Small cell lung carcinoma (SCLC) is the most aggressive form of lung cancer, accounting for approximately 15% of new lung cancer diagnoses and 25% of lung cancer deaths each year.^{1, 2} SCLC more commonly occurs in men than in women. There is a strong association with tobacco use and SCLC.³ Risk of developing SCLC increases with longer duration and intensity of smoking; although, rarely, cases have been reported in people lacking smoking history.^{4, 5}

The clinical course of SCLC is characterized by a rapid doubling time and early, wide-spread metastases, as seen in our study patient. Around two-thirds of patients will have extensive-stage disease at the time of diagnosis.6 Onset of symptoms is swift and includes cough, wheezing, dyspnea, and hemoptysis caused by local intrapulmonary tumor growth. Other indications of SCLC are presenting with post-obstructive pneumonia, symptoms due to intrathoracic spread to the chest wall, superior vena cava, or esophagus, recurrent nerve, pain, fatigue, anorexia, paraneoplastic syndromes, and neurological complaints caused by metastasis. Metastatic spread, which may be present at time of initial diagnosis, frequently involve liver, bone, and brain.

SCLC cases are likely to harbor inactivating mutations in TP53 and RB1.^7-9

The prognosis for SCLC is poor with the 5-year survival rate at less than 10%.^{1, 10} For the treatment of SCLC, platinum-based chemotherapy without surgery is typically the mainstay, as the disease is considered advanced stage. However, despite therapy and high initial treatment response, relapse and progression of disease is common.^{11, 12}

Because of the non-operative treatment approach to SCLC, proper identification at time of rapid on-site evaluation will stop the bronchoscopy procedure. This is unlike cases of non-small lung carcinoma, where staging is instrumental in treatment decisions. Studies have demonstrated endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-FNA), particularly when rapid on-site evaluation (ROSE) is employed at the time of the procedure, to show high sensitivity, positive predictive value, and diagnostic accuracy (greater than 90%); the negative predictive value of EBUS-FNA, however, has been shown to be lower due several potential factors, including limited time for interpretation, limited sampling, and poor staining quality.^13-17