Scimitar Syndrome: An Incidental Finding

Excerpt

An 11-y-old boy presented to the pediatric emergency with complaint of fever since 15 d. A routine chest X-ray and blood investigations were ordered. Based on the blood investigations, he was diagnosed with enteric fever and was started on intravenous ceftriaxone. The chest X-ray (Fig. 1) showed homogeneous haze in right lung field with marked mediastinal shift to the right side (single black), suggestive of volume loss in right lung. A curvilinear tubular shadow was noted in the right lung medially, coursing from the region of hilum inferiorly (double black arrow). A well-defined rounded opacity was noted in right chest infero-medially (arrow head), obscuring the medial part of right hemidiaphragmatic outline. The X-ray findings suggested the possibility of Scimitar syndrome or partial anomalous pulmonary venous return, with the curved shadow of an anomalous pulmonary venous channel coursing inferiorly through right lung to drain into systemic circulation. Volume loss in right lung is also a part of spectrum of the condition, which is associated with hypoplastic ipsilateral lung, and described as hypogenetic right lung syndrome. The findings were confirmed on CECT- Chest (Fig. 2). Serial CT MPR sections in coronal (Fig. 2a) and sagittal planes (Fig. 2c) demonstrated the right superior and inferior pulmonary veins uniting to form a common venous channel (Scimitar vein- single white arrow), which was seen to course infero-medially to drain into the terminal part of inferior vena cava (double white arrows). The well-defined rounded soft tissue opacity in right lower chest was identified to be a diaphragmatic hump – produced by focal eventration of the right hemidiaphragm (arrow head). Congenital anomalies of the diaphragm are a well-known association of this condition.

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