The Value of a Negative Pleural Fluid Cytology and Biopsy in Diagnosing Malignant Pulmonary Lesions

Over 2 million patients developed lung cancer in 2018, and lung malignancy is responsible for an estimated 1.8 million deaths worldwide. Lung cancer diagnosis usually occurs after suspicious symptoms or incidental radiologic findings on chest imaging when the cancer is probably in an advanced stage. Therefore, initial evaluation, diagnosis, staging, and prompt treatment of lung cancer are required to improve pulmonary malignancies' morbidity and mortality rate. Unfortunately, the size of the tumor, the time of imaging, the quality and quantity of pleural fluid, and pleural biopsy all contribute to diagnostic difficulties in evaluating a lung lesion, leaving even the most astute clinician occasionally perplexed. We discuss a case of a female with lung cancer whose diagnosis was challenging because of a negative pleural biopsy, despite initial radiographic imaging suggesting a lung lesion.