Calcification in Thoracic Splenosis

Abstract

Splenosis is a rare condition described as the implantation of ectopic splenic tissue, usually after a splenic rupture. Thoracic splenosis refers to acquired ectopic splenic tissue found within the thoracic cavity, often caused by thoracoabdominal trauma or surgery. Most cases are asymptomatic and many years may elapse before they are incidentally discovered on chest radiography or thoracic computed tomography. Splenosis is often misinterpreted as a malignancy on initial imaging. We wish to highlight a rare case of thoracic splenosis presenting with calcified and non-calcified nodules. Only two other cases of calcification have been reported in intrathoracic splenosis, neither of which provided CT images of this finding.

Figure 1

Chest X-ray. (a) Anteroposterior view showing a 1.7x1.4 cm nodular density at the level of aortic arch (red arrow). No other definitive nodules were seen. (b) Posteroanterior radiograph six months later, revealing the previously noted nodular density (red arrow) that remains unchanged and several new nodular opacities (white arrows) in the left upper and left lower lung fields.

Figure 2

Computed tomography of the chest without contrast. (a) Axial view, mediastinal window at the level of the aortic arch reveals three pleural based nodules one of which is densely calcified, round, and smoothly marginated. (b) Axial view, mediastinal window of the lower thorax shows two pleural based smoothly marginated nodules of soft tissue density, one of which is partially calcified and lobulated (white arrow). (c) Sagittal view, lung window of left hemithorax showing four non-calcified pleural based nodules, one of which is lies along the left major fissure. Note the absence of the spleen.

Figure 3

Pathology findings of the left pleural nodule showing (a) splenic tissue with a thick collagen band representing the splenic capsule (H&E stain, 100x). (b) Splenic tissue with congested blood-filled sinuses representing red pulp and lymphoid aggregates surrounding vascular structures representing white pulp (H&E stain, 400x).