Epithelioid angiomyolipoma of the liver: CT and MRI features

Unveiling the mystery of hepatic epithelioid angiomyolipoma: A unique case report with literature review

Hepatic epithelioid angiomyolipoma is a rare mesenchymal liver tumor within the perivascular epithelioid cell tumor family, known for its uncertain malignancy and potential for aggressive behavior. Clinical presentation, laboratory findings, and imaging results lack specificity, making pathological examination critical for definitive diagnosis. This case report presents a 61-year-old male patient with a single tumor in the right liver lobe, measuring approximately 101 mm × 99 mm. Initial imaging misdiagnosed the mass as hepatocellular carcinoma. Following multidisciplinary treatment discussions and subsequent tumor resection, histopathology and immunohistochemistry confirmed hepatic epithelioid angiomyolipoma. Accurate diagnosis of hepatic epithelioid angiomyolipoma is challenging, relying on histopathological examination and immunohistochemistry as diagnostic standards. Continuous monitoring of patients with hepatic epithelioid angiomyolipoma over an extended period is deemed essential. This report highlights the positive impact of multidisciplinary treatment in diagnosing and managing hepatic epithelioid angiomyolipoma.

Ceus features of liver pecoma: a case report and literature review

Perivascular epithelioid cell neoplasms (PEComas) and epithelioid angiomyolipomas (EAMLs) are two different denominations for the same "mesenchymal tumor composed of histologically and immunohistochemically distinctive perivascular epithelioid cells". Hepatic PEComa/EAML is a very rare neoplasm, and only 29 case reports of hepatic PEComa and 25 of hepatic EAML have been reported in the current literature. A clear female predominance with a mean age at diagnosis of 42.5 years old can be observed by literature review. Ultrasound (US) examination was the first-line diagnostic technique in most of the cases of hepatic PEComa, but it was documented in very few cases of hepatic EAML. A great variability in the ultrasonographic B-mode, color Doppler and contrast-enhanced ultrasonography (CEUS) features of hepatic PEComa/EAML emerges. Computed tomography and magnetic resonance were the most common used techniques to confirm the nature of the hepatic lesion, even if the anatomo-pathological examination was the only technique to display a certainty diagnosis and to differentiate hepatic PEComa/EAML from benign and malignant hepatic lesions. The great majority of hepatic PEComas/EAMLs are surgically treated without any adjuvant therapy.

Fat-Poor Hepatic Angiomyolipoma in Noncirrhotic Livers: Imaging Features, Pathology, and Differential Diagnosis

OBJECTIVE

To investigate imaging features of fat-poor hepatic angiomyolipomas in noncirrhotic livers in order to enhance the diagnostic accuracy for this condition.

METHODS

The clinical and imaging data of 19 patients with fat-poor hepatic angiomyolipoma (fpHAML) was retrospectively analyzed.

RESULTS

Of the 19 patients without hepatitis, cirrhosis, or sarcoidosis, 16 had no clinical symptoms. There were 20 lesions in 19 patients. Macroscopic fat, calcification, hemorrhage, necrosis, and pseudocapsule were not observed in the 20 lesions. All lesions showed marked enhancement on the arterial phase, and the degree of enhancement was significantly higher than that in the adjacent hepatic parenchyma. In 8 cases, the enhancement of the portal phase was higher than that in the arterial phase. Multiple intratumor vessels were observed in the tumor, and lesions with diameters larger than 3.0 cm were more frequently observed. The degree of enhancement of 18 lesions on portal phase or delayed phase was slightly higher than or equal to that in the surrounding hepatic parenchyma. The lesions were hyperintense on diffusion-weighted imaging and showed homogeneous hypointensity on the hepatobiliary phase. Only 6 cases showed the presence of an early draining vein.

CONCLUSIONS

These imaging features have some implications for the diagnosis of fpHAML. Therefore, an increased awareness of fpHAML is needed among radiologists.

Hepatic Angiomyolipoma in Patients With Inflammatory Breast Cancer: A Case Report

Hepatic angiomyolipoma (HAML) is a rare tumor comprising adipose tissue, smooth muscle cells, and blood vessels. On the other hand, inflammatory breast cancer (IBC) is a rare and severe form of breast cancer that progresses quickly and presents as breast inflammation. It is incredibly unusual for HAML and IBC to coexist in the same patient. In the present study, we describe a case of a 63-year-old Yemeni female patient diagnosed with locally advanced left breast cancer presented with pain at the left breast and axilla. A computed tomography (CT) scan for staging showed an incidental large hepatic mass, which was eventually discovered to be HAML. The patient underwent a modified radical mastectomy after completing her neoadjuvant treatment and later underwent parenchyma-sparing liver resection of that lesion; follow-up has continued till now. The diagnosis of HAML in the presence of IBC can pose challenges due to overlapping clinical and radiological features. Treatment decisions for patients with coexisting HAML and IBC require a multidisciplinary approach; surgical resection, embolization, targeted therapies, and systemic chemotherapy may be considered based on the extent of the disease and individual patient factors. Lastly, a brief review of the related literature was also carried out.

Hepatic epithelioid angiomyolipoma is scattered and unsuitable for surgery: a case report

Hepatic epithelioid angiomyolipoma (HEAML) is a rare tumour of mesenchymal tissue with a malignant tendency. Occurring most frequently in women, the relative incidence in men and women, according to incomplete statistics, is approximately 1:5. In rare cases, disease occurrence and development is hidden. Lesions are generally discovered as chance findings by patients; abdominal pain is the first symptom, and imaging has no specificity in diagnosing the disease. Therefore, great difficulties exist in the diagnosis and treatment of HEAML. Here, the case of a 51-year-old female patient with a history of hepatitis B, and abdominal pain over 8 months as the initial symptom, is described. The patient was found to have multiple intrahepatic angiomyolipoma. Due to the small and scattered foci, complete resection was impossible, and because of her history of hepatitis B, conservative treatment was undertaken, with the patient undergoing regular follow-up. When hepatic cell carcinoma could not be excluded, the patient was treated with transcatheter arterial chemoembolization. No tumour neogenesis or metastasis was detected at the 1-year follow-up.

Perivascular epithelioid cell tumors of the liver misdiagnosed as hepatocellular carcinoma: Three case reports

BACKGROUND

Hepatic perivascular epithelioid cell neoplasms (PEComas) are rare. Diagnostic and treatment experience with hepatic PEComa remains insufficient.

CASE SUMMARY

Three hepatic PEComa cases are reported in this paper: One case of primary malignant hepatic PEComa, one case of benign hepatic PEComa, and one case of hepatic PEComa with an ovarian mature cystic teratoma. During preoperative imaging and pathological assessment of intraoperative frozen samples, patients were diagnosed with hepatocellular carcinoma (HCC), while postoperative pathology and immunohistochemistry subsequently revealed hepatic PEComa. Patients with hepatic PEComa which is misdiagnosed as HCC often require a wider surgical resection. It is easy to mistake them for distant metastases of hepatic PEComa and misdiagnosed as HCC, especially when it's combined with tumors in other organs. Three patients eventually underwent partial hepatectomy. After 1-4 years of follow-up, none of the patients experienced recurrence or metastases.

