Approach to Intrathoracic Lesions in areas with high prevalence of Histoplasmosis and Sarcoidosis

Differential diagnoses of patients presenting with lung lesions and/or mediastinal lymphadenopathy are primary malignancy, lymphoma, germ cell tumors, metastatic disease, granulomatous lesions, fungal infections such as histoplasmosis, hamartomas, and other benign neoplasm. Despite being a significant and frequent problem, there are few management guidelines recommending the approach to these lesions. Large size and positron emission tomography (PET) positivity of benign lesion is a common finding in areas with high prevalence of histoplasmosis and sarcoidosis. The current guidelines do not specifically address these problems. So, clinicians in these areas face a dilemma on deciding aggressiveness of diagnostic tests. Current diagnostic modalities including serology, imaging, bronchoscopy, etc. have limitations on classifying these lesions into benign vs. malignant. This exposes patients to multiple invasive procedures including surgical biopsy that might be unnecessary in many cases. In this review article, we have analyzed the role of various diagnostic modalities in these patients and proposed a clinico-radiological approach based on current literature. We believe this approach will lead to a decrease in health care costs by limiting the number of invasive diagnostic procedures and may also decrease morbidity and mortality associated with invasive procedures. INTRODUCTION Patients presenting with lung lesions and/or mediastinal lymphadenopathy are common problems for pulmonologists and thoracic surgeons. Differential diagnoses of these lesions are primary malignancy, lymphoma, germ cell tumors, metastatic disease, granulomatous lesions, and fungal infections such as