Case Report # 1

1. Radiological Category: Gastrointestinal Principal Modality (1): Principal Modality (2): MRI None Case Report # 1 Submitted by: Austen W. Worsham, MSIV Faculty reviewer: Dr. Oldham Date accepted: 8/29/2007

2. Case History A 63 year old AA man presented to an outside hospital 4 months ago with complaints of painful abdominal distention, weight loss (150 lbs) and early satiety for about six months. Physical examination revealed an enlarged nodular liver. He had a pathological diagnosis. He now presents to the Texas Liver Center for evaluation. Pertinent Information No history of prior liver disease No history of alcohol use No history of steroid use No history of glycogen storage disease No known toxic exposures Hepatitis panel: negative AFP wnl

3. Radiological Presentations Dynamic contrast enhanced, arterial phase MR

4. Radiological Presentations Out of phase T1 Dynamic delayed phase

5. Radiological Presentations In Phase

6. Radiological Presentations Signal drop out out of phase

7. Radiological Presentations T2 Axial T2WI T2 axial

8. Radiological Presentations T2WI

9. Radiological Presentations T2WI

10. Radiological Presentations T2WI

11. Radiological Presentations T2WI

12. Test Your Diagnosis Which one of the following is your choice for the appropriate diagnosis? After your selection, go to next page. • Hepatocellular Carcinoma • Multiple Hemangiomas • Hepatic Adenomatosis • Focal Nodular Hyperplasia • Fibrolamellar Carcinoma • Cholangiocarcinoma • Hepatic Metastases • Multiple Cysts • Nodular Regenerative Hyperplasia

13. Almost the entire liver is replaced by numerous nodules of varying sizes involving all segments of both lobes. The liver is enlarged and macronodular. Some nodules show signal drop-out on the out-of-phase images. Several nodules are hyperintense on both in and out-of-phase, suggestive of hemorrhage within the nodule. There is arterial phase postcontrast enhancement and washing out on the delayed images. Moderate bile duct dilation due to large central masses. Findings and Differentials Findings: Differentials: • Multifocal Hepatocellular Carcinoma • Hepatic Adenomatosis • Cholangiocarcinoma • Nodular Regenerative Hyperplasia • Multiple Hemangiomas • Focal Nodular Hyperplasia • Fibrolamellar Carcinoma • Multiple Metastases

14. This patient’s work up was already completed at an outside hospital when he was evaluated at Hermann. For this reason he only received an MRI to determine the progression of his disease and to see if it would be possible to explant or chemoembolize his liver. Had there not already been a pathological diagnosis, this could have been a difficult radiological diagnosis to make, owing to the fact that on MRI, many of the disease entities on the differential share both gross features and signal intensity patterns. There are, however, some features that may help in narrowing the differential. Discussion

15. Hepatic Adenoma: A rare benign entity with an overall incidence of about 1 in 1 million persons. There is an increased incidence with oral contraceptives, anabolic steroids, glycogen storage diseases (esp. Von Gierke’s and Cori’s), and tyrosinemia. About 90% of adenomas occur in young women and are associated with oral contraceptive use; many of these may regress after discontinuation of OCPs. Histologically, adenomas are composed of sheets of normal appearing hepatocytes that lack the normal acinar structure. These hepatocyes are rich in fat or glycogen but bile ducts and portal tracts are absent. They may have a pseudocapsule which is known to spontaneously rupture in 25-50% of cases. Malignant degeneration is very rare. The classic presentation is spontaneous rupture with hemorrhage leading to abdominal pain, hypotension and shock. Another common presentation is RUQ pain and fullness. Hepatic Adenomatosis: Distinguished by the presence of mutiple adenomas. These adenomas range from ~ 1cm to 15cm in size and are more prone to hemorrhage and malignant degeneration than solitary adenomas. Adenomatosis does not share the association with steroid use; and it occurs equally in men and women. Discussion

16. MRI Imaging of Adenomas: T1WI: The signal intensity varies form hypo to hyperintense. This is due to the variable fat content of adenomas. T2WI: They are most often hyperintense. This finding is not specific to adenomas. On both modalities, they may also have a heterogeneous appearance due to areas of hemorrhage, necrosis or calcification. Dynamic gadolinum enhanced imaging demonstrates that most adenomas are intensely enhancing during the early arterial phase and are isointense to liver parenchyma on portal venous phase and hypointense on delayed imaging. Signal drop out on out-of-phase or fat suppressed images is a common finding. “Nodule in nodule” appearance. Discussion

17. Discussion Hussain, S. M. et al. Radiographics 2002;22:1023-1036 Grazioli, L. et al. Radiographics 2001;21:877-892

18. Hepatocellular Carcinoma: HCC is the most common primary hepatic malignancy. It is most commonly associated with Hepatitis B and C, hemochromatosis and cirrhosis. The lesions can be solitary(50%), multifocal (40%) or diffusely infiltrating (<10%). Histologically, HCC consists of abnormal hepatocytes arranged in a trabecular pattern. The solitary form consists of a single large infiltrating tumor, and in most cases is not associated with cirrhosis. The multifocal (nodular) form is characterized by the presence of one or more encapsulated or non-encapsulated nodules and is seen mostly in cirrhotics. The diffuse form is characterized by infiltration into the parenchyma. The solitary and multifocal forms of HCC are hypervascular, with blood supply derived form the hepatic artery. HCC often exhibits intratumoral necrosis, hemorrhage, fatty change (<10%) and portal and hepatic vein invasion with associated thrombosis. Discussion