CONCLUSION

A clear preoperative diagnosis of hepatic PEComa can reduce the scope of resection and prevent unnecessary injuries during surgery.

Hepatic steatosis with mass effect: A case report

BACKGROUND

Hepatic steatosis is a common radiologic finding. Some imaging inklings are the absence of a mass effect, and there is currently no report of hepatic steatosis with mass effect.

CASE SUMMARY

A 23-year-old female was admitted due to a liver mass for half a month. No obvious abnormalities were found in physical and laboratory examinations. Ultrasound, computed tomography, and magnetic resonance imaging showed a huge mass between the liver and stomach with a significant mass effect, and the caudate lobe and left lobe of the liver were involved. The signal on T2- and T1- weighted fat-saturated images of the mass was significantly reduced, and the enhanced scan showed inhomogeneous enhancement. Surgical and pathological findings indicated the diagnosis of hepatic steatosis. The operation and re-review of the patient's images showed that the lesion was supplied by the branch of the hepatic artery. The signal on T1-weighted out-of-phase images of the lesion was lower than on in-phase images, and there was no black rim cancellation artifact around the hepatic steatosis area on T1-weighted out-of-phase images. The dynamic enhancement pattern of the lesion was similar to that of the adjacent normal liver parenchyma. The above characteristics suggested that the lesion was hepatic steatosis. However, in this case, the lesion showed exogenous growth and was mass-like, with an obvious mass effect, which has not been reported previously.

CONCLUSION

Hepatic steatosis could grow exogenously and has an obvious mass effect. It needs to be distinguished from fat-rich tumors. The T1-weighted in- and out-of-phase images and dynamic enhanced scanning are valuable for differential diagnosis of this lesion.

Case report: Hepatic epithelioid angiomyolipoma with elevated alpha-fetoprotein and a history of breast cancer

Background

Perivascular epithelioid cell tumors have characteristic histological and immunohistochemical profiles. Epithelioid angiomyolipomas in the liver have particularly rare characteristics. These tumors are relatively small and lack clinical and imaging specificity. Thus, they can be easily misdiagnosed as other primary or metastatic tumors prior to surgery. Due to the significant epithelioid morphology and atypia of hepatic epithelioid angiomyolipoma (HEAML), intraoperative frozen section pathologic diagnosis might be challenging.

Case presentation

A 33-year-old woman was admitted to our hospital for elevated alpha-fetoprotein (AFP) levels after a regular checkup following breast cancer surgery. Initially, liver cancer was suspected based on enhanced magnetic resonance imaging and color Doppler ultrasonography. Her serum AFP levels were 23.05 ng/ml. The patient underwent laparoscopic right hepatic tumor resection. Based on intraoperative cryopathology, hepatocellular carcinoma was considered a likely diagnosis. However, postoperative pathology confirmed a right HEAML. The patient underwent regular checkups for 23 months without exhibiting recurrence or distant metastasis.

Conclusion

HEAML can be easily misdiagnosed on preoperative imaging and intraoperative cryopathology. Medical professionals must be aware of this possibility and proceed with caution. Postoperative pathological examination with assessment of IHC markers was helpful in diagnosing HEAML. HEAML has low malignant potential. Surgical resection is the mainstay of treatment, and most patients have a good prognosis.

Baseline and contrast-enhanced ultrasound features of hepatic epithelioid angiomyolipoma

BACKGROUND

Recurrence or metastasis after surgery had been reported in hepatic epithelioid angiomylipoma (epi-AML). Most hepatic epi-AMLs were misdiagnosed with hepatocellular carcinoma or other hepatic tumors before surgery.

OBJECTIVE

To describe the baseline and contrast-enhanced ultrasound (CEUS) features of hepatic epi-AMLs and to explore the potential ultrasonic features for prognosis.

METHODS

The retrospective study enrolled 67 patients (56 females, 11 males) with 67 pathologically confirmed hepatic epi-AML lesions. All the lesions were examined by baseline ultrasound and 42 lesions were examined using CEUS with SonoVue (Bracco, Milan, Italy) before surgery.

RESULTS

Baseline ultrasound features of hepatic epi-AMLs included heterogeneous echo (86.6%), well-defined border (68.7%), hypoecho (64.2%), regular morphology (62.7%), peripheral-tumor arc-shaped or ring-like vessels (53.7%), and low value of resistive index (0.51±0.08). CEUS features of hepatic epi-AMLs included arterial phase hyper-enhancement with smooth and well-defined margin (100%), peripheral-tumor ring-like vessels (57.1%), and intra-tumor vessels (52.4%). Some CEUS features, including arterial phase heterogeneously tortuous filling, intra-tumor vessels and peripheral-tumor ring-like vessels were more commonly found in hepatic epi-AMLs of uncertain malignant potential/malignant than in benign hepatic epi-AMLs (p <  0.05).

CONCLUSIONS

Baseline ultrasound and CEUS features may be useful in diagnosis of hepatic epi-AML, and some CEUS features may be indicative of its malignant potential.

Clinicopathological correlation and post-resection outcomes of hepatic angiomyolipoma

Backgrounds/Aims

Angiomyolipoma is a rare neoplasm of mesenchymal origin derived from perivascular epithelioid cells. Due to rarity, hepatic angiomyolipoma (HAML) has been often misdiagnosed as hepatocellular carcinoma (HCC) or other hypervascular liver tumors based on imaging studies. This study investigated the clinicopathological correlation and post-resection outcomes of HAML.

Methods

This retrospective observational study included 40 patients who underwent hepatic resection (HR) for HAML between 2008 and 2018.

Results

Mean age of the patients was 42.6±11.4 years and there were 30 (75.0%) females. Hepatitis B and C virus infection was present in 8 patients (20.0%) and 1 patient (2.5%), respectively. Preoperative diagnoses on imaging studies were HCC in 23 (57.5%) patients, HAML in 14 (35.0%) patients, focal nodular hyperplasia in 2 (5.0%) patients, and hepatic adenoma in 1 (2.5%) patient. Percutaneous liver biopsy was performed in 10 (25.0%) patients and HAML was diagnosed in all patients. Only 3 patients (7.5%) showed a slight elevation in the level of liver tumor markers. Major HR was performed in 10 (25.0%). Laparoscopic HR was performed in 9 (22.5%). The mean tumor size was 4.8±3.9 cm and single tumor was present in 38 (95.0%) patients. Currently, all the patients are alive without tumor recurrence during the follow-up observation period of 75.7±37.3 months.

Conclusions

HAML is a rare form of primary liver tumor and is often misdiagnosed as HCC or other hypervascular tumors. Although HAML is benign in nature, it has malignant potential, thus resection is indicated if the tumor grows or malignancy cannot be excluded.

Differentiating Hepatic Epithelioid Angiomyolipoma From Hepatocellular Carcinoma and Focal Nodular Hyperplasia via Radiomics Models

Background: We conduct a study in developing and validating two radiomics-based models to preoperatively distinguish hepatic epithelioid angiomyolipoma (HEAML) from hepatic carcinoma (HCC) as well as focal nodular hyperplasia (FNH).

