An exercise in radiologic-pathologic correlation.

Abstract

There are only a few localized pulmonary abnormalities which by their radiographic appearance and location suggest specific pathologic entities. More often the radiologist is faced with a complex of puzzling chest densities, a nonspecific clinical picture, and confusing laboratory data which make a diagnosis of the pathologic problem almost impossible except by thoracotomy and tissue analysis. The case presented this month, however, does not fit this pattern but affords the radiologist the rare opportunity to render a precise and practically histologic diagnosis. Radiology The initial radiographs of the chest (Fig. 1) show a well defined parenchymal abnormality involving the left lower lobe. The density is relatively homogeneous, and there is no evidence of pleural fluid or associated adenopathy. The x-ray appearance is thus consistent with pneumonia. Follow-up chest examination one week later demonstrated partial resolution. Approximately six months later, a repeat chest examination (Fig. 2), performed because of anterior chest pain and cough, demonstrated cystic changes in the same location. No fluid levels are noted, however, and again there is no evidence of pleural effusion, adenopathy, additional pulmonary lesions, or contiguous vertebral abnormality. The persistence of the findings associated with recurrent symptoms and cystic changes suggests a more chronic pulmonary process such as bronchiectasis. Selective bronchography reveals nonfilling of the terminal portions of the major bronchi to the abnormal area (Fig. 3) as well as slight lateral displacement of the adjacent normal bronchial segments. The lack of filling in the cystic areas suggests the probability of an abnormal pulmonary segment, specifically an intralobar bronchopulmonary sequestration which must have had a small communication with the bronchial tree (to account for air-filled cysts) after breakdown secondary to infection. Since these embryologic defects are usually supplied by one or more aberrant arteries, percutaneous transfemoral thoracic aortography was performed as the next diagnostic procedure. It discloses a single aberrant vessel arising between the intercostal arteries at T-9 and T-10 on the left (Fig. 4). Selective catheterization shows the vessel to be of larger caliber than the intercostal arteries. Its course is dorsolateral with mild stretching and arborization around the periphery of the cysts (Fig. 5). Despite adequate arterial filling, venous drainage is not demonstrated satisfactorily. Subtraction films suggested venous drain age to the left atrium through pulmonary veins, which is the usual route in intralobar pulmonary sequestration. Clinical Findings and Analysis The patient is a 19-year-old Negro female who had no pulmonary complaints until the age of eighteen when she experienced an episode of fever, chills, and cough. A chest radiograph at this time showed consolidation of the left lower lobe and she was treated with tetracycline.