Chest Imaging

Small cell carcinoma

a neuroendocrine lung neoplasm characterized by rapid growth and early metastases. It is the most aggressive form of lung cancer and has a very strong association with cigarette smoking. It represents approximately 15-20% of all lung cancers. The whole course of the disease is very short and metastases are usually present at initial diagnosis. Hormone production, notably adenocorticotrophic hormone, antiduretic hormone (ADH) and melanocyte-stimulating hormone production is a characteristic feature of this neoplasm. Surgical resection is inefficient but the primary tumour and metastases often respond to chemotherapy. However, the prognosis is extremely poor, survival time being 9-18 months. When the disease is limited to the chest, survival is approximately 25% after 2 years follow-up. Pathologically small cell carcinoma presents most often as a large central mass invading and obstructing the bronchial lumen. This neoplasm is also the most common cause of superior vena cava obstruction. The most common radiological manifestation includes a hilar or perihilar mass associated with massive bilateral mediastinal lymphadenopathy, lobar atelectasis or obstructive pneumonitis. Sometimes small cell carcinoma manifests as a solitary pulmonary nodule. In such a rare situation, the lesion may be resected and the prognosis is better.

PG