Methods: Totally, preoperative contrast-enhanced computed tomography (CT) data of 170 patients and preoperative contrast-enhanced magnetic resonance imaging (MRI) data of 137 patients were enrolled in this study. Quantitative texture features and wavelet features were extracted from the regions of interest (ROIs) of each patient imaging data. Then two radiomics signatures were constructed based on CT and MRI radiomics features, respectively, using the random forest (RF) algorithm. By integrating radiomics signatures with clinical characteristics, two radiomics-based fusion models were established through multivariate linear regression and 10-fold cross-validation. Finally, two diagnostic nomograms were built to facilitate the clinical application of the fusion models.

Results: The radiomics signatures based on the RF algorithm achieved the optimal predictive performance in both CT and MRI data. The area under the receiver operating characteristic curves (AUCs) reached 0.996, 0.879, 0.999, and 0.925 for the training as well as test cohort from CT and MRI data, respectively. Then, two fusion models simultaneously integrated clinical characteristics achieved average AUCs of 0.966 (CT data) and 0.971 (MRI data) with 10-fold cross-validation. Through decision curve analysis, the fusion models were proved to be excellent models to distinguish HEAML from HCC and FNH in comparison between the clinical models and radiomics signatures.

Conclusions: Two radiomics-based models derived from CT and MRI images, respectively, performed well in distinguishing HEAML from HCC and FNH and might be potential diagnostic tools to formulate individualized treatment strategies.

Evaluation of Primary Liver Cancers Using Hepatocyte-Specific Contrast-Enhanced MRI: Pitfalls and Potential Tips

When radiologists interpret hepatic focal lesions seen on dynamic magnetic resonance imaging (MRI) scans, it is important not only to distinguish malignant lesions from benign ones but also to distinguish nonhepatocellular carcinoma (HCC) malignancies from HCCs. In addition, most major guidelines, including those of the American Association for the Study of Liver Disease, European Association for the Study of the Liver, and Korean Liver Cancer Association and National Cancer Center, allow for the noninvasive imaging diagnosis of HCC in at-risk patients. However, ~40% of HCC cases show atypical imaging features mimicking non-HCC malignancies. Furthermore, several benign and malignant lesions, such as flash-filling hemangioma and intrahepatic mass-forming cholangiocarcinoma, frequently look like HCC. In contrast, although multiparametric MRI options, including hepatobiliary phase and diffusion-weighted imaging, provide useful information that could help address these challenges, there remain several unresolved issues with regard to the noninvasive diagnostic criteria characterizing HCC. In this article, we discuss the typical imaging features and challenging situations related to primary liver cancers in MRI, while considering how to make a correct diagnosis. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY STAGE: 3.

Comparison of hepatic epithelioid angiomyolipoma and non-hepatitis B, non-hepatitis C hepatocellular carcinoma on contrast-enhanced ultrasound

PURPOSE

The purpose of this study was to retrospectively compare the imaging features of hepatic epithelioid angiomyolipoma (HEAML) to those of hepatocellular carcinoma negative for hepatitis B surface antigen and hepatitis C antibody (NBNC-HCC) on contrast-enhanced ultrasound (CEUS) with sulphur hexafluoride microbubbles.

MATERIAL AND METHODS

Twenty-two patients (4 men, 18 women) with a mean age of 42.6±10.2 (SD) years (range: 22-63 years) with histopathologically confirmed HEMAL were included in the study. Forty-four patients (30 men, 14 women) with a mean age of 57.3±15.9 years (range: 19-85 years) with histopathologically confirmed NBNC-HCC were randomly selected from our institution's database as a control group. The CEUS characteristics of the two groups were compared.

RESULTS

On conventional ultrasound, significant differences in tumor diameter were found between HEAML (4.0±2.0 [SD] cm; range: 1.3-8.9cm) and NBNC-HCC (8.4±4.4 [SD] cm; range: 1.6-18cm) (P<0.001) as well as in degrees of enhancement during the portal (P=0.001) and late phases (P=0.003), contrast distribution (P<0.001) and absence of pseudocaspule (P<0.001). On CEUS, hyperenhancement during the arterial phase was observed in 21/22 (95.5%) HEAMLs and in 43/44 (97.7%) NBNC-HCCs (P>0.999). Homogeneous enhancement was more frequent in HEAMLs (20/22; 90.9%) than in NBNC-HCCs (13/44; 29.6%) (P<0.001). Pseudocapsule was observed in 0/22 HEAMLs (0.0%) and in 36/44 NBNC-HCCs (81.8%) (P=0.017). A prolonged enhancement was observed in 5/22 HEAMLs (22.7%) and in 0/44 NBNC-HCCs (0.0%) (P<0.001) during the late phase.

CONCLUSION

CEUS with sulphur hexafluoride microbubbles is helpful in discriminating between HEAML and NBNC-HCC. Homogeneous enhancement and lack of pseudocapsule are suggestive features for the diagnosis of HEAML.

Imaging hepatic angiomyolipomas: key features and avoiding errors

Hepatic angiomyolipomas (HAMLs) are rare mesenchymal neoplasms, which have highly variable imaging appearances, often leading to misdiagnosis. They belong to the family of perivascular epithelioid cell neoplasms (PEComas). HAMLs have a wide spectrum of imaging appearances due to variable amounts of smooth muscle cells, adipose tissue, and blood vessels in their makeup. Although typically sporadic, they are also associated with tuberous sclerosis. Sporadic lesions tend to be solitary whilst patients with tuberous sclerosis often have multiple HAMLs invariably accompanied by renal AMLs. Having been originally considered benign hamartomas, increasing reports of complications, including malignant behaviour, has also resulted in uncertainty in regard to their optimal management. Typically described imaging characteristics are of a hypervascular fat-containing lesion with prominent intratumoural vessels and an early draining vein; however HAMLs commonly demonstrate a paucity of fat or wash-out on contrast-enhanced imaging, and not all HAML lesions are hypervascular. HAMLs can therefore easily be misdiagnosed as other hepatic lesions, in particular hepatocellular carcinoma. This review describes the imaging characteristics of HAMLs, illustrating the wide variety of potential appearances across ultrasound, contrast-enhanced ultrasound, computed tomography, and magnetic resonance imaging, and highlights the challenges and potential errors that can be made. This review will aid radiologists in avoiding potentially major pitfalls when faced with this rare but important liver pathology.

Two case reports and literature review for hepatic epithelioid angiomyolipoma: Pitfall of misdiagnosis

BACKGROUND

Hepatic epithelioid angiomyolipoma (HEAML) is a rare liver disease and is easily misdiagnosed. Enhanced recognition of HEAML is beneficial to the differential diagnosis of rare liver diseases.

