The noninvasive diagnosis of a retrocardiac spleen as a component of a diaphragmatic hernia has not been previously reported, to our knowledge. We described herein the cardiac ultrasound, computed tomographic (CT), and radionuclide imaging features of such a case; the diagnosis was confirmed at surgery.
Case Report
A 54-year-old man had a history of chronic alcohol abuse and recurrent pancreatitis. His admission was for severe upper abdominal pain, which was diagnosed as an exacerbation of pancreatitis. Serial serum amylase levels were elevated, though fluctuating. The patient complained of episodes of chest pain; the electrocardiogram showed nonspecific anterolateral ST-T changes. The findings from a dipyridamole thallium cardiac scan were normal. Radiography of the chest showed a normal cardiac silhouette, but a large posterior mediastinal mass detected. Upper gastrointestinal barium studies showed a large paraesophageal hernia. Two-dimensional echocardiography revealed a large ill-defined solid extrinsic mass encroaching on the posterior aspect of the left atrium. A CT of the thorax with oral and intravenous contrast material demonstrated a large posterior mediastinal mass (Diaphragmatic hernia) containing the barium-filled stomach (Fig 1), as well as a well-defined homogeneous solid mass adjacent to the stomach. The presence of a notch on the anterior edge of this solid mass suggested the possibility that it was the spleen; other diagnostic possibilities included a gastric or perigastric neoplastic mass or lymphadenopathy.
Comparison of the CT of the abdomen with a previous similar examination done two years earlier showed a splenic opacity in the normal splenic location in the earlier 1988 study, that was no longer present on the recent 1990 CT.
A [Tc.sup.99m] sulfur colloid liver-spleen scan showed splenic activity above the diaphragm (Fig 2). Surgery for repair of the paraesophageal diaphragmatic hernia confirmed the presence of an intrathoracic spleen within the hernia.
Discussion
The normal spleen is a partially mobile organ, lying free within the peritoneal cavity except for its attachment to the stomach by the gastrosplenic ligament and to the kidney by the lienorenal ligament. If the stomach moves up into the thorax, in a large paraesophageal hernia, it is conceivable that the spleen, attached to the greater curvature of the stomach by the gastosplenic ligament, might accompany the stomach into the intrathoracic hernial sac.
Encroachment of a sliding hiatal hernia or a paraesophageal diaphragmatic hernia onto the left atrium has recently come to the attention of echocardiographers.[1-3] Typically, the hernia presents as a large amorphous convex mass impinging upon and partly deforming the posterior aspect of the left atrium.
A CT. particularly when accompanied by ingestion of barium, is very helpful in identifying paraesophageal or esophageal hiatal hernias.[4,5] A large rounded mass is seen anterior to the spine and descending aorta but posterior to the heart and quite separate from it. The mediastinal spread of thoracic malignant neoplasms, notably of the lung or esophagus, can also present as a posterior mediastinal mass[3] but in our experience (six cases) has always been accompanied by a pericardial or pleural effusion (or both), easily detectable on the echocardiogram and CT.
On rare occasions, splenic tissue has been identified within the thorax as a sequela of trauma which simultaneously caused rupture of the diaphragm and the spleen.[6,7] In these cases, as well as in rare instances of splenic herniation through a congenital diaphragmatic defect,[8] the supradiaphragmatic mass has been located in the posterolateral thorax, rather than in the mediastinum; however, in our patient, there was no history of trauma, and the spleen was found within a paraesophageal hernia. The differential diagnosis of a posterior mediastinal solid mass, in light of the present case, should include a retrocardiac spleen. The detection of a notch on the border of the mass and the absence of the spleen in its normal abdominal location on CT of the abdomen would suggest the splenic origin of such a retrocardiac mass.
References
[1.] Nishimura RA, Tajik AJ, Schattenberg TT, Seward JB. Diaphragmatic hernia mimicking an atrial mass: a two-dimensional echocardiographic pitfall. J Am Coll Cardiol 1985; 5:992-95 [2.] Baerman JM, Hogan L, Swiryn S. Diaphragmatic hernia producing symptoms and signs of a left atrial mass. Am Heart J 1988; 116; 198-200 [3.] D'Cruz IA, Hoffman PK, Ewald FW. Echocardiography of posterior mediastinal masses encroaching on the left atrium. Echocardiography 1989; 6:485-95 [4.] Lindell MM, Bernadino ME. Diagnosis of hiatus hernia by computed tomography. J Comput Tomogr 1981; 5:16-19 [5.] Vas W, Malpani AR, Singer J, Sundaram M, Chenowith J. Computed tomograph evaluation of paraesophageal hernia. Gastrointest Radiol 1989; 14:291-94 [6.] Moncha R, Williams V, Fareed J, Messmore H. Thoracic splenosis. AJR 1985; 144:705-06 [7.] Scales FE, Lee ME. Nonoperative diagnosis of intrathoracic splenosis. AJR 1983; 141:1273-74 [8.] Roy DV, Pattison CW, Townsend ER. Spelic herniation. Scand J Thorac Cardiovasc Surg 1988; 22:83-5
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