Differential Diagnosis of Hepatic Mass with Central Scar: Focal Nodular Hyperplasia Mimicking Fibrolamellar Hepatocellular Carcinoma

Fibrolamellar hepatocellular carcinoma is a primary hepatic tumor that usually appears in young adults. Radical surgery is considered curative for this kind of tumor, so early diagnosis becomes essential for the prognosis of the patients. The main characteristic of this entity is the central scar, which is the center of differential diagnosis. We report the case of a 30-year-old man who was diagnosed with fibrolamellar hepatocellular carcinoma by ultrasonography. Contrast-enhanced CT confirmed this diagnosis, and the patient underwent a [18F] fluorocholine PET/CT. Hypermetabolism and the morphology in the nuclear medicine exploration suggest neoplastic nature of the lesion. Radical surgery was performed, and histopathologic analysis was performed, which resulted in focal nodular hyperplasia. Hepatic masses with central scar could have a difficult differential diagnosis, and focal nodular hyperplasia could mimic fibrolamellar hepatocellular carcinoma imaging patterns. These morphofunctional characteristics have not been described in [18F] Fluorocholine PET/CT, so there is a need to find out the potential role PET/CT in the differential diagnosis of hepatic mass with central scar.

Intravitreal bevacizumab treatment for exudative choroidal neovascularisation in best vitelliform macular dystrophy

Purpose To describe results of intravitreal bevacizumab treatment of the secondary choroidal neovascularisation in Best vitelliform macular dystrophy in an adult and paediatric patient, and present the management of three asymptomatic patients with confirmed BEST1 gene mutation. Case series description Five patients from the same family with the Best vitelliform macular dystrophy are presented. In two patients (aged 63 and 4 years) secondary choroidal neovascularisation caused a rapid decline in visual acuity. In the adult patient with advanced Best vitelliform macular dystrophy, visual acuity did not improve despite eight intravitreal bevacizumab injections to the right eye. The formation of a central scar and rapid reoccurrence of choroidal neovascularisation three months after completing the initial treatment affected the outcome. As for the paediatric patient with bilateral choroidal neovascularisation in the vitelliform stage of Best vitelliform macular dystrophy, a complete recovery of visual acuity was observed after two (left eye) and three (right eye) bevacizumab injections, with adjunctive amblyopia treatment. The other three patients with an abnormal electrooculogram reported no visual problems during more than 10 years of follow-up. Minimal changes were seen on optical coherence tomography in the youngest patient. Conclusions Intravitreal bevacizumab seems to be an effective treatment for exudative choroidal neovascularisation in the vitelliform stage of Best vitelliform macular dystrophy; however, it may not be beneficial in the advanced stages of Best vitelliform macular dystrophy. It is important to regularly screen all family members with an abnormal electrooculogram and confirmed mutation for vitelliform changes and choroidal neovascularisation from an early age. The decision for anti-vascular endothelial growth factor treatment should be made on a case-to-case basis as complications may arise.

A CT-based radiomics nomogram for differentiation of renal oncocytoma and chromophobe renal cell carcinoma with a central scar-matched study

Objective: Pre-operative differentiation between renal oncocytoma (RO) and chromophobe renal cell carcinoma (chRCC) is critical due to their different clinical behavior and different clinical treatment decisions. The aim of this study was to develop and validate a CT-based radiomics nomogram for the pre-operative differentiation of RO from chRCC. Methods: A total of 141 patients (84 in training data set and 57 in external validation data set) with ROs (n = 47) or chRCCs (n = 94) were included. Radiomics features were extracted from tri-phasic enhanced-CT images. A clinical model was developed based on significant patient characteristics and CT imaging features. A radiomics signature model was developed and a radiomics score (Rad-score) was calculated. A radiomics nomogram model incorporating the Rad-score and independent clinical factors was developed by multivariate logistic regression analysis. The diagnostic performance was evaluated and validated in three models using ROC curves. Results: Twelve features from CT images were selected to develop the radiomics signature. The radiomics nomogram combining a clinical factor (segmental enhancement inversion) and radiomics signature showed an AUC value of 0.988 in the validation set. Decision curve analysis revealed that the diagnostic performance of the radiomics nomogram was better than the clinical model and the radiomics signature. Conclusions: The radiomics nomogram combining clinical factors and radiomics signature performed well for distinguishing RO from chRCC. Advances in knowledge: Differential diagnosis between renal oncocytoma (RO) and chromophobe renal cell carcinoma (chRCC) is rather difficult by conventional imaging modalities when a central scar was present. A radiomics nomogram integrated with the radiomics signature, demographics, and CT findings facilitates differentiation of RO from chRCC with improved diagnostic efficacy. The CT-based radiomics nomogram might spare unnecessary surgery for RO.

