Uncommon hepatic tumors: iconographic essay - Part 2

Primary hepatic diffuse large B-cell lymphoma presenting unusual imaging features

Primary hepatic lymphomas are frequently misdiagnosed, due to their rarity and non-specific clinical manifestations. As these tumors can be successfully treated with chemotherapy and/or radiotherapy, early recognition on imaging is essential to avoid unnecessary surgery. We report a case of primary hepatic lymphoma in a 73-year-old woman presenting with a 1-week history of persistent fever and elevated hepatobiliary enzymes. Ultrasound showed a hypoechoic hepatic mass in the anterior segment. Dynamic contrast-enhanced computed tomography (CT) revealed an ill-defined solitary mass showing peripherally dominant slight-to-moderate enhancement contrasting with a hypovascular central area. On magnetic resonance imaging, the mass showed moderate hyperintensity on T2-weighted imaging, hypointensity on T1-weighted imaging, doughnut-like hyperintensity on diffusion-weighted imaging, and an obviously low apparent diffusion coefficient (ADC). The pattern of enhancement resembled that of CT. Neither calcification nor any fat component was observed. Doughnut-like accumulation was seen on ¹⁸F-fluorodeoxyglucose (FDG)-positron emission tomography/CT without other FDG-avid lesions. Imaging findings suggested the possibility of cholangiocellular carcinoma, but the low ADC and extremely high FDG accumulation were suggestive of malignant lymphoma, and diffuse large B-cell lymphoma was pathologically confirmed from percutaneous biopsy. The mass disappeared after radiochemotherapy, and no recurrence has been observed for 3 years.

Hepatic neuroendocrine neoplasm: imaging patterns

Neuroendocrine neoplasms (NENs) are a heterogeneous group of tumors with distinct morphological and biological manifestations, the liver being the main organ affected by its metastases. However, primary hepatic involvement is quite rare. Hepatic NENs can have a variety of radiological presentation forms and can therefore mimic other lesions, making their diagnosis challenging. Nonetheless, certain imaging aspects allow NENs to be included among the main differential diagnoses of hepatic lesions and can guide the search for an extrahepatic primary site when the probable diagnosis is metastases.

MRI features of primary hepatic lymphoma

PURPOSE

Our retrospective study sought to describe the spectrum of magnetic resonance imaging (MRI) features of primary hepatic lymphoma (PHL) by analyzing its morphological aspects, signal intensity before and after contrast agent (CA) administration, and diffusion-weighted imaging (DwI) with the apparent diffusion coefficient (ADC) values.

METHODS

A retrospective analysis was conducted on 25 patients with pathologically proven PHL who underwent MRI between January 2011 and December 2016. For the evaluation of the ADC, we used a control group of 87 patients (22 with hepatocellular carcinoma, 15 with cholangiocellular carcinoma, 23 with liver metastasis, 22 with focal nodular hyperplasia, and 5 with adenoma). Two radiologists evaluated the morphological features, the signal intensity before and after CA administration, and the DwI. The sensitivity and specificity of the ADC values in distinguishing the PHL lesions from other hepatic lesions were calculated by analyzing the receiver operating characteristic (ROC) curves.

RESULTS

Twenty-one patients had non-Hodgkin's lymphoma (18 had diffuse large B-cell lymphoma and three had mucosa-associated lymphoid tissue) and four had Hodgkin's lymphoma (nodular sclerosis). The PHL had a variable morphologic distribution (17 focal mass and eight multiple nodules) and mainly an insinuative growth (24/25). Usually, PHL was usually hypointense on the T1-weighted images (23/25) and hyperintense on the T2-weighted images (21/25); non-specific dynamic enhancement was found after CA administration, but in the hepatobiliary phase, PHL is mainly hypointense (92%). All PHLs showed a signal restriction in the DwI. The sensitivity and specificity in the differential diagnosis between PHL and the other malignant lesions were respectively 81.7% and 100%, with applying an ADC cut-off value of 0.918 × 10^-3 mm²/s.

