Magnetic Resonance Imaging of Adrenal Angiomyolipoma

Adrenal Angiomyolipoma: A Case Report

Angiomyolipoma (AML) is a mesenchymal tumor that arises from perivascular epithelioid cells most commonly seen in the kidney and rarely in extrarenal sites. Adrenal AML is a rare clinical entity with only 16 cases reported in the literature according to the World Health Organization report in 2017. We present a 68-year-old male evaluated in our emergency room with worsening chronic right upper quadrant abdominal pain. Computerize tomography (CT) revealed a large right adrenal mass. Adrenelectomy was performed, and the histopathology report confirmed the diagnosis and the tumor size was the largest ever reported. Patient was discharged uneventfully.

Lipomatous tumors of adrenal gland: A case series of 5 patients and review of the literature

INTRODUCTION

Lipomatous tumors of the adrenal glands are a diverse group of tumors characterized by the composition of adipose tissue. This group of tumors include myelolipomas, angiomyolipomas (AML), lipomas, and teratomas. They are usually benign, non-functioning tumors, and they account for 5% of all primary adrenal tumors. This study aimed to elucidate the management of the initial size of the adrenal mass and symptoms of presentation. We provide a succinct literature review regarding angiomyolipomas tumors of the adrenal glands.

PRESENTATION OF CASES

Here, we report 5 cases of lipomatous tumors of the adrenal glands. All 5 tumors were non-functioning. Four of them were myelolipoma, and one was AML. Two cases of myelolipoma presented with flank pain, while the rest of the 3 cases presented with hypochondrium pain. Three cases of myelolipoma were managed with laparoscopic adrenalectomy, one case of myelolipoma was converted from laparoscopic to open adrenalectomy because of abdominal adhesions, and the last case was AML and was managed with open adrenalectomy. All patients had an uneventful recovery with regular follow-up.

DISCUSSION

Myelolipoma, the most common lipomatous tumor of the adrenal gland, consists of a mixture of bone morrow element and adipose tissue. AML consists of a mixture of a thick-walled blood vessel, smooth muscle, and adipose tissue. They mimic many different benign and malignant tumors on radiography, and the histopathological examination is still needed to confirm the diagnosis. There is still controversy in the management of these tumors. Usually, the management is individualized on each case. Reporting of these tumors are increasing due the wide-spread use of modern imaging modalities.

CONCLUSION

Adrenal lipomatous tumors are uncommon but with the increase use of imaging modalities their detection has increased. Further studies are needed to establish guidelines in the management of these tumors, especially that they can mimic malignant conditions.

Spontaneous haemorrhage of an adrenal angiomyolipoma: case report

Background

Angiomyolipomas are rare mesenchymal tumours arising from the perivascular epithelioid cells consisting of variable amounts of adipose, thick-walled blood vessels and smooth muscle cells. These benign tumours commonly occur in the kidney with only a few case reports of adrenal angiomyolipomas which have the potential to reach a large size and haemorrhage.

Case presentation

A 45-year-old lady presented with a 3-week history of right loin pain, nausea and vomiting. A CT scan revealed a right adrenal angiomyolipoma measuring 6.3 × 6.8 cm with associated haemorrhage. The lesion was successfully treated with right open adrenalectomy, and histology confirmed the diagnosis of adrenal angiomyolipoma. The patient remained well with no evidence of recurrence at the 36-month follow-up.

Conclusion

Adrenal angiomyolipomas are rare benign tumours that have the ability to reach a large size and potential to bleed. Here, we report the second case of spontaneous haemorrhage in an adrenal angiomyolipoma, which was successfully treated with open adrenalectomy.

