Retropharyngeal Space

Case A features a large, oblong fluid collection with an enhancing rim in the retropharyngeal space (RPS) (bilateral but predominantly on the right) from the level of the tonsillar pillar to the level of the thyroid cartilage, which is most consistent with a retropharyngeal abscess. This fluid collection began as a peritonsillar abscess (the round area on the axial image) and extended secondarily into the RPS.

Case B features a large prevertebral hematoma from C4 through T3 with a patent airway. Edema or phlegmon in the retropharyngeal region of the hematoma also is noted on the sagittal image, without frank abscess.

In Case C, a necrotic node of Rouvière is seen in the right lateral RPS.

Case D features left jugular vein occlusion with a heterogeneous enhancing septated fluid collection deep to the left sternocleidomastoid and extending into the RPS. Asymmetric level II lymph nodes also are present, with a necrotic node seen on the left. Multiple pulmonary septic emboli also are seen on the patient’s concurrent chest CT scan.

In Case E, a single chest radiograph demonstrates widening of the posterior mediastinum. CT of the neck and chest demonstrates a very large heterogeneous fatty mass that extends from the hypopharynx to the carina and causes significant displacement of the trachea and esophagus. MRI shows a large, septated, slightly heterogeneous lipomatous mass extending from the angle of the mandible down through the RPS and into the lower neck behind the right thyroid gland. From the thoracic inlet, the mass extends into the mediastinum, enveloping the trachea and compressing it anteriorly.