**5. Signs and symptoms**

Most commonly, HA goes unnoticed due to its lack of signs and symptoms, but when it does become symptomatic, it is either due to its increase in volume, tumor necrosis, or complications such as life-threatening intra-abdominal bleeding due to spontaneous rupture of the highly vascularized tumor. Sudden, severe pain with hypotension in a patient with HA indicates rupture into the peritoneum, an event associated with a mortality of up to 20 percent if not identified and/or treated accordingly [9, 31, 32]. The risk of bleeding is difficult to estimate overall, but it is quite high in patients with symptomatic HAs (25–64%). Tumor size that exceeds 35 mm has been associated with an increased risk of bleeding [33]. The risk of bleeding depends on the localization of the tumor. Exophytic lesions (protruding from liver) had the highest risk of bleeding (67%), followed by subcapsular ones (19%) and at last intrahepatic HA (11%). Lesions in segments II and III had more bleeds than those in the right liver (34% versus 19%). The visualization on imaging of peripheral or central arteries represents a risk of bleeding comparative with no visible vascularization in the lesion [33]. Also a long history of contraceptive use and recent hormonal use are risk factors for bleeding from HA. Young age seems to be associated with an increased incidence of HA rupture, independent of hormonal treatment duration, suggesting a need for careful surveillance or prophylactic treatment in this population [34]. Bleeding is graded as intratumoral (grade I), intrahepatic (grade II), or extrahepatic (grade III) and represents a potentially life-threatening complication in patients with HAs.

Hepatic adenomas are diagnosed when they cause epigastric or upper quadrant pain or during an imaging study done for unrelated ailments, and less commonly when an abdominal mass is palpated on clinical examination. When HA is sufficiently large and compresses bile ducts, jaundice may become another sign.

#### **6. Diagnosis and differential diagnosis**

There are no specific serologic markers or laboratory findings for HA, but certain findings can lead the diagnosis away from an adenoma and toward a liver cell carcinoma in case of an increased serum alpha-fetoprotein, or toward a metastasis in the case of increased serum tumor markers for digestive tract tumors [35].

The definite diagnosis in this pathology is naturally a histological one; however, obtaining it preoperatively means making a biopsy from a fragile and highly vascular tissue, with significant risk of bleeding. Having to deal with a benign lesion, and given the fact that the amount of tissue obtained is rarely enough or suitable for a diagnosis, this risk is not justified. Thus, the diagnosis of this tumor is based on analyzing a combination of epidemiologic and clinical data and imaging studies, but often the confirmation of the diagnosis is done by the pathologist, after the hepatic resection.

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**Figure 13.**

*Challenging Issues in Hepatic Adenoma DOI: http://dx.doi.org/10.5772/intechopen.87993*

imaging characteristics.

**6.1 Imaging in liver adenomas**

imaging (MRI) (**Figure 13**).

to US without contrast.

*6.1.2 Computer tomography*

usually a sign of necrosis, hemorrhage, or fibrosis [5].

*6.1.1 Ultrasound*

Usually a HA is suspected in a young adult with a singular and asymptomatic hepatic lesion, but a thorough differential diagnosis should be made and often this proves to be difficult. The differential diagnosis between adenomas and focal nodular hyperplasia is usually challenging, but can be done, most of the times, based on

Imaging in adenomas includes mostly ultrasound, contrast-enhanced ultrasound (CEUS), multislice computer tomography (MSCT), and magnetic resonance

The most accessible, cost-friendly, and probably responsible for most discoveries of asymptomatic HA is the ultrasound, even though it cannot distinguish it from other liver tumors. On gray scale ultrasound, HA is seen as a well-defined solid, echogenic mass, but sometimes as complex hyper/hypoechoic, heterogeneous mass with anechoic areas due to fat, hemorrhage, necrosis, and calcifications; a capsule may also be seen [36]. Color Doppler US can aid in the distinction from FNH in the absence of a central arterial signal, FNH having characteristic intratumoral and peritumoral vessels [37, 38]. Contrast-enhanced ultrasound with sulfur hexafluoride microbubbles (SonoVue or Lumason) greatly improves diagnosis as compared

One of the most accurate imaging tools in diagnosing a HA is contrast enhanced computed tomography (CECT), on which it appears as a well demarcated tumor, with characteristic peripheral enhancement during the early phase with subsequent centripetal flow during the portal venous phase. A heterogeneous consistency is

Multiphasic computed tomography (CT) has a detection rate of 100% for adenomas, which is however different per type of examination: nonenhanced 86%, hepatic arterial-dominant phase (HAP) 100%, portal venous-dominant phase (PVP) 82%, and delayed 88%. Tumor margins are well defined by a low-attenuation pseudocapsule in 86% of adenomas and the surface appears smooth, without lobulated contour, in 95%. Tumor fat and calcifications are uncommon (7%, respectively 5%). Other than areas of fat, hemorrhage, or necrosis, the adenomas show homogenous enhancement, especially on PVP and delayed-phase scans [39].

*HA located in segment VII as shown by imaging on NECT (A), CECT—arterial phase (B), portal venous phase (C), parenchymal phase (D), MRI T1w (E), and T2w (F). Atoll sign characterized by a hyper intense band in the periphery and isodensity in the center of the lesion with respect of the surrounding liver is relevant on CT in portal venous phase (C). A hyperintense rim in T2 wi is described in inflammatory adenoma (arrow in F).*

#### *Challenging Issues in Hepatic Adenoma DOI: http://dx.doi.org/10.5772/intechopen.87993*

Usually a HA is suspected in a young adult with a singular and asymptomatic hepatic lesion, but a thorough differential diagnosis should be made and often this proves to be difficult. The differential diagnosis between adenomas and focal nodular hyperplasia is usually challenging, but can be done, most of the times, based on imaging characteristics.

## **6.1 Imaging in liver adenomas**

Imaging in adenomas includes mostly ultrasound, contrast-enhanced ultrasound (CEUS), multislice computer tomography (MSCT), and magnetic resonance imaging (MRI) (**Figure 13**).
