Self Assessment Answers

Discussion Bronchioloalveolar carcinoma is one of the four recognised subtypes of lung adenocarcinoma. The dramatical increase in the incidence of lung adenocarcinoma in the last decade, being in some series the most frequent histological type among all lung malignancies, seems to be mostly due to the raising incidence of bronchioloalveolar carcinoma. Its distinctive pathological feature is growth along alveolar septae without distortion of pulmonary interstitium. Three histopathological subtypes have been described: mucinous, nonmucinous, and sclerotic. Prior pulmonary lesions, some professional exposures, cigarette smoking, and even a viral agent have been proposed as risk factors for developing bronchioloalveolar carcinoma. Males and females are equally aVected. Patients may be asymptomatic in up to half of cases. Clinical symptoms include cough, haemoptysis, chest pain, dyspnoea, and weight loss. Two characteristic features, both present in the case under discussion, are large volume bronchorrhoea and refractory hypoxaemia caused by intrapulmonary shunting. Radiographic patterns include solitary nodules or masses, localised or diVuse consolidation, and diVuse nodules. In diVerential diagnosis, benign and malignant neoplasms (including metastatic disease), lobar pneumonia, congestive heart failure, alveolar haemorrhage, and alveolar proteinosis must be considered. Prognosis is usually poor, and it has been correlated with the presence or absence of symptoms, tumour extension, and histological type. The clincal course of this patient was rapidly fatal, and she died on the 11th hospital day after two episodes of massive haemoptysis. Necropsy confirmed the diagnosis and excluded any other primary neoplasm. This was an important finding, as several adenocarcinomas may show pulmonary metastases with histological pictures indistinguishable from primary bronchioloalveolar carcinoma.