungal contamination) according to their clinical assessment and therapeutic response to antifungal.

RESULTS

Of 6072 patients, 41 (0.7%) had positive fungal tests and 9 (22%) were diagnosed as clinical fungal infection. Of the 5222 patients who were evaluated using a fungal culture from EBUS-TBNA needle rinse fluid, 35 (0.7%) had positive results. However, only 4 out of 35 (11.4%) were classified as clinical fungal infection. Positive results were determined in 4 of the 68 (5.9%) evaluated by a fungal culture of EBUS-TBNA core tissue, and all were diagnosed as clinical fungal infection.

CONCLUSION

Routine fungal culture of EBUS-TBNA needle rinse fluid is not useful due to the low incidence of fungal infection and high rate of contamination. However, fungal culture of EBUS-TBNA core tissue and needle rinse fluid should be considered in patients with clinically suspected fungal infection.

Role of Convex Probe Endobronchial Ultrasound in the Diagnosis and Treatment of Nonmalignant Diseases

Here we present a comprehensive review of the literature concerning the utility of convex probe endobronchial ultrasound (CP-EBUS) in the diagnosis and treatment of nonmalignant conditions and discuss the associated complications. CP-EBUS has been conventionally used for the staging of lung cancer and sampling of mediastinal and hilar nodes. However, its application is not limited to malignant conditions, and it is gaining acceptance as a diagnostic modality of choice for nonmalignant conditions such as tuberculosis, sarcoidosis, pulmonary embolism, thyroid lesions, and cysts. Moreover, its therapeutic value allows for extended applications such as mediastinal and thyroid cyst drainage, fiducial marker placement for radiation therapy, and transbronchial needle injection. The noninvasiveness, low complication rate, high diagnostic yield, and satisfactory sensitivity and specificity values are the main attributes that lend credence to the use of CP-EBUS as a standalone primary diagnostic and therapeutic tool in pulmonary medicine in the foreseeable future.

Clinical Perspectives in the Diagnosis and Management of Histoplasmosis

With increasing numbers of travelers and immunocompromised patients, histoplasmosis, caused by the dimorphic fungus Histoplasma capsulatum, has become a disease of national extent. The clinical spectrum of histoplasmosis is very wide, in terms of disease cadence, onset, distribution, and severity. A multipronged approach is recommended for diagnosis. Manifestations that are always treated include moderate to severe acute pulmonary histoplasmosis, disseminated disease, and histoplasmosis in immunocompromised individuals. Amphotericin B is the drug of choice for moderate to severe and disseminated presentations, whereas itraconazole is appropriate for mild disease and as step-down therapy.

Pulmonary mucormycosis diagnosed by convex probe endobronchial ultrasound-guided fine needle aspiration of cavity wall

Pulmonary mucormycosis is an opportunistic fungal infection in immunocompromised individuals. It is difficult to diagnose as it requires tissue biopsy, and generally these patients are unfit to undergo invasive lung biopsies. We describe a novel technique in a case with uncontrolled diabetes mellitus with nonresolving pulmonary cavitary disease where convex probe endobronchial ultrasound (EBUS)-guided aspiration of lung cavity wall showed classical histopathological picture establishing the diagnosis of mucorale infection. EBUS being real-time, minimally invasive technique with minimal risk of complications, led to early diagnosis, and prompt treatment. This appears to be a novel diagnostic modality in pulmonary mucormycosis with minimal complications as compared with other biopsy methods with very high complication risk.

Usefulness of lymphoid granulomatous inflammation culture obtained by endobronchial ultrasound-guided transbronchial needle aspiration in a fungal endemic area

Background and Objectives:

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is the procedure of choice for the evaluation of mediastinal/hilar lymph node enlargements. Granulomatous inflammation of the mediastinal/hilar lymph nodes is often identified on routine histology. In addition, mediastinal lymphadenopathy may be present with undiagnosed infection. We sought to determine the usefulness of routine cultures and histology for infectious etiologies in a fungal endemic area when granulomatous inflammation is identified.

Materials and Methods:

We identified 56 of 210 patients with granulomatous inflammation on EBUS-TBNA biopsies from October 2012 through October 2014. An onsite cytologist evaluated all biopsies and an additional TBNA pass for microbiologic stains and cultures were obtained in those with granulomatous inflammation.

Results:

Of the 56 patients with granulomatous inflammation, 20 patients had caseating (necrotizing) granulomas while noncaseating (nonnecrotizing) granulomas were detected in 36 of the remainder patients. In patients with caseating granulomas, fungal elements were identified in 6 of 20 (30%) patients (histoplasma; N = 5, blastomyces; N = 1) on Grocott methenamine silver (GMS) stain. Lymph node cultures identified 3 of 20 (20%) patients as being positive for Mycobacterium tuberculosis (N = 1), Histoplasma capsulatum (N = 1), and Blastomyces dermatitidis (N = 1). Among patients with noncaseating granulomas, only 2 out of 36 (5%) were positive for fungal elements on GMS stain, identified as Histoplasma, although the lymph node cultures remained negative.

Conclusion:

The incidence of granulomatous inflammation of mediastinal lymph nodes was 26.6% in our series. Of these patients, noncaseating granulomas were more common (64% vs. 36%). Infectious organisms, fungal or acid-fast bacilli (AFB), on either staining or lymph node culture were rarely identified in noncaseating granulomas, 5% and none, respectively. Caseating granulomas were more commonly associated with positive lymph node fungal stain and culture, 35% and 15%, respectively. In a fungal endemic area, lymph node staining and culture can be considered in cases with caseating granulomatous inflammation, if known at the time of biopsy.