CASE SUMMARY

We presented two cases of HEAML in Changzheng Hospital, Naval Medical University, and then collected and analyzed all reports about HEAML recorded in PubMed, MEDLINE, China Science Periodical Database, and VIP database from January 2000 to March 2018. A total of 409 cases of HEAML in 97 reports were collected, with a ratio of men to women of 1:4.84 and an age range from 12 years to 80 years (median 44 years). Among the patients with clinical symptoms mentioned, 61.93% (205/331) were asymptomatic, 34.74% (115/331) showed upper or right upper quadrant abdomen discomfort, while a few of them showed abdominal mass, gastrointestinal symptoms, low fever, or weight loss. The misdiagnosis rate of HEAML was as high as 40.34% (165/409) due to its nonspecific imaging findings. Most of the tumors were solitary and round in morphology, with clear boundaries. Ultrasound scan indicated low echo with internal nonuniformity and rich blood supply in most cases. Computer tomography/magnetic resonance imaging enhanced scan showed varied characteristics. The ratio of fast wash-in and fast wash-out, fast wash-in and slow wash-out, and delayed enhancement was roughly 4:5:1. A definite diagnosis of HEAML depended on the pathological findings of the epithelioid cells in lesions and the expression of human melanoma black 45, smooth muscle actin, melanoma antigen, and actin by immunohistochemical staining. HEAML had a relatively low malignant rate of 3.91%. However, surgical resection was the main treatment for HEAML, due to the difficulty diagnosing before operation.

CONCLUSION

HEAML is a rare and easily misdiagnosed disease, and it should be diagnosed carefully, taking into account clinical course, imaging, pathological ,and immunohistochemical findings.

Comparison of MRI Features of Epithelioid Hepatic Angiomyolipoma and Hepatocellular Carcinoma: Imaging Data From Two Centers

Introduction: Epithelioid hepatic angiomyolipoma (Epi-HAML) can easily be misdiagnosed as a malignant tumor such as hepatocellular carcinoma (HCC) because of the low-fat content on imaging. We analyzed and compared the magnetic resonance imaging (MRI) features of Epi-HAML and HCC, which would aid in disease diagnosis.

Methods: We included 30 pathologically confirmed patients with Epi-HAML and 80 with HCC, who underwent both MRI unenhanced scan and three-phase contrast-enhanced MRI scan. The clinical and MRI features of the two groups were summarized and analyzed.

Results: Epi-HAML showed significant differences compared to HCC group in terms of clinical features such as sex preference, age, concomitant diseases (hepatitis B and cirrhosis), and elevated plasma alpha-fetoprotein (AFP) (P < 0.001). In addition, there were statistically significant differences between both tumor types with regard to conventional MRI findings such as a solitary tumor (100 vs. 83.8%, P = 0.018), well-defined (93.3 vs. 71.3%, P = 0.027), mild hyperintensity (40.0 vs. 3.7%, P < 0.001) on DWI with high b-value, fat within the tumor (43.3 vs. 8.8%, P < 0.001), and rare necrosis (3.3 vs. 26.3%, P = 0.016). Besides, Epi-HAML displayed significant differences compared to HCC in terms of contrast-enhanced MRI characteristics such as draining hepatic vein (30.0 vs. 3.8%, P < 0.001), portal vein tumor thrombus (0 vs. 13.8%, P = 0.033), hypointensity at delayed phase (70.0 vs. 95%, P = 0.001), intra-tumor vessel at delayed phase (36.7 vs. 10.0%, P = 0.003), pseudocapsule (20.0 vs. 78.8%, P < 0.001), and prolonged enhancement (56.7 vs. 1.2%, P < 0.001).

Conclusion: Epi-HAML frequently occurs in middle-aged women and usually lacks characteristic clinical symptoms. Typically, Epi-HAML presents as an isolated and well-defined tumor with rich vasculature. Specific MRI features such as intra-tumor fat, intra-tumor vessel, draining hepatic vein, prolonged enhancement, and lack of capsule may contribute to a more confident diagnosis of Epi-HAML.

CT features of hepatic epithelioid angiomyolipoma: differentiation from hepatocellular carcinoma in patients with noncirrhotic livers

Background

Hepatic epithelioid angiomyolipoma (HEA) shares some similarities with other hepatic tumors, such as hepatocellular carcinoma (HCC). Thus, establishing a definite diagnosis of HEA based on medical imaging is often difficult. In this study, we evaluated multiphasic computed tomography (CT) imaging to differentiate HEA from HCC in patients with noncirrhotic livers.

Methods

We retrospectively analyzed the clinical and imaging data of both contrast and non-contrast enhanced CT scans from 25 patients with HEA and 50 patients with HCC in noncirrhotic livers. CT features, including lesion position, size, shape, interior content, border, enhancement degree, and enhancement pattern, were independently evaluated by two radiologists. Intratumoral blood vessels, peripheral supply vessels, the early display of the hepatic vein, peripheral abnormal perfusion, peripheral washout sign, pseudocapsule, and portal tumor thrombus were also evaluated. Next, we quantitatively analyzed difference within results of clinical and CT characteristics between the HEA and HCC groups.

Results

The number of female HEA patients is more than male (76% vs. 24%), with a mean age of 49.44±10.33 years (from 30 to 68 years). The majority (64%) of HEA patients were asymptomatic, without hepatitis (88%). On non-contrast enhanced CT, HEA mainly manifested as a round (92%), hypodense mass (100%) with little fat (12%) and rare complications, such as hemorrhage (4%) and calcification (4%). HEA all manifested as an intensely enhanced mass on contrast-enhanced CT. The differences between HEA and HCC were significant in the imaging characteristics of the early display of the hepatic vein (32% vs. 0%, P=0.000), intratumoral blood vessels during the nonarterial phase (36% vs. 8%, P=0.003), washout enhancement (52% vs. 86%, P=0.001), and prolonged enhancement (40% vs. 4%, P=0.000).

Conclusions

Although HEA is an uncommon hepatic tumor, clinical and CT manifestation may be indicative. Clinical and CT characteristics including asymptomatic, non-hepatic, fat-deficient, early display of the hepatic vein, intratumoral blood vessels during the nonarterial phase and prolonged enhancement are selected to improve the recognition of HEA, supporting for a differential diagnosis from HCC.

Hepatic epithelioid angiomyolipoma with renal metastasis: radiologic-pathologic correlation

Epithelioid angiomyolipoma (EAML) is a rare subtype of angiomyolipomas. Unlike the conventional angiomyolipomas, EAML often contains minimal fat which usually precludes prospective diagnosis on imaging. The imaging findings of EAML may overlap with other benign and malignant hepatic neoplasms. We report a hepatic epithelioid angiomyolipoma in a 47-year-old female which metastasized to the right kidney and recurred after resection in the liver. We analyze the imaging findings of EAML on ultrasound, computed tomography, positron emission tomography and magnetic resonance imaging. Correlation between the imaging and histopathologic findings is made. The estimated annual growth and doubling time of the primary hepatic EAML are calculated. To the best of our knowledge, this is the first published report of positron emission tomography–computed tomography findings and annual growth rate for hepatic EAML.

