Splenosis mimicking peritoneal metastasis
[Sep 2017]

We present a case of a 69-year-old male patient, who was admitted with pneumonia. The initial abdominal ultrasound performed in the admission room demonstrated presence of an oval structure in the left epigastrium, the nature and origin of which was difficult to define. Apart from a postsurgical scar in the left upper abdominal quadrant, physical examination of the patient demonstrated no abnormal findings. The patient had no family history or related diseases. He had a history of splenectomy following abdominal trauma 40 years ago. Laboratory testing including tumor markers demonstrated no abnormalities apart from raised C-reactive protein (CRP) as a sign of inflammation secondary to the pneumonia.
Computed tomography of the abdomen demonstrated no spleen and numerous small nodules of up to 28 mm between intestinal loops and between the liver and diaphragm suggesting a disseminated neoplastic process, thought to be most probably, peritoneal carcinomatosis. The arrow on the scan illustrates the lesion that was biopsied which excluded neoplasia and demonstrated splenic tissue.

Computed tomography of the chest revealed pneumonic infiltration but was otherwise normal. The endoscopic examination of the upper and lower gastrointestinal tract was normal. Contrast enhanced ultrasound (CEUS) showed arterial and late phase enhancement lasting more than 5 minutes in all examined nodules. After Biopsy the ultrasound examination was performed showing multiple almost echofree but also echogenic round and oval shaped focal peritoneal masses with a size of up to 46 mm [Figure 2-4].

Splenosis is a rare disease caused by autotransplantation of splenic cells [1]. The first description of splenosis was described by H. Albrecht in 1886 [2]. The term ‘splenosis’ was used for the first time by Buchbinder and Lipkoff in 1939 [3]. The majority of cases of splenosis are reported after traumatic splenectomies and only few after elective splenectomies performed in the course of hematological diseases [1]. Incidentally discovered splenosis may occur in any location of the abdominal cavity. In rare circumstances and depending on the location, splenosis may trigger various symptoms. The most frequent symptoms of abdominal splenosis include abdominal pain, gastrointestinal bleeding [4] and intestinal obstruction [5]. Thoracic splenosis has been reported to cause hemoptysis. Other rare locations of splenosis reported include subcutaneous tissue [6] and the occipital lobe [7]. Imaging findings including CT and magnetic resonance imaging (MRI) may be misleading not taking into account the various locations of splenotic nodules.

Contrast enhanced ultrasound (CEUS) was performed late in the diagnostic process but showed indicative signs of splenic tissue. The CEUS features that are suggestive of splenic tissue are heterogenous arterial enhancement (zebra phenomenon) and long lasting enhancement without wash out lasting for more than four minutes. The findings are in accordance with the guidelines of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) [8] excluding metastates with typical early washout [9].

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