CONCLUSION

Although PHL is a rare disease and biopsy is still required, an MRI could be indicative. In our series, PHL showed an insinuative growth, hypointense signal in the hepatobiliary phase, signal restriction in the DwI, and an ADC value lower than that of the other hepatic lesions analyzed.

Analysis of the clinicopathological features and prognostic factors of primary hepatic neuroendocrine tumors

Neuroendocrine tumors (NETs) of the gastrointestinal tract often spread to the liver, while primary hepatic NETs (PHNETs), first described by Edmondson in 1958, are very rare. The majority of existing reports regarding PHNETs have small sample sizes, and the clinicopathological characteristics and prognostic factors are still unclear. The aim of the present study was to analyze the clinicopathological features and explore the prognostic factors of PHNETs. From March 2012 to March 2017, 28 cases of PHNETs were retrospectively evaluated to analyze the clinicopathological features and explore the prognostic factors of PHNETs. The 28 PHNETs patients were males (n=15) and females (n=13) aged between 32 and 76 years (mean=53 years). Among them, 16 patients had clinical symptoms. The remaining 12 patients had no obvious clinical symptoms, only hepatoncus was observed during physical examination. Single-factor analysis showed that carbohydrate antigen 125 (CA125), alanine aminotransferase (ALT), aspartate aminotransferase (AST), hemoglobin (HB), Ki-67 positive index (PI), surgical treatment and pathological grading were correlated to PHNET prognosis (P<0.05); multifactor analysis revealed that Ki-67 PI was associated with the prognosis (P<0.05). Thus, the prognosis of PHNETs may be effectively predicted using the indexes of CA125, ALT, AST, HB, Ki-67 PI, pathological grading and surgical treatment. Pathological classification of grade 3, high expression of Ki-67 PI, abnormal elevation of CA125, abnormalities of ALT and AST, anemia and lack of radical operation indicated a poor prognosis. High expression of Ki-67 PI was an independent prognostic factor for PHNETs.

Acquired portosystemic collaterals: anatomy and imaging

Portosystemic shunts are enlarged vessels that form collateral pathological pathways between the splanchnic circulation and the systemic circulation. Although their causes are multifactorial, portosystemic shunts all have one mechanism in common-increased portal venous pressure, which diverts the blood flow from the gastrointestinal tract to the systemic circulation. Congenital and acquired collateral pathways have both been described in the literature. The aim of this pictorial essay was to discuss the distinct anatomic and imaging features of portosystemic shunts, as well as to provide a robust method of differentiating between acquired portosystemic shunts and similar pathologies, through the use of illustrations and schematic drawings. Imaging of portosystemic shunts provides subclinical markers of increased portal venous pressure. Therefore, radiologists play a crucial role in the identification of portosystemic shunts. Early detection of portosystemic shunts can allow ample time to perform endovascular shunt operations, which can relieve portal hypertension and prevent acute or chronic complications in at-risk patient populations.

Prevalence and sonographic changes compatible with fatty liver disease in patients referred for abdominal ultrasound examination in Aracaju, SE

Objective

To estimate the prevalence and evaluate sonographic findings compatible with changes consistent with hepatic steatosis in patients referred for abdominal ultrasonography at four reference centers in Aracaju, SE, Brazil.

Materials and Methods

Prospective, descriptive survey, with analytical and quantitative approach, comprising abdominal ultrasonography scans performed with a convex, dynamic 3.75 MHz transducer. Liver dimensions and parenchymal echotexture were evaluated, classifying hepatic steatosis into grades (1, 2 or 3). The SPSS^® 22.0 software was used for statistical analysis, adopting p < 0.05 as significance level.

Results

A total of 800 individuals (561 women and 239 men) were evaluated. The prevalence of steatosis was 29.1%, and the male patients were most affected, presenting with more advanced grades of disease (p = 0.021), as follows: 119 grade 1 (51.0%); 94 grade 2 (40.4%); and 20 grade 3 (8.6%). The median age patients' was 46 years.

Conclusion

In the present study sample, the prevalence of hepatic steatosis was high, particularly in the male patients. Ultrasonography is suggested as a first choice for the diagnosis of this condition, considering its wide availability, low cost and absence of side effects or risks to the patient.