Malignant potential of epithelioid angiomyolipomas of the liver: A case report and comprehensive review of the literature

Hepatic epithelioid angiomyolipoma (HEAML) is a rare mesenchymal tumor that has been reported to have malignant potential. We herein describe a rare case of atypical HEAML. A 43-year-old Caucasian male patient visited his general practitioner due to a productive cough persisting for >2 months. During evaluation with several imaging tests, a chest computed tomography (CT) incidentally revealed a well-demarcated lesion in the caudate lobe of the liver, sized 7 cm. An abdominal magnetic resonance imaging examination confirmed the findings of the CT. The possibility of hepatocellular carcinoma at that time could not be excluded. Due to inconclusive cross-sectional imaging, the patient underwent left hepatectomy with additional resection of segment I. The patient's postoperative course was uneventful. A diagnosis of 'atypical' HEAML was established in the present case. The majority of HEAMLs are considered to be benign, although there are several reported cases exhibiting malignant behavior, such as tumor growth, presence of atypical cells, recurrence after surgical resection, metastasis and invasive growth into the liver parenchyma and alongside the vessels. From 2000 onwards, 19 cases of malignant hepatic AML have been reported. Malignant transformation is considered to occur mostly in the epithelioid subtype. To that end, when epithelioid or atypical characteristics are identified on preoperative biopsy, resection is indicated due to the high probability of malignancy.

Hepatic epithelioid angiomyolipoma: a report of two cases and review of the literature

Hepatic epithelioid angiomyolipoma (EAML) is an uncommon mesenchymal tumor with malignant potential, which is clinically susceptible to being misdiagnosed as hepatocellular carcinoma. Therefore, accurate diagnosis of hepatic EAML and treatment is necessary. We report two cases of hepatic EAML that were identified by abdominal computed tomography (CT). The first case presented in a 37-year-old woman and was an oval-shaped liver mass, measuring 4.5×4.2×4.9 cm. The second case presented in a 51-year-old woman and was a round-shaped mass measuring 4×3.5×3.7 cm. Both patients underwent laparoscopic resection. Microscopically, we detected epithelioid and spindle-shaped cells with adipocytes. After the analysis of biomarkers, we found that both cases were positive for HMB45 and Melan-A, which helped to confirm the diagnosis. Hepatic EAML is a rare clinical tumor, which has a high rate of misdiagnosis and the final diagnosis depends on histopathologic and immunohistochemical features. Laparoscopic resection remains the recommended choice for hepatic EAML. Partial hepatic EAML has a tendency become malignant and thus long-term follow-up is needed.

Unresectable hepatic PEComa: a rare malignancy treated with stereotactic body radiation therapy (SBRT) followed by complete resection

BACKGROUND

Perivascular epithelioid cell tumors (PEComas) are rare mesenchymal tumors occurring in various anatomic regions. Although diagnostic criteria and treatment management are not established, current treatment options consist of surgery and chemotherapy including mTOR inhibitors. Stereotactic body radiation therapy (SBRT) is a non-invasive ablative treatment which has shown excellent control rates for more common types of unresectable liver tumors and metastases. In this report we present a rare case of PEComa of the liver that was treated by stereotactic radiotherapy followed by resection. Staging and evaluation of treatment response was done by FDG-PET/CT. This case highlights the potential of SBRT as a neoadjuvant treatment even for rare liver malignancies. It is the first case of liver PEComa treated by SBRT and resection.

CASE PRESENTATION

A 52-year-old woman presented at an external hospital with abdominal pressure and pain in the right upper abdominal quadrant. A CT scan showed a 700 cm3 liver lesion in segment IV. In repeated biopsy in July 2015 histopathological workup showed a pleomorphic epitheloid tumor with small to medium sized cells expressing vimentin and melan-A while being negative for cytokeratin establishing the diagnosis of PEComa of the liver. To achieve high, ablative doses a stereotactic body radiotherapy (SBRT) technique was chosen consisting of 60Gy (biologically effective dose 105Gy) in 8 fractions of 7.5Gy. Radiotherapy planning was based on MRI resulting in a planning target volume (PTV) of 1944 cm3. Treatment toxicity was limited to a slight elevation of transaminases (grade 1 and 3). A complete resection was performed 21 weeks after radiotherapy confirmed by negative surgical margins. At last follow-up 21 months after therapy, MRI showed neither local nor distant tumor recurrence. The patient was in stable condition (ECOG 1) and without late radiation toxicity.

CONCLUSIONS

This is the first documented case of liver PEComa treated by SBRT and resection. A favorable post-treatment course demonstrates that SBRT is a potential neoadjuvant treatment that is capable of reducing an inoperable rare liver tumor to a resectable lesion.

Imaging appearance of renal epithelioid angiomyolipoma: A case report and literature review

RATIONALE

Epithelioid angiomyolipoma (EAML) is an extremely rare disease. It commonly occurs in middle-aged females and mainly involves the kidney. Histological and immunohistochemical examination play important roles in differentiating EAML from renal cell carcinoma (RCC) and poor-fat angiomyolipoma (AML).

PATIENT CONCERNS

Here, We report the imaging phenotype, as well as the pathological findings of a case of EAML in a 39-year-old female.

DIAGNOSES

Preoperative noncontrast computed tomography (CT) scan revealed a 6.0 × 5.2 × 7.0 cm soft tissue mass with necrosis, located in the left kidney. On contrast-enhanced CT images, aprogressive enhancement pattern was observed. CT angiography did not show any enlarged vessels or vascular malformation. Abdominal MRI showed a well-circumscribed solid mass with a heterogeneous signal on T1-weighted and T2-weighted images. Ultrasonography of the abdomen demonstrated a hypoechoic mass with abundant blood flow. This patient underwent radical nephrectomy. The pathologic diagnosis was EAML.

INTERVENTIONS

This patient underwent operative resection of the tumor. The resection margins were negative for the neoplastic proliferation and no distant metastases were found. The patient did not receive advanced radiotherapy or chemotherapy.

OUTCOMES

Four months after surgery, the follow-up CT scan did not reveal any local recurrence or distant metastases.

LESSONS

This case adds to the experience with EAML by summarizing its imaging characteristics as well as reviewing the literature. Additionally, we described the state-of-the-art management of the management of this rare tumor.

Fat-Containing Liver Lesions on Imaging: Detection and Differential Diagnosis

OBJECTIVE

The purpose of this article is to review how fat is detected on imaging and to discuss the differential diagnosis of fat-containing liver lesions.

CONCLUSION

Fat is a highly useful feature in characterizing liver lesions on imaging. Although a variety of liver lesions can show fat on cross-sectional imaging, the presence of fat usually indicates that the lesion is of hepatocellular origin. Less commonly, nonhepatocellular fatty lesions may be distinguished by ancillary clinical and imaging features.

Epithelioid angiomyolipoma of the liver: a case report

Epithelioid angiomyolipoma (EAML) of liver is a rare neoplasm. Hepatic EAML is often misdiagnosed as other neoplasms such as hepatocellular carcinoma due to non-specific clinical and radiologic features. The morphologic features under microscope and immunohistochemistry staining profile are important in the diagnosis EAML. Here, we report a case of 52-year-old man who found 1.2 cm mass in liver by routine checkup. On the impression of hepatocellular carcinoma, lateral sectionectomy of the liver was done. Microscopically, the tumor is composed of predominant epithelioid cells with vascular component and foamy cells. These cells were positive for HMB45, MelanA, and smooth muscle actin and negative for epithelial membrane antigen. The final diagnosis was hepatic EAML.

