Imaging findings of expansile lesions of the thymus.

The purpose of this article is to review the imaging findings of the different expansile lesions of the thymus. Almost 50% of all mediastinal masses are located in the anterior mediastinum. The thymus is the most common site of origin of these masses. Several kinds of lesions can arise from this gland because it derives from the three embryonic germ cell layers. Primary neoplasms of the thymus are thymoma, thymolipomas, carcinoma, carcinoid, primary germ cell tumors, and lymphoma. The latter can also involve the organ in a secondary fashion. Other lesions that cause thymic enlargement and that can be confused with neoplasia are thymic cysts and thymic hyperplasia. Even though anterior mediastinal masses are first found on conventional radiographs, computed tomography and magnetic resonance are very useful additional studies for assessing the origin and extension of these masses. The basic concepts regarding embryology, anatomy, and histology relevant for the differential diagnosis of an enlarged thymic gland are also described.

Tracheobronchopathia osteochondroplastica: helical CT findings in 4 cases.

Tracheopathia osteochondroplastica is an uncommon abnormality of the cartilaginous tracheal wall, characterized by the presence of osteocartilaginous calcified nodules within the submucosa, with variable degree of diffuse tracheal narrowing. Imaging findings in CT are characterized by the presence of calcified nodular densities protruding into the tracheal lumen, with an abnormally irregular tracheal morphology and often decreased lateral diameter. This can extend to the proximal main stem bronchi. CT is the imaging modality of choice in this entity. The clinical manifestations, as well as the imaging findings, in 4 cases are reviewed.

Association of two respiratory congenital anomalies: tracheal diverticulum and cystic adenomatoid malformation of the lung.

Many associations of congenital anomalies of the respiratory system have been reported, but the combination of tracheal diverticulum and cystic adenomatoid malformation (CCAM) is unique. We present a patient with these two anomalies and analyze their embryological correlation.