A case report of fibrolamellar hepatocellular carcinoma, with particular reference to preoperative diagnosis, value of molecular genetic diagnosis, and cell origin

Background Fibrolamellar hepatocellular carcinoma (FL-HCC) is a liver tumor that occurs almost exclusively in young adults without underlying liver disease. In spite of its distinct clinical characteristics and specific imaging findings, preoperative diagnosis is often difficult due to the extremely low incidence of the tumor. Although FL-HCC shows particular morphological features on H&E-stained tissue sections, differential diagnosis from ordinary HCC, especially the scirrhous variant of HCC, and intrahepatic cholangiocarcinoma needs additional immunohistochemical (IHC) analyses and/or molecular genetic testing. Case presentation A 21-year-old male patient was referred to our hospital for further evaluation of a large liver mass. Abdominal ultrasound examination, contrast-enhanced computed tomography, and magnetic resonance imaging revealed a well-defined hypervascular lobulated liver mass, 11 × 11 cm in diameter, with a central scar and calcification, in segments 5/8. Under the diagnosis of FL-HCC, we carried out extended anterior sectorectomy, including a part of segment 4. On microscopic examination, the tumor was composed of proliferating polygonal cells with abundant eosinophilic granular cytoplasm containing nuclei with vesicular chromatin and enlarged nucleoli, in an abundant stroma. Collagen fibers arranged in a parallel lamellar pattern were seen in the tumor stroma. These findings, together with the results of subsequent IHC analyses using HAS, CK7, and CD 67, we made the diagnosis of FL-HCC, which was further confirmed by detection of the DNAJB1-PRKACA fusion gene in the tumor cells by RT-PCR. Conclusion FL-HCC shows distinct imaging appearances. Although it also has characteristic morphological features, combined use of IHC and/or molecular genetic studies are necessary for the final diagnosis.

HBP-enhancing hepatocellular adenomas and how to discriminate them from FNH in Gd-EOB MRI

Background Recent studies provide evidence that hepatocellular adenomas (HCAs) frequently take up gadoxetic acid (Gd-EOB) during the hepatobiliary phase (HBP). The purpose of our study was to investigate how to differentiate between Gd-EOB-enhancing HCAs and focal nodular hyperplasias (FNHs). We therefore retrospectively included 40 HCAs classified as HBP Gd-EOB-enhancing lesions from a sample of 100 histopathologically proven HCAs in 65 patients. These enhancing HCAs were matched retrospectively with 28 FNH lesions (standard of reference: surgical resection). Two readers (experienced abdominal radiologists blinded to clinical data) reviewed the images evaluating morphologic features and subjectively scoring Gd-EOB uptake (25–50%, 50–75% and 75–100%) for each lesion. Quantitative lesion-to-liver enhancement was measured in arterial, portal venous (PV), transitional and HBP. Additionally, multivariate regression analyses were performed. Results Subjective scoring of intralesional Gd-EOB uptake showed the highest discriminatory accuracies (AUC: 0.848 (R#1); 0.920 (R#2)—p < 0.001) with significantly higher uptake scores assigned to FNHs (Cut-off: 75%-100%). Typical lobulation and presence of a central scar in FNH achieved an accuracy of 0.750 or higher in at least one reader (lobulation—AUC: 0.809 (R#1); 0.736 (R#2); central scar—AUC: 0.595 (R#1); 0.784 (R#2)). The multivariate regression emphasized the discriminatory power of the Gd-EOB scoring (p = 0.001/OR:22.15 (R#1) and p < 0.001/OR:99.12 (R#2). The lesion-to-liver ratio differed significantly between FNH and HCA in the PV phase and HBP (PV: 132.9 (FNH) and 110.2 (HCA), p = 0.048 and HBP: 110.3 (FNH) and 39.2 (HCA), p < 0.001)), while the difference was not significant in arterial and transitional contrast phases (p > 0.05). Conclusion Even in HBP-enhancing HCA, characterization of Gd-EOB uptake was found to provide the strongest discriminatory power in differentiating HCA from FNH. Furthermore, a lobulated appearance and a central scar are more frequently seen in FNH than in HCA.