Clinico-pathological correlation of hepatic angiomyolipoma: a series of 23 resection cases

BACKGROUND

Angiomyolipomas are rare neoplasms of mesenchymal origin and are derived from perivascular epithelioid cells. They usually develop in the kidney and rarely in the liver. Due to their rarity, most hepatic angiomyolipomas have been misinterpreted as hepatocellular carcinoma (HCC) or other hypervascular liver tumours on imaging studies. We aimed to assess the clinico-pathological correlation of hepatic angiomyolipoma.

METHODS

We identified 23 patients with hepatic angiomyolipoma through an institutional database search.

RESULTS

Of 5680 cases of primary liver tumours, 23 (0.4%) had angiomyolipomas (mean age, 43.6 ± 12.4 years; 16 female patients). Hepatitis B virus infection was noted in four patients, whereas a liver mass was incidentally detected on routine health screening in 13 patients. The preoperative diagnoses, before liver biopsy, included HCC in 14, angiomyolipoma in six, focal nodular hyperplasia in two and hepatic adenoma in one patient. Eventually, the preoperative diagnoses were changed to HCC in 12 and hepatic angiomyolipoma in 11 patients. The tumour size was 5.3 ± 4.6 cm, and 22 patients had a single tumour. All tumours exhibited positive findings for human melanoma black-45 and smooth muscle actin staining. During a follow-up period of 52.2 ± 23.7 months, none of the patients exhibited tumour recurrence or mortality.

CONCLUSIONS

Hepatic angiomyolipoma is a rare form of primary liver tumour and is often misdiagnosed as other hypervascular tumours. Although angiomyolipoma is benign in nature, it also has malignant potential; hence, resection is indicated if the tumour grows or malignancy cannot be excluded. Surgical resection is a definitive curative treatment of hepatic angiomyolipoma.

Primary hepatic epithelioid angiomyolipoma: A malignant potential tumor which should be recognized

AIM: To improve the clinical diagnosis and recognition of hepatic epithelioid angiomyolipoma (HEAML).

METHODS: Four cases of primary HEAML were confirmed based on the pathology archive system in our hospital from January 2009 to November 2015. The general state, clinical symptoms, imaging manifestations, histological results and immunohistochemistry of these patients were retrospectively reviewed and analyzed. Studies of HEAML published in the last 15 years were collected from PubMed and MEDLINE to summarize the clinical symptoms, imaging characteristics, pathological features and management of HEAML.

RESULTS: Four cases of primary HEAML were retrieved from our archives. These included three female patients and one male patient, with a mean age of 41.8 ± 11.5 years (ranging from 31 to 56 years). The mean tumor size was 7.3 ± 5.5 cm (ranging from 3.0 to 15 cm). In the contrast-enhanced imaging, the tumor was obviously enhanced in the arterial phase, but enhanced continuously or exhibited a slow-density masse during the venous and delayed phases. Histologically, the tumors mainly consisted of epithelioid cells that comprised approximately 95% of the total neoplastic mass. Although no metastases occurred in our patients, pathological studies revealed necrosis, mitotic figures and liver invasion in two patients, which indicates aggressive behavior. Immunohistochemical staining revealed that human melanoma black 45 (HMB-45) and Melan-A were positive in 4 cases. We only identified 81 cases with primary HEAML, including our present patients, from 26 articles available from PubMed and MEDLINE. The majority of the papers were published as case reports. Only 5 (5/75, 6%) cases were associated with tuberous sclerosis complex (TSC). More than half (35/66) were discovered incidentally upon physical examination. Approximately 65% (22/34) of the patients were misdiagnosed with HCC or other tumors before surgery. Approximately 10% (8/81) of the patients with HEAML had recurrence or metastasis after surgery, which was a very high and alarming rate.

CONCLUSION: HEAML is a very rare primary hepatic tumor that is often misdiagnosed before surgery. Patients should be followed closely after surgery because of its malignant potential.

Hepatic epithelioid angiomyolipoma is a rare and potentially severe but treatable tumor: A report of three cases and review of the literature

Hepatic epithelioid angiomyolipoma (EAML) is a rare type of hepatic tumor. Due to a lack of adequate understanding about this tumor, hepatic EAML is often misdiagnosed as other diseases with similar clinical characteristics such as hepatic cancer. In the present study, 3 cases of hepatic EAML are reported, and the main clinicopathological features of this disease are presented, based on a literature search that included articles published in English between February 2000 and September 2014. A total of 24 hepatic EAML cases were considered, of which, 17 were females and 4 presented multiple liver lesions. Among the patients with single lesions, 2 underwent surgery and relapsed after 5 months and 9 years, respectively. Immunohistochemical staining was positive for human melanoma black-45 in the present 3 cases. The aim of the present study was to focus the attention of clinicians on this type of hepatic tumor in order to improve its diagnosis and treatment.

Visualizing Central Vessels of Hepatic Angiomyolipoma Devoid of Fat Using a 2D Multi-Breath-Hold Susceptibility-Weighted Imaging

Epithelioid hepatic angiomyolipoma (Epi-HAML) is a rare benign mesenchymal tumor with malignant potential. Most of Epi-HAML contains no or only a minimal amount of adipose tissue and poses a diagnostic challenge. Central vessels are characteristic imaging finding of Epi-HAML, which usually were displayed by dynamic contrast imaging. In this paper, we displayed the central vessels of Epi-HAML invisible on conventional MR images using a new developed abdominal susceptibility-weighted imaging (SWI). To the best of our knowledge, this is the first description for the role of SWI in characterization of Epi-HAML.

Gd-EOB-DTPA-enhanced and diffusion-weighted magnetic resonance findings in hepatic epithelioid angiomyolipoma: A case report

The present study reports a case of histologically proven hepatic epithelioid angiomyolipoma that was evaluated with gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging and diffusion-weighted imaging. A 23-year-old female was admitted to the Northern Jiangsu People's Hospital (Yangzhou, Jiangsu, China) due to a 5.6-cm mass in the liver, and a right partial hepatectomy was performed. Magnetic resonance imaging (MRI) revealed a hypointense mass on T1-weighted imaging, and a hyperintense mass on T2-weighted and diffusion-weighted imaging, with a higher apparent diffusion coefficient value compared with normal liver parenchyma. On the dynamic Gd-EOB-DTPA-enhanced MRI scan, the lesion manifested as hypervascular with multiple filiform vessels and a pseudocapsule image, and in the hepatobiliary phase the lesion demonstrated a lack of contrast retention, thus appearing hypointense compared with the background liver. Pre-operatively, EMAL was diagnosed on the basis of these findings in the tumor. The optimum treatment is complete surgical excision and subsequent follow-up. The patient was healthy and free from recurrence at 6 months and 1 year post-surgery. Therefore, knowledge of EAML specific features on dynamic Gd-EOB-DTPA-enhanced and DWI scans may improve the diagnostic accuracy of hypervascular hepatic tumors and may facilitate treatment selection.