Angiomyolipoma of the Adrenal Gland: A Report of Two Cases and Review of the Literature

BACKGROUND Angiomyolipoma is a benign tumor composed of blood vessels, smooth muscle cells, and adipose tissue and has been described as belonging to the group of tumors of perivascular epithelioid cell origin (PEComa), commonly found in the kidneys and strongly associated with tuberous sclerosis. Only a few cases of extra-renal angiomyolipoma have previously been reported in the literature, most commonly in the liver. Adrenal angiomyolipoma is very rare, is usually asymptomatic, and is often found incidentally, with only 14 previously reported cases identified in the literature. CASE REPORT We report two cases of adrenal angiomyolipoma that were identified by abdominal computed tomography (CT). The first case presented in a 36-year-old man and was an oval-shaped adrenal mass, measuring 5.2×4.2×3.1 cm. The second case presented in a 61-year-old woman and was a round-shaped mass measuring 8.6×9.5×8.1 cm. Both patients underwent adrenalectomy. Histopathology and immunohistochemistry confirmed the diagnosis of benign angiomyolipoma composed of adipose tissues, blood vessels, and smooth muscle cells. CONCLUSIONS We present two rare cases of adrenal angiomyolipoma. We have reviewed the literature and identified 14 other cases of adrenal angiomyolipoma, and discuss the clinical, radiological, and pathological features of this rare tumor.

Angiomyolipoma of the Adrenal Gland: A Case Presentation and a Review of Adrenal Lipomatous Tumors

Angiomyolipoma (AML) is a typically benign renal tumor derived from mesenchymal tissue. Extrarenal occurrences of AML are possible, but the adrenals are an exceedingly rare site. To date, a total of 4 cases of adrenal AML have been documented in the English literature.1-3 We present a case of right-sided adrenal AML found in a patient who initially presented with right-sided flank pain. Differential diagnosis of adrenal masses should include lipomatous tumors, as operative considerations and prognoses can be drastically altered.

Lipomatous tumours in adrenal gland: WHO updates and clinical implications

Adrenal lipomatous tumour is a group of adrenal tumours with a significant component of adipose tissue. According to the current World Health Organization (WHO) classification of tumours of endocrine organs, adrenal myelolipoma is the only entity amongst the group of tumours being described. In the literature, other more recently documented adrenal lipomatous tumours included 24 lipomas, 32 teratomas and 16 angiomyolipomas. Rare fatty tumours of the adrenal gland comprised liposarcoma, hibernoma, adrenocortical tumours with fat component and rare adrenal tumours with fat component. Myelolipoma comprises approximately 3% of primary adrenal tumour. It is noted more commonly in females and in the right adrenal gland. Approximately 40 bilateral myelolipomas were reported. The tumour is most frequently recorded in patients between fifth and seventh decades of life. Adrenal lipomas are often seen in males and in the right adrenal gland. They were commonly noted in patients in the sixth decade of life. The diagnosis could only be possible on examination of the surgically removed specimen. Adrenal teratomas were more common in females and with a bimodal age distribution. Slightly over 60% of the patients with adrenal teratoma are symptomatic. Adrenal angiomyolipomas were often symptomatic, more common in females and in the fifth decades of life. To conclude, adrenal lipomatous tumour is uncommon. They are often benign and non-functional. It is important to recognize the features of this group of lipomatous tumours in the adrenal gland as they are being detected on increasing incidence as a result of the wide-spread use of modern imaging modalities.

Hepatic angiomyolipoma: differential diagnosis from other liver tumors in a special reference to vascular imaging - importance of early drainage vein

A 51-year-old female had been diagnosed with a hemangioma in the hepatic segment 6 (S6). After a 6-year follow-up, enlargement of the tumor was detected. The tumor was clearly enhanced in the arterial phase, and the enhancement remained in the portal phase on computed tomography (CT). Although the primary differential diagnosis on CT was hepatocellular carcinoma (HCC), we worried about the possibility of other vessel system tumors because the tumor remained to be enhanced at the portal phase for HCC and all tumor markers of HCC were negative. We performed angiography to determine the tumor nature and to seek other tumors. Angiography showed tumor stain at the hepatic S6 with an early obvious drainage vein from the tumor flowing through the right hepatic vein into the inferior vena cava. In addition to tumor stain and the drainage vein, there were many small poolings of contrast medium in the whole liver, which were suspected as dilatation of the hepatic peripheral artery. We suspected the tumor as a benign tumor such as hepatocellular adenoma or focal nodular hyperplasia, but the possibility of HCC could not be ruled out. Hepatic posterior sectionectomy was done to completely remove the drainage vein with the tumor. Intraoperative histological examination revealed the tumor as not malignant and not HCC. Later, immunohistochemical analysis uncovered that the tumor had high expression of HMB-45 and, therefore, the final diagnosis was angiomyolipoma. We think that detecting an early drainage vein from the tumor would be a key point for diagnosing hepatic angiomyolipoma.

