Mass Lesions In Liver Research Articles

Epithelioid variant of gastrointestinal stromal tumor: Diagnosis by fine-needle aspiration.

Epithelioid gastrointestinal stromal tumors (GISTs) may cause significant diagnostic confusion on fine-needle aspiration (FNA) with carcinomas, neuroendocrine tumors, and melanoma, particularly when metastatic. This study characterizes the cytologic features of nine cases of epithelioid GISTs that were obtained by computerized tomographic guidance in five, by endoscopic ultrasound in three, and from an excised liver tumor in one. Six cases presented as liver masses, one as a perisplenic mass, one as an abdominal mass, and one as a gastric mass. The aspirates revealed mainly single or small clusters of epithelioid cells with a moderate amount of granular to clear cytoplasm, small uniform nuclei with mild to marked nuclear envelope irregularities. Binucleation and intranuclear inclusions were frequent findings. Collagenous stroma was seen in most cases. In three cases, a neuroendocrine tumor was the initial diagnosis. Immunocytochemical staining for c-kit (CD117) was performed on cellblocks in six cases and was positive in five cases. On the subsequent surgical specimen, CD117 was positive in the c-kit-negative cytology case. The diagnosis of GIST should be considered in aspirates of the gastrointestinal tract, liver, mesentery, or abdominal wall mass lesions when epithelioid cells are the predominant cell type. Ancillary studies such as immunohistochemical stains are usually helpful in making a definitive diagnosis.

Assessment of vascular patterns of small liver mass lesions: value and limitation of the different Doppler ultrasound modalities

OBJECTIVES: This study aimed to investigate the value and limitation of the different Doppler ultrasound modalities (spectral analysis, color, and power Doppler imaging) in the differential diagnosis of small liver tumors to identify the optimal diagnostic approach with the presently available Doppler technology. METHODS: Presence and distribution of color and power Doppler signals, Doppler peak frequency, resistive index, and systolic acceleration time were examined in 133 liver nodules (≤4 cm). RESULTS: Color and power Doppler did not identify specific diagnostic vascular patterns. By discriminant analysis, peak frequency (cut-off 1320 Hz) differentiates small hematocellular carcinoma (≤2 cm) from macroregenerative nodules and hemangiomas (accuracy 92.6%); resistive index (cut-off 0.65) differentiates malignancies from benign lesions (accuracy 83.8%); and systolic acceleration time (cut-off 105 ms) differentiates hepatocellular carcinoma from metastases (accuracy 80.9%). CONCLUSIONS: Power Doppler imaging is able to assess vascularity in the majority of small liver nodules, but the pattern distribution of tumoral vascular signals does not provide reliable differential diagnostic criteria. Using conventional Doppler technology, power Doppler should be used to detect vascular signals and spectral analysis, and subsequently to measure quantitative parameters such as high peak frequency and resistive index (which identify malignancy) and prolonged systolic acceleration time (which identifies primary from metastatic liver tumors).

Assessment of vascular patterns of small liver mass lesions: value and limitation of the different Doppler ultrasound modalities.

This study aimed to investigate the value and limitation of the different Doppler ultrasound modalities (spectral analysis, color, and power Doppler imaging) in the differential diagnosis of small liver tumors to identify the optimal diagnostic approach with the presently available Doppler technology. Presence and distribution of color and power Doppler signals, Doppler peak frequency, resistive index, and systolic acceleration time were examined in 133 liver nodules (< or = 4 cm). Color and power Doppler did not identify specific diagnostic vascular patterns. By discriminant analysis, peak frequency (cut-off 1320 Hz) differentiates small hematocellular carcinoma (< or = 2 cm) from macroregenerative nodules and hemangiomas (accuracy 92.6%); resistive index (cut-off 0.65) differentiates malignancies from benign lesions (accuracy 83.8%); and systolic acceleration time (cut-off 105 ms) differentiates hepatocellular carcinoma from metastases (accuracy 80.9%). Power Doppler imaging is able to assess vascularity in the majority of small liver nodules, but the pattern distribution of tumoral vascular signals does not provide reliable differential diagnostic criteria. Using conventional Doppler technology, power Doppler should be used to detect vascular signals and spectral analysis, and subsequently to measure quantitative parameters such as high peak frequency and resistive index (which identify malignancy) and prolonged systolic acceleration time (which identifies primary from metastatic liver tumors).

The utility of fine-needle biopsy of liver mass lesions in patients with cirrhosis and serum alphafetoprotein less than 500

The utility of fine-needle biopsy of liver mass lesions in patients with cirrhosis and serum alphafetoprotein less than 500

Accurate preoperative evaluation of liver mass lesions without fine-needle biopsy.

Fine-needle biopsy (FNB) is associated with problems, such as tumor seeding, which are probably underestimated. The aim of this study was to validate prospectively the accuracy of our diagnostic work-up without FNB, for defining indications for surgery in a cohort of patients with focal liver lesions (FLLs). Between January 1997 and December 1998, 160 consecutive patients carrying 225 FLLs admitted to our department were evaluated prospectively. Preoperative diagnoses were established by means of clinical histories, serum tumor marker levels, ultrasonography, and spiral computed tomography (CT). Angiography, magnetic resonance imaging (MRI), and Lipiodol-CT were performed when it was considered necessary to plan the surgical strategy. All the patients underwent surgery and results of pathological examinations were obtained for all of them. The preoperative diagnoses of 221 of the 225 lesions (98.2%) were confirmed, and the indications for liver resection in 156 of the 160 patients (97.5%) were correct. The respective accuracy, sensitivity, specificity, and positive and negative predictive values were 99.6%, 100%, 98.9%, 99.3%, and 100% for diagnosis of hepatocellular carcinoma (HCC); 99.1%, 100%, 98.8%, 96.9%, and 100% for metastases; 99.6%, 100%, 99.5%, 91%, and 100% for cholangiocellular carcinomas (CCCs); all 100% for mixed HCC-CCCs; and 98.7%, 57.1%, 100%, 100%, and 98.6% for benign tumors. In view of these results, the fact that the real risks of FNB have yet to be established and the possibility that tumor seeding has a major impact on patient prognosis, the use of FNB should be drastically limited.

Color Doppler flow imaging of liver tumors.

A differential diagnosis of liver tumors was attempted on the basis of the pattern of blood flow within and around tumors on color Doppler flow images. The study comprised 35 patients with liver mass lesions: 20 patients had hepatocellular carcinoma, six had hemangiomas, four had metastatic liver cancers, one had cholangiocellular carcinoma, one had focal fatty liver, and three had liver cysts. A basket pattern (a fine blood-flow network surrounding the tumor nodule) was observed in 15 (75%) of the 20 hepatocellular carcinomas. An image of vessels within the tumor (blood flow that runs into and branches within the tumor) was observed in 13 (65%) of the 20 hepatocellular carcinomas. These two findings were observed only in hepatocellular carcinomas; even when the tumor was smaller than 2 cm in diameter, these findings were observed frequently. In the patients with multiple hepatic metastases, a "detour" pattern (a dilated portal vein meandering around the tumor nodules) was observed. In three of the six hemangiomas, a "spot" pattern (color-stained dots or patches in the central region of the tumor) was seen. Our experience suggests that hepatocellular carcinomas have a characteristic appearance on color Doppler flow images.