Improving recognition of hepatic perivascular epithelioid cell tumor: Case report and literature review

A 58-year-old man presented with the chief complaint of abdominal bloating and was incidentally found to have a liver tumor. As diagnostic imaging studies could not rule out malignancy, the patient underwent partial resection of segment 3 of the liver. The lesion pathologically showed eosinophilic proliferation, in addition to immunohistochemical positivity for human melanoma black 45 and Melan-A, thereby leading to the diagnosis of a hepatic perivascular epithelioid cell tumor (PEComa). A PEComa arising from the liver is relatively rare. Moreover, the name ‘PEComa’ has not yet been widely recognized, and the same disease entity has been called epithelioid angiomyolipoma (EAML), further diminishing the recognition of PEComa. In addition, PEComa imaging findings mimic those of malignant liver tumors, and clinically, this tumor tends to enlarge. Therefore, a PEComa is difficult to diagnose. We conducted a systematic review of PEComa and EAML cases and discuss the results, including findings useful for differentiating perivascular epithelioid cell tumors from malignant liver tumors.

Hepatic angiomyolipomas: ultrasonic characteristics of 25 patients from a single center

Twenty-five pathologically proven hepatic angiomyolipomas (AMLs) were included in the study. Ultrasonic features of hepatic AMLs were reviewed. Three types of echogenicity were observed on ultrasound examination: (i) strong hyper-echogenicity, (ii) moderate hyper-echogenicity and (iii) hypo-echogenicity. Vascular signals within tumors could be detected in 22 (88.00%) tumors as multiple punctiform, filiform or dendriform signals by color Doppler flow imaging. Based on the enhancement patterns in the arterial, portal and late phases, the features of hepatic AMLs on contrast-enhanced ultrasound were divided into four subtypes: (i) "fast in slow out" (68.00%, n = 17); (ii) "fast in same out" (16%, n = 4); (iii) "fast in fast out" (12.00%, n = 3); and (iv) "fast in uneven out" (4.00%, n = 1). Contrast-enhanced ultrasound diagnosed 22 (88.00%) tumors as benign tumors and 13 (52.00%) as hepatic AMLs. Four cases were misdiagnosed as hepatic hemangioma, five cases as focal nodular hyperplasia (total = 36.00%). The rate of correct diagnosis of hepatic AMLs increased significantly from 24.00% for ultrasound alone to 52.00% for contrast-enhanced ultrasound. Therefore, information obtained from ultrasound, color Doppler flow imaging and contrast-enhanced ultrasound should be combined to improve diagnosis.

Hepatic angiomyolipoma mimicking hepatocellular carcinoma: magnetic resonance imaging and clinical pathological characteristics in 9 cases

Hepatic angiomyolipoma (HAML) is a rare mesenchymal tumor of the liver with marked histological diversity. The present study was to review the magnetic resonance imaging (MRI) and clinical pathological features of HAML resembling hepatocellular carcinoma (HCC). Nine patients who underwent surgical resection and had pathological diagnosis of HAML were retrospectively analyzed. All of 9 patients (5 males and 4 females) had a solitary hepatic mass with a median size of 4 cm (from 1.4 cm to 15.3 cm). Seven cases were identified as incidental liver tumors during health screening and 2 patients were diagnosed for hepatic mass when visited hospitals with unspecific abdominal discomfort. Before resection, 6 cases were diagnosed as HCC on MRI. MRI on chemical shift imagings showed a large amount of lipids in 5 cases. The enhancement pattern of MRI was classified into 2 types: in 2 cases, lesions with small or no vessels that demonstrated prolonged enhancement (1 mixed subtype and 1 myomatous subtype) and in 7 cases, lesions with abundant central vessels that show rapid washout (3 mixed subtypes and 4 myomatous subtypes) in the portal venous/delayed phase. All patients underwent resection of hepatic tumor and no recurrence was observed during follow-up (range: 2-24 months) of median 10 months. By immunohistochemistry, the tumor cells demonstrated positive immunostaining for human melanoma black-45, smooth muscle actin, and CD34. In conclusion, all of 9 patients with HAML presented with none or nonspecific clinical manifestations. The diagnosis of HAML relies on disease and immunohistochemistry, but not MRI due to its resemblance to HCC.

Comparison of MRI features for the differentiation of hepatic angiomyolipoma from fat-containing hepatocellular carcinoma

OBJECTIVE

The purpose of this study was to evaluate MRI features for the differentiation of hepatic angiomyolipoma (HAML) from fat-containing hepatocellular carcinoma.

METHODS

We retrospectively reviewed the MRI findings of 20 patients with 22 hepatic angiomyolipomas and 25 patients with fat-containing hepatocellular carcinomas before surgery. The MRI features and apparent diffusion coefficient (ADC) for the two types of tumors were compared and analyzed.

RESULTS

Fat was not detected in nine (40.9%) of the angiomyolipomas. An enhancement pattern of the washout area was seen in eight (36.4%) of the angiomyolipomas and 21 of the hepatocellular carcinomas (84%) (p = 0.001). The sensitivity, specificity, and accuracy of the enhancement pattern for HAML were 63.6% (14/22), 84% (21/25), and 74.5% (35/47), respectively. An early draining vein was seen in 16 (72.7%) angiomyolipomas and two hepatocellular carcinomas (8%) (p < 0.001). The sensitivity, specificity, and accuracy of an early draining vein for detecting HAML was 72.7% (16/22), 92% (23/25), and 83.0% (39/47), respectively. Tumor vessels were noted in 18 (81.8%) angiomyolipomas and six hepatocellular carcinomas (24%) (p < 0.001). The sensitivity, specificity, and accuracy of tumor vessels for HAML were 81.8% (18/22), 76% (19/25), and 78.7% (37/47), respectively. Pseudocapsules were absent in 21 (95.5%) angiomyolipomas as compared with 3 (12%) hepatocellular carcinomas (p < 0.001). The sensitivity, specificity, and accuracy of pseudocapsules for HAML were 95.5% (21/22), 88% (22/25), and 91.5% (43/47), respectively. The ADC of the angiomyolipomas (1.92 ± 0.29 × 10(-3 )mm(2)/s) was significantly higher than that for hepatocellular carcinomas (1.33 ± 0.25 × 10(-3 )mm(2)/s) (p < 0.001).

CONCLUSION

The presence of an early draining vein and tumor vessels, the absence of pseudocapsules and a higher ADC in the hypervascular hepatic tumor on the MRI were helpful for the differentiation of hepatic angiomyolipoma from fat-containing hepatocellular carcinoma.

Hepatic epithelioid angiomyolipoma with arterioportal venous shunting mimicking hepatocellular carcinoma: report of a case

A patient with hepatic epithelioid angiomyolipoma (Epi-AML) with arterioportal venous shunting, who was successfully treated by a laparoscopic left lateral sectionectomy, is presented herein. AML is an uncommon benign neoplasm of the liver. Tumors composed predominantly of epithelioid cells have been subcategorized into Epi-AML, and the treatment strategy for Epi-AML is currently undetermined. There are no reports describing Epi-AML with arterioportal venous shunting to date. An arterioportal venous shunting of the liver tumor was suggested to be one of the malignant signs of the liver tumor. It would be important to differentiate Epi-AML with arterioportal venous shunting from hepatocellular carcinoma and hypervascular metastatic tumors. Minimally invasive resection, such as laparoscopic hepatectomy, for patients having Epi-AML with arterioportal venous shunting may be recommended.

