Masquerading Spleen: A Perplexing Case of Intrahepatic Splenosis Mimicking Hepatocellular Carcinoma

Abstract

Intrahepatic splenosis is an uncommon condition that can present a significant diagnostic challenge, often masquerading as more sinister hepatic lesions. We report a perplexing case of a 56-year-old female with a history of splenectomy who presented with liver masses initially suspected to be hepatocellular carcinoma (HCC). Despite advanced imaging techniques, including ultrasonography, computed tomography (CT), and magnetic resonance imaging (MRI), the lesions convincingly mimicked HCC. Surgical resection was performed, and histopathological examination revealed the true nature of the masses: intrahepatic splenosis. This case underscores the importance of considering this rare entity in the differential diagnosis of liver masses, particularly in patients with a history of splenic trauma or splenectomy. We present a review of the literature to provide context and discuss the diagnostic conundrum posed by intrahepatic splenosis.

Keywords: hepatectomy; hepatocellular carcinoma; intrahepatic splenosis; liver tumor; splenic trauma.

Figure 1. Ultrasonography image of the liver

(A) Ultrasonography image demonstrating a hypoechoic mass in segment 2 of the liver (yellow arrowhead). (B) Ultrasonography image showing a hypoechoic mass in segment 6 of the liver (yellow arrowhead). Both lesions appear well-demarcated with homogeneous internal echoes, measuring approximately 2 cm in diameter. The surrounding liver parenchyma shows a coarse echotexture, consistent with chronic liver disease.

Figure 2. Dynamic CT images of the liver

(A, B) Early arterial phase (A) and portal phase (B) of the upper abdomen, show a homogeneously enhancing mass in segment 2 of the liver (yellow arrowheads). The lesion demonstrates higher attenuation compared to the surrounding liver parenchyma in the early phase (A) and becomes relatively hypoattenuating in the portal phase (B). (C, D) Early arterial phase (C) and portal phase (D) of the lower abdomen, reveal a similar enhancing mass in segment 6 of the liver (yellow arrowheads). This lesion also shows hyperattenuation in the early phase (C) and relative hypoattenuation in the portal phase (D). Both lesions demonstrate enhancement patterns mimicking the washout typically seen in hepatocellular carcinoma, with hyperenhancement in the early arterial phase and relative hypoattenuation in the portal venous phase compared to the surrounding liver parenchyma.

Figure 3. Gadoxetic acid-enhanced MRI (EOB-MRI) of the liver

(A, C) Early arterial phase images showing hyperintense enhancement of the lesions in segment 2 (A, yellow arrowhead) and segment 6 (C, yellow arrowhead) of the liver. (B, D) Hepatobiliary phase (20 minutes post-contrast) demonstrating hypointensity of the lesions in segment 2 (B, yellow arrowhead) and segment 6 (D, yellow arrowhead) against the background of enhancing liver parenchyma. Both lesions demonstrate enhancement patterns often associated with hepatocellular carcinoma, showing hyperintensity in the early arterial phase and hypointensity in the hepatobiliary phase compared to the surrounding liver parenchyma.

Figure 4. Intraoperative images of liver resection

(A) Resection surface after partial hepatectomy of segment 2. The yellow arrowhead indicates the cut surface where the tumor was removed, demonstrating its superficial location. (B) Resection surface following partial hepatectomy of segment 6. The yellow arrowhead points to the area where the tumor was excised, also showing its proximity to the liver surface. Both images illustrate that the tumors were located relatively close to the liver surface, which facilitated successful partial hepatectomy. The exposed liver parenchyma and the surgical margins are clearly visible in both resection beds.

Figure 5. Gross pathological specimen of the resected liver segment

Gross pathological specimens of the resected liver segments show the lesions. The cut surfaces reveal two well-circumscribed, dark-red nodules, each measuring approximately 2 cm in diameter. The nodules' color and texture are consistent with splenic tissue, contrasting sharply with the surrounding liver parenchyma.

Figure 6. Histopathological images confirming intrahepatic splenosis

(A) Low-power view (Hematoxylin and eosin (H&E) stain) showing the interface between liver tissue (yellow arrowhead) and splenic tissue (red arrowhead). The clear demarcation between hepatic and splenic architecture is evident. (B) Higher magnification view (H&E stain) of the splenic tissue, demonstrating characteristic splenic architecture including white pulp (lymphoid follicles) and surrounding red pulp. These histopathological findings confirm the diagnosis of intrahepatic splenosis.

Figure 7. Proposed model for the development of intrahepatic splenosis

PV: portal vein; SV: splenic vein Diagram illustrating the proposed model for the development of intrahepatic splenosis in the context of chronic alcohol abuse. The model shows the progression from normal liver to alcohol-induced chronic inflammation, creating a permissive microenvironment for splenic cell engraftment. Subsequent stages depict the implantation, survival, and growth of ectopic splenic tissue within the inflamed liver parenchyma, facilitated by the altered local environment. Image credit: Created in BioRender. Noriko, I. (2024) BioRender.com/n19e308