19. MRI findings: T1WI: HCC has variable intesity. T2WI: HCC is generally isointense to hyperintense. It can be hypovascular or hypervascular (most). HCC does not usually demonstrate signal drop out on in and out of phase imaging due to the low incidence of fatty change. On dynamic gadolinium enhanced imaging, HCC will enhance in the arterial phase and will be isointense in the portal phase and hypointense in the delayed phase. The appearance is variable and is determined by the level of differentiation. On the initial MRI this patient had at the outside hospital the radiologist concluded that this was HCC, this was shown to be incorrect at surgical wedge resection and pathological examination. At the time of this imaging the liver was not so grossly enlarged. Discussion

20. Cholangiocarcinoma: Malignancy of the biliary tract. There are 5,000 new cases every year in the U.S. There is a strong association with primary sclerosing cholangitis, also some association with HCV and alcoholism. It may be intrahepatic or extrahepatic (involving the CBD). It usually presents as a mass between 5-20cm, and has a varied morphology and histology. For this reason it is very difficult to make this diagnosis with abdominal CT or MRI, though cholangiography, ERCP, MRCP and PET imaging are helpful. Nodular regenerative hyperplasia: NRH is a condition in which multiple foci of proliferating hepatocytes with surrounding fibrous septae form nodules throughout the liver. It is frequently associated with a systemic disease such as Hepatitis B or C, and occurs more commonly among the elderly. MRI findings: T2WI and gadolinium enhanced: hypointense with hyperintense septae. Discussion

21. Hemangioma: The most common benign liver tumor. They are composed of vascular channels, and may vary in size from mms to 10cm, and are most often multiple. Complications are rare unless the hemangioma is large, and include rupture and hemorrhage, obstructive jaundice, CHF secondary to AV shunting. They do not usually require treatment. MRI findings: T1WI: Homogeneous low intensity lesions T2WI: Hyperintense They show early enhancement peripherally and on delayed images show peripheral washout. Appearance should always match the blood pool. Discussion

22. Focal Nodular Hyperplasia: The second most common benign liver tumor. It is thought to represent a hyperplastic response to increased blood flow through an intrahepatic AVM. Histologically, it has all of the normal liver components but in an abnormal arrangement. It is not associated with estrogen. Usually asymptomatic - no treatment necessary. MRI findings: T1WI: Hypointense T2WI: Isointense to hyperintense with a central area of even higher signal intensity (central scar). Postcontrast enhancement and absence of a capsule. Fibrolamellar Carcinoma: An uncommon hepatic tumor, occurs in adolescents and young adults. It is not associated with cirrhosis, hepatitis, alcohol or estrogen use. The typical appearance is of a heterogeneous mass with a central scar. Mesenteric adenopathy is often seen. MRI findings: Difficult to distinguish from FNH, hepatoma, hemangioma and cholangiocarcinoma because they can all have central scaring. They may be differentiated by noting that the central scar in fibrolamellar carcinoma is hypointense on T2WI. Discussion

23. Hepatic metastases: The liver is the most common site of metastases. The cancers that commonly go to the liver are lung, breast, colon, and stomach. Mets to the liver are usually multiple, and they can be divided into two categories: hypovascular and hypervascular. Hypovascular: These are the most common and are from colon, lung, breast, and head and neck tumors. Hypervascular: These are from the renal cell, insulinomas, carcinoid, sarcomas, and melanomas. MRI Findings: T1WI: Usually hypointense T2WI: Hyperintense, peritumoral edema makes the tumor look larger than it is and is very suggestive of malignancy. Peripheral enhancement on arterial phase and washout on delayed images Discussion

24. While the differential can be narrowed down on imaging, it can be difficult to make a definitive diagnosis of a liver mass since they share many of the same features and intensities on MRI. In these situations imaging should serve as a complement to clinical history, laboratory and pathological assessment. At present, this patient is not a transplant candidate due to his severe malnutrition (150 pound weight loss) and the surgical complexities of removing such a grossly enlarged liver. Discussion

25. Hepatic Adenomatosis Diagnosis

26. 1. Baron, Richard. Liver Masses Part II: Common Liver Tumors. The Radiology Assistant. http://www.radiologyassistant.nl/en/2. Bittle, Michelle M., Chew, Felix S. Radiological Reasoning: Incidentally Discovered Liver Mass. Am. J. Roentgenol. 2006; 186: S434-441. 3. Brancatelli, Guiseppe, Federle, Michael P. CT and MRI Imaging Evaluation of Hepatic Adenoma. Journal of Computer Assisted Tomography. 2006; 30: 745-750.4. Grazioli, Luigi, Federle, Michael, et al. Hepatic Adenomas: Imaging and Pathologic Findings. RadioGraphics. 2001. 21:877-892.5. Hussain, Shahid M., et al. Benign versus Malignant Hepatic Nodules: MR Imaging Findings with Pathologic Correlation. RadioGraphics 2002; 22: 1023-1036. 6. Ito, Katsuyoshi, et al. Liver Neoplasms: Diagnostic Pitfalls in Cross-sectional Imaging. RadioGraphics. 1996. 16: 273-293.7. Up-to-Date References