A case of hepatocellular carcinoma mimicking cavernous hemangioma on Tc-99m RBC liver SPECT

To what extent can diverse types of liver lesions mimic hemangiomas? A retrospective quantitative analysis of masses found to be positive in SPECT/CT with labeled blood cells - a preliminary report

Background

Although specificity of SPECT/CT examination using technetium-99m radiolabeled red blood cells (Tc-99m-RBC) for detection of liver hemangiomas is very high, it is still not perfect. It is possible to overlook a malignancy. Moreover, the difference in accumulation of RBCs between a hemangioma and uninvolved liver remains unknown.

The aim of the study is to determine the quotients of accumulation of Tc-99m-RBC in hemangiomas and in normal liver parenchyma (HEM/liv), and to verify, whether the quotient could be potentially helpful in distinguishing hemangiomas from other RBC-accumulating liver masses.

Material/Methods

34 liver lesions larger than 1.5 cm classified scintigraphically (qualitatively) in our Department as either typical or suspicious of hemangioma 1.5–4 years earlier were enrolled in this retrospective study. Their SPECT/CT images were acquired 1 hour after in vivo labeling of RBCs with Tc-99m. In reconstructed images, ellipsoidal regions of interest (ROIs) with diameters of about 1.5 cm were created in the assessed lesions (HEM) and in the uninvolved liver parenchyma (liv). The HEM/liv quotients were calculated for each mass. The results were compared with radiological data.

Results

31 lesions were found to be clinically and radiologically typical for hemangiomas, their HEM/liv ratios were at least 1.6 (smaller masses) or 1.8 (larger masses). One lesion with HEM/liv ratio equal to 1.21 was classified as metastasis. Two lesions with HEM/liv 1.42 and 1.46 were classified as benign foci other than hemangioma.

Conclusions

The quantitative analysis can be preliminarily proposed as a helpful tool in the assessment of possible liver hemangiomas.

99mTc-red blood cells SPECT and planar scintigraphy in the diagnosis of hepatic hemangiomas

The aim of the study is the assessment of the value of SPECT (single photon emission computerized tomography) using 99mTc-labeled red blood cells in the detection of liver hemangioma, in comparison to planar imaging. With planar red blood cell scintigraphy, sensitivity of the method was 76%, specificity 98%, positive predictive value 98% and negative predictive value 79%. With SPECT, sensitivity of the method was 95%, specificity 98%, positive predictive value 98% and negative predictive value 94%. The smallest lesion detected by planar red blood cell scintigraphy was 1.2 cm, and with SPECT red blood cell scintigraphy 0.8 cm. The use of 99mTc-labeled red blood cells SPECT improved the sensitivity much more in smaller lesions (0.8 to 2 cm), than in bigger ones (2-5 cm). SPECT with radiolabeled red blood cells significantlyy improves the results of scintigraphic findings, especially in the small lesions.

Pelioid-type hepatocellular carcinoma with numerous eosinophilic infiltrations in a patient with primary biliary cirrhosis

A 65-year-old woman with liver injury was referred to our hospital in 1992. She was diagnosed with primary biliary cirrhosis (PBC) of Scheuer's histological classification stage IV. She was treated with 600 mg/day of ursodeoxycholic acid. A 1-cm mass in S7 was detected in August 1995. The serum alpha-fetoprotein (AFP) level increased to 1288 ng/mL in January 1996. Angiography showed a cotton wool-like appearance in the delayed phase. Because the size of the tumor appeared to be increasing and the serum AFP levels increased with high levels of L3 fraction, a pelioid-type hepatocellular carcinoma (HCC) was strongly suspected. Hepatic artery infusion with SMANCS and partial resection of S7 and S8 of the liver were performed in March 1996. The pathological diagnosis for theresected liver tumor was pelioid-type HCC. The serum AFP level decreased to 50 ng/mL after the operation, but relapsed HCC was detected in S6 and S7. Angiography in September 1996 revealed multiple hypervascular lesions, and hepatic artery infusion with SMANCS was again performed; however, we were unable to suppress the progression of the relapsed HCC. The patient died due to an intra-abdominal rupture of relapsed HCC and subsequent liver failure in December 1996. We report a rare case of pelioid-type HCC with numerous eosinophilic infiltrations arising from PBC.

99mTc-labelled red blood cell single-photon emission computed tomography for the diagnosis and follow-up of juvenile nasopharyngeal angiofibroma

AIM

To confirm the usefulness of blood pool scintigraphy with Tc-labelled red blood cells ((99m)Tc-RBCs) in the diagnosis and follow-up of juvenile nasopharyngeal angiofibroma.

METHODS

A prospective study design was used. (99m)Tc-RBCs were prepared by a modified in-vivo method. After the rapid intravenous injection of 370-740 MBq of (99m)Tc-RBCs, dynamic imaging of 1-min duration was performed. After dynamic imaging, static acquisitions at 5 min (second phase: blood pool phase) and 2 h (third phase: static image) were obtained. In addition, single-photon emission computed tomography (SPECT) imaging was performed at 2 h. SPECT images were obtained using a rotating gamma camera (GE-Starcam 4000 XR/T).

RESULTS

All patients showed no activity in the first phase and mild activity in the second phase (blood pool phase). All patients with juvenile nasopharyngeal angiofibroma showed a prominent increased activity in the third phase and in SPECT images.

CONCLUSIONS

This study shows that blood pool scintigraphy with (99m)Tc-RBC SPECT is very accurate, easy to perform and a suitable alternative to pre-operative and post-operative imaging techniques, including computed tomography scan, magnetic resonance imaging (MRI) and MRI angiography, for the detection of juvenile nasopharyngeal angiofibroma.