Myelolipoma of the liver

Primary hepatic myelolipoma: A case report and review of the literature

BACKGROUND

Primary hepatic myelolipoma is a rare hepatic mesenchymal tumor mixed by adipose tissue and bone marrow, and there is a lack of general guidelines related to its epidemiology and clinical management.

CASE SUMMARY

A 26-year-old woman was admitted to our department complaining of a newly found tumor on her left lobe of the liver. The tumor was painless and not associated with any systemic or localized compressive symptoms. Serological tests disclosed a slight increase of gamma-glutamyl transpeptidase (70.0 U/L) and total bilirubin (19.2 μmol/L). Ultrasonography showed a mass about 5.0 cm × 5.0 cm in size that was located in the left lobe of the liver and displayed hyperechoic and well-encapsulated characteristics. Surgical resection was applied, and the following histopathological examination observed a variable proportion of myeloid tissues scattering throughout mature fibrotic adipose tissues, in which myeloid, erythroid, and megakaryocytic cells can be found in magnified view. The follow-up did not show any changes 6 mo after surgery.

CONCLUSION

This case highlights an extremely rare hepatic mesenchymal tumor, the primary hepatic myelolipoma, and discloses the common characteristics behind this disease and gives clinical recommendations.

MR imaging to detect myelolipomas of the liver: A case report and literature review

RATIONALE

Primary hepatic myelolipoma is a rare benign neoplasm comprising mature adipose tissue and marrow components in various proportions. Chemical shift imaging (CSI) can distinguish the lipid within the tumor clearly; however, there have been no reports on the CSI of hepatic myelolipoma.

PATIENT CONCERN

A 20-year-old woman visited our hospital after discovering a space-occupying lesion in the liver with a history of more than 1 year. She felt distension pain and discomfort under the xiphoid process, accompanied by nausea, vomiting, and occasional chest oppression.

DIAGNOSIS

The tumor showed a well-defined mass with a pseudocapsule and a heterogeneous appearance on both T1- and T2-weighted magnetic resonance (MR) images. CSI analysis showed a signal decline within the tumor. Based on the histopathology, the tumor was diagnosed as hepatic myelolipoma.

INTERVENTIONS AND OUTCOMES

The patient underwent a right hepatectomy, and the postoperative vital signs were stable. Two weeks later, the patient was discharged safely.

LESSONS

Although hepatic myelolipoma is extremely rare, this condition should be considered in differential diagnosis when CSI shows that hepatic lesions contain fatty.

Synchronous occurrence of a hepatic myelolipoma and two hepatocellular carcinomas

Myelolipoma is a rare tumor composed of fat and bone marrow components, most of which are located in the adrenal gland. Myelolipoma in the liver is extremely rare. To date, only 10 cases have been reported in the English-language medical literature. In one of these cases, the hepatic myelolipoma was found within a hepatocellular carcinoma (HCC). In the present study, we report the first case of the synchronous occurrence of hepatic myelolipoma and HCCs in different liver sections of one patient, a 26-year-old female who was admitted to our hospital because of a 4-d history of upper abdominal pain. The unenhanced computed tomography (CT) images showed a well-defined low-density mass with adipose components in the right liver lobe, 4.2 cm × 4.1 cm in size. Two inhomogeneous low-density masses were found in the left liver lobe, 8.6 cm × 7.7 cm and 2.6 cm × 2.6 cm in size. The masses in both the right and left liver lobes were heterogeneously enhanced in the contrast-enhanced CT images. Based on the results of the imaging examination, the mass in the right liver lobe was preliminarily considered to be a hamartoma, and the two masses in the left liver were preliminarily considered to be HCCs. We performed a right hepatectomy, a left hepatic lobectomy, and a cholecystectomy. Microscopic and immunohistochemical results revealed that the tumor in the right liver lobe was a hepatic myelolipoma, and that the two tumors in the left liver lobe were HCCs.

Myelolipoma of the Liver

A 49-year-old woman presented with a 2-year history of back pain. An abdominal computed tomography revealed a 15.0 × 12.0 cm hypodense lesion in the posterior right lobe of her liver. A right hepatic lobectomy was performed, which revealed a well-demarcated lipomatous tumor that microscopically proved to be a myelolipoma. Our case together with 10 other well-documented cases showed the median age of the patients as 55 years (range, 40-69), a predilection for the female gender, and the right lobe of the liver as the most commonly involved site.

Giant Myelolipoma in the Spleen: A Rare Case Report and Literature Review

Myelolipomas are benign tumors, consisting of hematopoietic cells and mature adipose tissue, which mainly occur within the adrenal gland. Extra-adrenal myelolipomas are rare, and fewer than 60 cases have been reported in the literature. Here, we report a case of intrasplenic myelolipoma in a 42-year-old man with more than 1 month of abdominal pain. Computed tomography scanning revealed a giant, heterogeneous, well-demarcated mass in the spleen. Splenectomy was performed, and an intrasplenic giant mass was completely excised. The diagnosis of myelolipoma was made based on morphological examination. To the best of our knowledge, this is the third reported case of myelolipoma in the human spleen.

Angiomyolipoma mimicking true lipoma of the liver: report of two cases

Hepatic angiomyolipoma (AML) is very rare and only about 80 cases have been reported. The tumor is fundamentally heterogeneously composed of the three tissue components of blood vessels, smooth muscle cells (SMC), and fat cells. Two cases of hepatic AML are reported here, both of which are histologically composed predominantly of a fat cell element and resembled true lipoma (lipomatous AML). However, careful examination of both tumors revealed the presence of a small amount of epithelioid SMC, especially around blood vessels. Immunohistochemical study using monoclonal antibody for melanoma (HMB-45) clearly revealed a small amount of HMB-45-positive SMC around the blood vessels and scattered in the diffuse fat cell growth in both tumors. Since no liver tissue components or primary liver tumors are reactive with HMB-45 except AML cells, the presence of HMB-45-positive cells within the tumor clearly established the diagnosis of hepatic AML. Any fatty tumor or focal fatty lesion of the liver that superficially resemble true lipomas should be tested for the presence of HMB-45-positive SMC in the tumor to differentiate it from AML.

Case report: lipoma of the liver--ultrasound, CT and MR imaging

A case of lipoma of the liver is presented; ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI) findings are reviewed and compared with previous reports. The ultrasound pattern and appearance of the tumour in CT as well as MRI are discussed.

Myelolipoma of the liver. A case report

We treated a 56 year-old woman with myelolipoma originating from the liver. Hepatic imagings, including ultrasound and computed tomography (CT), demonstrated characteristic features of a fat-enriched tumor. Since this tumor was symptomatic, hepatic resection was done, with good results. The histology revealed tissues mainly composed of fat and bone marrow elements. The diagnosis was hepatic myelolipoma.