A case of hepatic splenosis in the setting of iron overload; multimodal and literature review

Abstract

Hepatic splenosis, a rare entity, is the ectopic implantation of splenic tissue into the hepatic parenchyma, most often incidentally seen in patients with a history of splenic trauma and splenectomy. We present a unique case of hepatic splenosis in a patient with hemosiderosis and splenectomy following the incidental finding of hepatic masses on pretransplant imaging. Final diagnosis was made based on cross-sectional imaging characteristics matching that of the left upper quadrant splenules alone. We discuss common characteristics of hepatic splenosis on multiple modalities, the effect of iron deposition on the imaging characteristics of hepatic and splenic tissue and how that impacts the differential and diagnosis. This case highlights the unique imaging characteristics hepatic splenosis can have particularly in the setting of hemosiderosis. Hepatic splenosis imaging diagnosis has a significant advantage over tissue diagnosis in terms of decreased risk, time and cost.

Keywords: CT, Computed Tomography; ESRD, End Stage Renal Disease; HS, Hepatic Splenosis; Hemosiderosis; Hepatic masses; Hepatic splenosis; Iron deposition; Iron overload; MRI, Magnetic Resonance Imaging; Siderosis; Splenectomy; Splenosis; Tc-99m-DRBC, Tc-99m labelled heat-denatured red blood cells; US, Ultrasound.

Fig. 1

Findings: Axial CT images demonstrate a hepatic mass with surrounding fat border at the left hepatic lobe (blue arrow) as well as left upper quadrant splenule (orange arrow) with matching CT enhancement in each phase. Technique: Axial contrast enhanced CT abdomen and pelvis in noncontrast (A), arterial (B), venous (C), and delayed (D) phases. 120 KV, 105 mAs, 3 mm slice thickness, 150 ml Isovue IV contrast. (Color version of the figure is available online).

Fig. 2

Findings: Coronal CT demonstrates two left hepatic lobe hepatic splenules with avid contrast enhancement in arterial phase imaging (B) with decreased enhancement on venous (A). The most superior splenule (blue arrows) demonstrates surrounding fat capsule, while the inferior demonstrates hepatic margin irregularity (white arrows). Technique: Coronal contrast enhanced CT abdomen and pelvis with multiple reformats. 120 KV, 264 mAs, 3 mm slice thickness, 150 ml Isovue IV contrast. (A) Venous phase imaging (B) Arterial phase imaging. (Color version of the figure is available online).

Fig. 3

Findings: Axial (A) and Coronal (B) T2 weighted images demonstrate a markedly hypointense background hepatic parenchyma. Within the left hepatic lobe there is a hepatic splenule (blue arrow) with surrounding fatty capsule (curved blue arrow) which demonstrates marked T2 hypointensity (blue arrows) which matches the T2 signal intensity of the left upper quadrant splenule (orange arrow). Technique: (A) Axial T2-weighted, noncontrast MRI (3T, TR = 1600, TE = 86, 4 mm slice thickness) (B) Coronal T2-weighted, noncontrast MRI (3T, TR = 1500, TE = 92, 4 mm slice thickness). (Color version of the figure is available online).

Fig. 4

Findings: Axial T1 imaging with fat saturation demonstrates hyperintense T1 background hepatic parenchyma intensity as compared to the paraspinous muscles. Within the left hepatic lobe there are at least two splenules demonstrating T1 hypointensity. The left upper quadrant splenule (orange arrow) demonstrates marked T1 hypointensity, matching the signal intensity of the hepatic splenules. Technique: Axial T1 weighted image, noncontrast MRI (3T, TE =1.89, TR = 3.9, 4 mm slice thickness). (Color version of the figure is available online).

Fig. 5

Findings: Dual phase imaging with In (A) and Out (B) of phase imaging demonstrates hepatic parenchyma signal dropout on In phase imaging, compatible with hemosiderosis. Technique: (A)  In phase image, noncontrast MRI (3T, TR = 200, TE = 2.46, 4 mm slice thickness). (B) Out of phase image, noncontrast MRI (3T, TR = 200, TE = 1.23, 4 mm slice thickness). (Color version of the figure is available online).

Fig. 6

Findings: High b-value weighted imaging demonstrates no change in diffusion restriction within the hepatic splenule. Technique: B weighted, noncontrast MRI (3T, TR = 7800, TE = 58, 4 mm slice thickness). (Color version of the figure is available online).

Fig. 7

Findings: Figure A: Real time sonographic images demonstrate isoechoic mass at the left hepatic lobe measured at 3.5 × 3.4 × 2.9 cm (straight blue arrows). Figure B: Sonographic image demonstrates surrounding hyperechoic rim (curved blue arrow) and posterior enhancement. Technique: Real time ultrasound of the liver using a curvilinear probe. (Color version of the figure is available online).