Differential diagnosis of renal oncocytoma and chromophobe renal cell carcinoma using CT features: a central scar-matched retrospective study

Background Renal oncocytoma (RO) and chromophobe renal cell carcinoma (chRCC) have a common cellular origin and different clinical management and prognosis. Purpose To explore the utility of computed tomography (CT) in the differentiation of RO and chRCC. Material and Methods Twenty-five patients with RO and 73 patients with chRCC presenting with the central scar were included retrospectively. Two experienced radiologists independently reviewed the CT imaging features, including location, tumor size, relative density ratio, segmental enhancement inversion (SEI), necrosis, and perirenal fascia thickening, among others. Interclass correlation coefficient (ICC, for continuous variables) or Kappa coefficient test (for categorical variables) was used to determine intra-observer and inter-observer bias between the two radiologists. Results The inter- and intra-reader reproducibility of the other CT imaging parameters were nearly perfect (>0.81) except for the measurements of fat (0.662). RO differed from chRCC in the cortical or medullary side ( P = 0.005), relative density ratio ( P = 0.020), SEI ( P < 0.001), and necrosis ( P = 0.045). The logistic regression model showed that location (right kidney), hypo-density on non-enhanced CT, SEI, and perirenal fascia thickening were highly predictive of RO. The combined indicators from logistic regression model were used for ROC analysis. The area under the ROC curve was 0.923 ( P < 0.001). The sensitivity and specificity of the four factors combined for diagnosing RO were 88% and 86.3%, respectively. The correlation coefficient between necrosis and tumor size in all tumors including both of RO and chRCC was 0.584, indicating a positive correlation ( P < 0.001). Conclusion The CT imaging features of location (right kidney), hypo-density on non-enhanced CT, SEI, and perirenal fascia thickening were valuable indicators in distinguishing RO from chRCC.

Mimicker of Renal Cell Carcinoma- A Case Report

Oncocytoma is a rare epithelial tumour composed of oncocytes which are epithelial cells with excessive amount of mitochondria. The tumour is most often benign, and diagnosis can be made on the basis of histopathological examination. Here, the authors present a 64-year-old female patient, with complaints of abdominal discomfort and flank pain, along with history of loss of weight and appetite for one month. Radiology showed a left renal mass of measuring 9×7×4.5 cm involving the upper and middle pole suggestive of malignancy. Following which radical nephrectomy was done. Examination of gross specimen showed a fairly circumscribed brownish lesion in the upper and middle pole of left kidney measuring 8.8×7×4.5 cm with a central scar. There was no evidence of hilar and perirenal fat invasion. Histology showed sheets of large polygonal eosinophilic cells with centrally placed nucleus. The differentials were eosinophilic variant of clear cell renal cell carcinoma, chromophobe renal cell carcinoma and oncocytoma. A panel of Immunohistochemical (IHC) markers was performed for further categorisation and the lesional cells were positive for CD 117 and negative for CD 7 and CD 10. This ruled out the differentials and confirmed oncocytoma, thus ruling out the necessity for chemotherapy.

Imaging findings of fibrolamellar hepatocellular carcinomas on ultrasonography: A comparison with conventional hepatocellular carcinomas

BACKGROUND: Fibrolamellar hepatocellular carcinoma (FLHCC) is an unusual variant of hepatocellular carcinoma (HCC). Revealing the imaging features is important to the diagnosis of FLHCC. OBJECTIVE: The aim of this study was to investigate the imaging characteristics of FLHCCs. METHODS: This retrospective study included 29 patients with histopathologically proved FLHCC and 96 patients proved HCC. All patients underwent an ultrasound examination pre-operation. RESULTS: The average maximum diameters of the FLHCC and HCC lesions were 7.4±4.1 cm and 4.1±3.0 cm, respectively. On the ultrasound, 79.3% of the FLHCCs and 12.3% of the HCCs showed the internal hyperechoic area; 48.3% of the FLHCCs and 3.3% of the HCCs displayed a strip-like attenuation. Calcification was noted in 20.7% of the FLHCCs, while none in HCCs. On the contrast-enhanced ultrasound (CEUS), all FLHCC lesions and 87.7% of the HCCs displayed hyperenhancement in the arterial phase. An internal, unenhanced central scar appeared in all FLHCCs, while none in HCCs. CONCLUSIONS: The ultrasonographic features of FLHCC lesions indicate that they are relatively large masses showing the internal hyperechoic area or strip-like attenuation or calcification on the US and hypervascularity with an unenhanced central scar on the CEUS as compared with conventional HCC lesions.