Unilateral giant renal angiomyolipoma and pulmonary lymphangioleiomyomatosis

Angiomyolipomas (AMLs) are mesenchymal neoplasms, named so because of the complex tissue composition represented by variable proportions of mature adipose tissue, smooth muscle cells, and dysmorphic blood vessels. Although AMLs may rise in different sites of the body, they are mostly observed in the kidney and liver. In the case of renal AMLs, they are described in two types: isolated AMLs and AMLs associated with tuberous sclerosis (TS). While most cases of AMLs are found incidentally during imaging examinations and are asymptomatic, others may reach huge proportions causing symptoms. Pulmonary lymphangioleiomyomatosis (LAM) is a rare benign disease characterized by cystic changes in the pulmonary parenchyma and smooth muscle proliferation, leading to a mixed picture of interstitial and obstructive disease. AML and LAM constitute major features of tuberous sclerosis complex (TSC), a multisystem autosomal dominant tumor-suppressor gene complex diagnosis. The authors report the case of a young female patient who presented a huge abdominal tumor, which at computed tomography (CT) show a fat predominance. The tumor displaced the right kidney and remaining abdominal viscera to the left. Chest CT also disclosed pulmonary lesions compatible with lymphangioleiomyomatosis. Because of sudden abdominal pain accompanied by a fall in the hemoglobin level, the patient underwent an urgent laparotomy. The excised tumor was shown to be a giant renal AML with signs of bleeding in its interior. The authors call attention to the diagnosis of AML and the huge proportions that the tumor can reach, as well as for ruling out the TSC diagnosis, once it may impose genetic counseling implications..

Clinicopathological analysis of 156 patients with angiomyolipoma originating from different organs

Angiomyolipoma (AML) is a benign mesenchymal tumor composed of variable proportions of adipose tissue, spindle and epithelioid smooth muscle cells and abnormal thick-walled blood vessels. Approximately one-third of epithelioid AML (EAML) cases have been reported to have metastasis. Thus, it would be of interest to identify the adverse pathological parameters correlated with outcome. However, few studies have been conducted on large numbers of samples. The aim of this study was to highlight the clinicopathological features of AML and the morphological features of EAML, which were correlated with malignant behaviors in patients from a single institutional series analysis. One hundred and fifty-six consecutive AMLs, correlating with pathological characteristics, were analyzed between 1981 and 2010. The Chi-square test was performed to clarify the significance of the clinicopathological factors among the regular and epithelioid subtypes with or without atypia. The two organs most commonly involved were the kidney (77%, 120/156) and liver (14%, 22/156). Of the 156 AMLs, EAMLs (17.3%, 27/156) had more marked mitosis, hemorrhage and multinucleated giant cells compared with the regular AMLs (82.7%, 129/156). The 11 EAMLs with atypia (40.7%, 11/27) had more nucleoli and mitotic cells compared with the 16 EAMLs without atypia (59.3%, 16/27; p<0.05). Follow-up results of 79% of cases (124/156) were obtained, and of these, only one kidney AML (0.8%, 1/124) presented with liver metastasis one year after nephrectomy. This sizeable single institutional AML series analysis revealed that the kidney and liver were the two most commonly involved organs, and most of the cases presented a benign clinical course. Few EAMLs were malignant, although adverse features including atypical mitotic figures, blood vessel invasion and tumor embolus may be significant in predicting malignant behavior.

Myelolipomas and other fatty tumours of the adrenals

Background

Lipomatous tumours of the adrenals are almost always benign. The importance of recognising their characteristic radiological features, leading to their correct treatment, is fundamental, as there has been an increase in the identification of these lesions. Our goal was to review all lipomatous tumours of the adrenal glands, particularly myelolipomas, their imaging methods and surgical management, updated in 2011.

