Radiological Category Gastrointestinal Principal Modality 1 MRI Principal

  • Slides: 15
Download presentation
Radiological Category: Gastrointestinal Principal Modality (1): MRI Principal Modality (2): CT Case Report #0338

Radiological Category: Gastrointestinal Principal Modality (1): MRI Principal Modality (2): CT Case Report #0338 Submitted by: Gustav A. Blomquist, M. D. Faculty reviewer: Larry Kramer, M. D. Date accepted: 31 October 2006

Case History 69 -year-old male with history of renal cell carcinoma, stage p. T

Case History 69 -year-old male with history of renal cell carcinoma, stage p. T 2, status post laparoscopic right radical nephrectomy.

Noncontrast CT Images

Noncontrast CT Images

Contrast Enhanced CT Images

Contrast Enhanced CT Images

Delayed Contrast CT Images

Delayed Contrast CT Images

MRI Reminders Lesions with short T 1 are (bright in T 1 weighted sequences):

MRI Reminders Lesions with short T 1 are (bright in T 1 weighted sequences): fat (lipoma, dermoid) sub-acute hemorrhage (met. Hb) paramagnetic agent (Gadolinium, pituitary) protein-containing fluid (colloid cyst) metastatic melanoma (melanotic). Lesions with long T 2 are (bright in T 2 weighted sequences): Fluid Very acute hemorrhage Slow flowing blood.

MR Imaging

MR Imaging

Radiological Presentations

Radiological Presentations

Test Your Diagnosis Which one of the following is your choice for the appropriate

Test Your Diagnosis Which one of the following is your choice for the appropriate diagnosis? After your selection, go to next page. • Hypovascular Metastasis • Cholangiocarcinoma • Sclerosing Hemangioma • Hepatocellular Carcinoma • Focal Nodular Hyperplasia

Findings and Differentials Findings: CT: Dynamic contrast-enhanced axial computed tomography shows two hypodense masses

Findings and Differentials Findings: CT: Dynamic contrast-enhanced axial computed tomography shows two hypodense masses in the liver, one in the right lobe, measuring 5. 5 x 5 cm, and one in the left, measuring 4. 5 x 5 cm. On precontrast images, there is marked central hypodensity with a peripheral area that is slightly more dense, but still less dense than surrounding liver. There is slight early peripheral enhancement of both lesions followed by slow lobular filling in peripherally on delayed imaging. The central hypodensity never fills in for either mass. MRI: Elliptical, lobulated, well-marginated masses, one in the left lobe and one in the right lobe of the liver. The right liver lobe lesion is causing a contour change to the liver capsule. On T 2 -weighted magnetic resonance imaging, the right lobe mass is centrally hyperintense to liver and hypointense in relation to cerebrospinal fluid. Peripherally, the mass is isointense to liver. The left lobe liver mass is isointense to hypointense on T 2. Both lesions are marginally hypointense to liver on T 1. There is no drop out of signal for either mass on the out of phase compared to the in phase imaging to suggest microscopic lipid. On dynamic imaging the lesions both peripheral enhance followed by slow lobular filling in peripherally on delayed imaging. The central part of the lesions never fill. Differentials: • Sclerosing Hemangioma • Hypovascular malignancy • Hepatocellular carcinoma

Intraoperative Biopsy In this case, an intraoperative wedge biopsy of the right lateral lesion

Intraoperative Biopsy In this case, an intraoperative wedge biopsy of the right lateral lesion consisted of a fibrotic nodule with small compressed benign blood vessels throughout it. No malignancy or metastasis from the kidney was present. The adjacent liver had bile duct proliferation and a rim of lymphocytes next to the nodule. The PAS stain was negative on the liver tissue for intrahepatocytic globules. The iron stain showed only mild iron deposits in some Kupffer cells. Reticulin stain showed a normal reticulin network. The tumor nodule stained throughout with the trichrome (fibrosis) stain, while the amyloid stain was negative. An immunohistochemical stain for CD 34, with appropriate controls, was positive, and confirmed the presence of intact and crushed endothelial cells in the nodule, consistent with hemangioma. The rim of lymphocytes and bile duct proliferation in the residual liver tissue were felt to represent mass effect from the adjacent sclerosed hemangioma. Histologically, there is a difference between a sclerosing hemangioma and a sclerosed hemangioma. The difference lies in the amount of fibrosis and the presence or absense of cavernous spaces. Radiographically, by MRI or CT, no such distinction has been made.

Discussion Sclerosed or Sclerosing Hemangiomas Hyalinized, fibrosed, sclerosing and/or sclerosed hemangiomas are rare subtype

Discussion Sclerosed or Sclerosing Hemangiomas Hyalinized, fibrosed, sclerosing and/or sclerosed hemangiomas are rare subtype of hemangiomas. In the spectrum of hemangiomas, (cavernous hemangioma, sclerosing hemangioma, and solitary fibrous nodule) these may represent different stages in the involution of hemangiomas. Microscopically, hemangiomas are made up of cavernous vascular channels. Why they form is not known. The channels are lined by single layers of flattened endothelium and are separated by fibrous septa. The vascular spaces may contain thrombin, calcifications, or scarring with hyalinization, a sclerosed hemangioma. Hemangiomas that contain phleboliths are rare, and malignant transformation has not been reported. Histologically, sclerosed hemangiomas have thrombosed vascular spaces and extensive hyaline fibrosis. The fibrosis results in the different signal characteristics from the usual hemangiomas on MR. MR imaging characteristics of sclerosed and sclerosing hemangiomas include: T 2 -WI hyperintense to liver and hypointense to CSF. The scar is hypointense on T 1 and T 2. On dynamic imaging T 1 -fat sat, there is little to no early enhancement followed by strong globular peripheral enhancement on delayed imaging. MRI can not be used to definitively diagnose a sclerosing hemangioma. In the differential, hypovascular metastasis/malignancy can not be excluded. In cirrhotic livers, hemangiomas are more likely to involute, decrease in size, and fibrose.

Bibliography Abdominal Imaging 2001 Sep-Oct; 26(5): 496 -9. Sclerosed hemangioma of the liver. Masuda

Bibliography Abdominal Imaging 2001 Sep-Oct; 26(5): 496 -9. Sclerosed hemangioma of the liver. Masuda K. J Magn Reson Imaging. 1994 May-Jun; 4(3): 506 -8. Sclerosed liver hemangioma mimicking malignant tumor at MR imaging: pathologic correlation. Mathieu D, Zafrani ES. Liver 2002 Feb; 22(1): 70 -8. Sclerosed hemangioma and sclerosing cavernous hemangioma of the liver: a comparative clinicopathologic and immunohistochemical study with emphasis on the role of mast cells in their histogenesis. Makhlouf HR, Ishak KG.