A case of multiple hepatic angiomyolipomas with high (18) F-fluorodeoxyglucose uptake

Background

Hepatic angiomyolipoma is a rare benign mesenchymal tumor. We report an unusual case of a patient with multiple hepatic angiomyolipomas exhibiting high ¹⁸ F-fluorodeoxyglucose (FDG) uptake.

Case presentation

A 29-year-old man with a medical history of tuberous sclerosis was admitted to our hospital for fever, vomiting, and weight loss. Abdominal dynamic computed tomography revealed faint hypervascular hepatic tumors in segments 5 (67 mm) and 6 (10 mm), with rapid washout and clear borders; however, the tumors exhibited no definite fatty density. Abdominal magnetic resonance imaging revealed that the hepatic lesions were slightly hypointense on T1-weighted imaging, slightly hyperintense on T2-weighted imaging, and hyperintense with no apparent fat component on diffusion-weighted imaging. FDG-positron emission tomography (PET) imaging revealed high maximum standardized uptake values (SUVmax) of 6.27 (Segment 5) and 3.22 (Segment 6) in the hepatic tumors. A right hepatic lobectomy was performed, and part of the middle hepatic vein was also excised. Histological examination revealed that these tumors were characterized by the background infiltration of numerous inflammatory cells, including spindle-shaped cells, and a resemblance to an inflammatory pseudotumor. Immunohistochemical evaluation revealed that the tumor stained positively for human melanoma black-45. The tumor was therefore considered an inflammatory pseudotumor-like angiomyolipoma. Although several case reports of hepatic angiomyolipoma have been described or reviewed in the literature, only 3 have exhibited high ¹⁸ F-FDG uptake on PET imaging with SUVmax ranging from 3.3–4.0. In this case, increased ¹⁸ F-FDG uptake is more likely to appear, particularly if the inflammation is predominant.

Conclusion

Although literature regarding the role of ¹⁸ F-FDG-PET in hepatic angiomyolipoma diagnosis is limited and the diagnostic value of ¹⁸ F-FDG-PET has not yet been clearly defined, the possibility that hepatic angiomyolipoma might exhibit high ¹⁸ F-FDG uptake should be considered.

Multi-slice computed tomography manifestations of hepatic epithelioid angiomyolipoma

AIM: To explore the characteristics of multi-slice computed tomography (CT) manifestations of hepatic epithelioid angiomyolipoma (HEA), improve the rate of accurate diagnosis, and reduce the misdiagnostic rate.

METHODS: The multi-slice CT manifestations in five patients who were diagnosed with HEA definitely by postoperative pathological examination were analysed retrospectively. Three female patients and two male patients were included. Before operation, four patients received plain CT scanning and dynamic enhancement scanning, and the other patient only received enhancement scanning, with immunohistochemical analysis conducted after postoperative pathological examination. Four patients were misdiagnosed by CT, including three patients misdiagnosed with hepatic cell carcinoma and one patient with focal nodular hyperplasia.

RESULTS: Upper abdominal multi-slice spiral CT scanning and three-stage enhancement scanning were conducted in five patients with HEA before operation. HEA had certain characteristic CT manifestations: low density masses, a few relatively high-density masses or fat-density masses diffusely shown in foci, clear boundary, round or oval and large focus, and tumour size ranging from 3.1 cm × 2.5 cm to 7.0 cm × 5.2 cm. During enhancement scanning, the foci were significantly enhanced uniformly or non-uniformly during the arterial phase, while during the venous and equilibrium phases, the foci were enhanced continuously or showed obvious low-density masses. Obviously enhanced and widened vessels could be found adjacent to foci or in the central area of foci during the arterial phase.

CONCLUSION: CT manifestations of HEA have certain characteristics. Primary diagnosis can be obtained by combining CT findings with clinical data, but pathological examination is still needed for a definite diagnosis.

Spontaneous rupture of a hepatic epithelioid angiomyolipoma: damage control surgery. A case report

BACKGROUND

Angiomyolipoma (AML) is a rare mesenchymal tumor composed by blood vessels, adipose tissue and smooth muscle cells in variable proportions. Although it is most often diagnosed in the kidney, this tumor may originate from any part of the liver. It is often misdiagnosed as hepatocellular carcinoma (HCC) or other benign liver tumor. We describe a case of spontaneous rupture of hepatic angiomyolipoma in a young woman, with evidence of internal hemorrhage and hemoperitoneum.

CASE REPORT

Liver tumor rupture is a rare but real surgical emergency. In our case it has been managed according to the trauma principles of the damage control surgery. At the time of the observation, the patient presented an instable condition, so the decision-making was oriented toward a less invasive first step of liver packing instead of a more aggressive intervention such as one shot hepatic resection.

CONCLUSION

Damage control surgery with deep parenchymal sutures of the liver and pro-coagulant tissue adhesives packing abbreviates surgical time before the development of critical and irreversible physiological endpoints and permits a more confident second time surgery. This surgical management concept helps to reduce the mortality rate and the incidence of complications not only in traumatic liver damages, it works very well in spontaneous liver ruptures as well.

Differentiating hepatocellular carcinoma from angiomyolipoma of the liver with CT spectral imaging: a preliminary study

AIM

To investigate the value of computed tomography (CT) spectral imaging in differentiating hepatocellular carcinoma (HCC) from angiomyolipoma (AML) during the arterial phase (AP) and portal venous phase (PP).

MATERIALS AND METHOD

Fifty-three patients underwent spectral CT during the AP and PP. Forty-five patients had 45 HCC and eight patients had eight AML. Iodine concentrations in the lesions were normalized to those of the aorta. The normalized iodine concentrations (NIC) and the lesion-normal parenchyma iodine concentration ratio (LNR) were calculated. The two-sample t-test was performed to compare quantitative parameters. Two readers qualitatively assessed lesion types on the basis of imaging features. Sensitivity and specificity were compared between the qualitative and quantitative studies.

RESULTS

NICs and LNRs in patients with HCC differed significantly from those in patients with AML: mean NICs were 0.25 ± 0.06 mg/ml versus 0.59 ± 0.03 mg/ml, respectively, during the AP and 0.52 ± 0.12 mg/ml versus 0.78 ± 0.03 mg/ml, respectively, during the PP. Mean LNRs were 2.97 ± 0.42 versus 5.85 ± 0.43, respectively, during the AP and 0.99 ± 0.17 versus 1.36 ± 0.05, respectively, during the PP. The NICs and LNRs for HCC were lower than those of AML during the AP and PP. The differences were significant (p < 0.05). The threshold NIC and LNR had high sensitivity and specificity in differentiating HCC from AML.

CONCLUSION

CT spectral imaging with the quantitative analysis of iodine concentration may help increase the accuracy of differentiating HCC from AML.