Methods

This was a retrospective review of articles published in the USA and Europe, from 1979 to date. The sites from which information was retrieved covered PubMed, Medscape, Clinical Imaging, Histopathology, Urologia Internationalis, Archives of Surgery, JACS, the American Urological Association, BMJ, Medline, and Springer Link. We report areas of controversies in addition to well established guidelines.

Results

We reviewed 45 articles, that confirmed, with a high level of evidence-based medicine, that the diagnosis of a lipomatous adrenal tumour is made by various imaging procedures, particularly computed tomography (CT). We emphasise the importance to their management of the initial size of the adrenal mass, its increase in size over time, in addition to the presence of symptoms.

Conclusion

Lipomatous tumours of the adrenals are most frequently benign. The diagnosis is usually made by various techniques, in particular CT. The fundamental characteristics indicating the necessity of surgical intervention are the symptoms presented, volume of the tumoral mass (>5 cm), and the increase in size of the tumour as shown in two consecutive imaging studies.

Adrenal tumors with late enhancement on CT and MRI

OBJECTIVES

To identify adrenal masses showing gradual persistent enhancement on delayed contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI).

MATERIALS AND METHODS

Computed tomography or magnetic resonance images of pathologically proven 400 adrenal tumors were retrospectively reviewed over a 10-year period. We included only adrenal tumors showing gradual persistent enhancement on CT and MRI performed at 15 and 5 min, respectively, after contrast material injection.

RESULTS

Four tumors in four patients (three men and one woman; mean age, 51 years) met the inclusion criteria. These lesions were as follows: two ganglioneuromas, one myelolipoma with infarction, and one angiomyolipoma with minimal fat. All of these tumors showed gradual persistent enhancement, and highest attenuation during delayed contrast-enhanced CT or strongest enhancement during delayed contrast-enhanced MRI.

CONCLUSION

The differential diagnosis of adrenal tumors showing gradual persistent enhancement on delayed contrast-enhanced CT and MRI should include ganglioneuroma, myelolipoma with infarction, and angiomyolipoma with minimal fat.

Lipomatous tumors of the adrenals--a report on 18 cases and review of the literature

The lipomatous tumors of the adrenals are hormonally inactive lesions, often of a benign nature, such as myelolipomas, lipomas, angiomyolipomas, or mature teratomas, and are rarely malignant, such as liposarcomas. The importance of recognizing their characteristic radiological images, which would lead to their correct treatment, is fundamental since there has been an increase in the demonstration of this lesion, often detected incidentally. The various imaging procedures, although not allowing to formulate a histological diagnosis, nonetheless permit to determine the volume of the tumoral mass and their evolution. These two factors are of significant importance in the planning of the correct surgical procedure, while a third important factor is the proper evaluation of the symptoms presented by the patient. Regarding the treatment, on the basis of our own experience, which agrees with that of other authors, the surgical removal of any lesion greater than 5 cm is mandatory.

Neoplasms of the Perivascular Epithelioid Cell Involving the Abdomen and the Pelvis

Neoplasms of the perivascular epithelioid cell (PEComas) represent a recently described heterogeneous group of mesenchymal tumors characterized by the presence of specific histological, immunohistochemical, and ultrastructural findings. The PEComas encompass a family of neoplasms that include angiomyolipomas, clear cell sugar tumors, and lymphangioleiomyomatosis. The PEComas demonstrate a wide spectrum of clinicobiological behavior and imaging findings. Perivascular epithelioid cell, as the name implies, is a unique cell that is characterized by perivascular distribution and epithelioid morphology. Perivascular epithelioid cell consistently shows immunoreactivity to melanocytic and smooth muscle markers including HMB-45 and actin. Abdominopelvic PEComas are found at a variety of somatic and visceral locations including kidney, liver, pancreas, gastrointestinal tract, genitourinary tract, peritoneum, and retroperitoneum. A subset of patients with abdominopelvic PEComas manifests tuberous sclerosis complex. In this paper, we review the histological spectrum and discuss the imaging findings of the PEComas that involve the abdomen and pelvis.