Calcified mediastinal bronchogenic cysts.

Abstract

THE DIFFERENTIAL diagnosis of mediastinal lesions is difficult because of the large number of anatomic structures contained within this small space and the homogeneity of tissue densities. Although numerous diagnostic technics may be employed, the location of the tumor still remains the most critical factor in arriving at the correct diagnosis. One of the few additional helpful features is the presence of calcification. Although numerous reports in the literature have been concerned with bronchogenic cysts, it was not until recently that Cornell (1) described milk of calcium layering within the lumen of two such cysts. This communication is the first report of the demonstration of radiographically detectable calcium within the walls of two bronchogenic cysts. Case Reports Case I: In this 43-year-old man a mediastinal mass was found on a routine chest film. Aside from episodic asthma of many years duration, the patient was asymptomatic. The findings on physical examination, laboratory investigation, bronchoscopy, and mediastinoscopy were normal. Radiographic studies (Fig. 1) showed a middle mediastinal mass, 8.5 cm in diameter, in the subcarinal region to the right of the midline, indenting the anterior portion of the esophagus. A thin, curvilinear calcification 5 cm in length was visible in the outer and inferior aspect of the mass. This calcification did not change shape or position with change in position of the patient, indicating that it was not milk of calcium. At exploratory thoracotomy the lesion was removed. Histologic examination revealed a bronchogenic cyst with a fibrous tissue wall lined by ciliated columnar epithelium. No cartilage was present. Calcium was noted within the wall of the cyst. CASE II: During a work-up for migratory joint pain, a mediastinal lesion was discovered on a routine chest film in this 23-year-old male. There were no respiratory symptoms except for a mild dry cough. Radiographic studies (Fig. 2) showed a middle mediastinal mass, 5 cm in diameter, in the subcarinal region, projecting to the right and indenting the right side of the esophagus. A thin, curvilinear calcification 3 cm in length was best seen in the posterosuperior portion of the mass on the ovcrpenetrated oblique film. At exploratory thoracotomy the lesion was removed. Histologic examination showed the wall of the cyst to be lined by ciliated columnar epithelium. It contained mucous glands and smooth muscle, but no cartilage was demonstrated on the available sections. Calcification was noted in the fibromuscular tissue of the cyst wall, beneath the epithelium. Discussion Mediastinal bronchogenic cysts are congenital in origin and result from abnormal budding or branching of the tracheobronchial tree (2). The majority of them are located in the vicinity of the trachea or main bronchi, although some may be far removed from this area (3, 5).