【Philips daily case】【Misdiagnosis analysis】Hepatic angiomyolipoma is misdiagnosed as a case of liver cancer

Patient, female, 50 years old, farmer

Due to the pain in the right upper quadrant for more than 1 month, the B ultrasound in the outer hospital was diagnosed with liver cancer and admitted to our hospital for treatment

Physical examination: clear consciousness, positive body shape, no yellow staining of the skin and sclera; No abnormalities on cardiopulmonary auscultation; Soft abdomen, hepatosplenomegaly subcostal, negative signs of ascites, no edema

Auxiliary examination after admission: normal alpha-fetoprotein, normal liver function, normal blood count, 1 to 3 pustules in the stool, negative HBV and HCV-related etiology

Ct scan showed that the right lobe of the liver was 6.

Figure 1 CT sweep

Initial diagnosis: primary liver cancer

The tumor and part of the liver lobectomy were removed

Microscopic examination (Figure 2): Tumor cells are diffuse, epithelial-like, nucleus morphologically irregular, cytoplasmic eosinophilic or transparent, and multinucleated giant cells

Immunohistochemical staining: As shown in Figures 3~9: CD34 endothelial cells (-), tumor cells CK8/18(-), residual hepatocytes can be seen in the figures are positive; Tumor cells Hepat (-), positive for residual hepatocytes; Tumor cells HMB45 (+) while residual hepatocytes are negative; The proportion of tumor cells Ki67-positive cells <2%; Tumor cells Melan-A(+), SMA(+

Figure 2 HE staining

Figure 3 IHD CD34(-)

Figure Immunohistochemical staining results

Final diagnosis: Hepatic epithelial-like angiomyolipoma (AML), patients recover well after surgery and follow-up for one year without recurrence

discuss

Hepatic AML is a member of the perivascular Epithelioid Cell Tumor (PEComa) family, the etiology and pathogenesis are unclear, is first reported by Ishak in 1976

CT imaging of liver AML varies greatly, depending on the content of fat in the tumor and the proportion of abnormal blood vessels, and in typical cases, the CT value is often negative when there is fat shadow in the tumor

Tsui et al.

In terms of immunohistochemistry, smooth muscle components express leiomy actin (SMA), while epithelial-like components express HMB45 (monoclonal antibody to melanoma) and Melan A, but the epithelial labels PCK and EMA are negative

Differential diagnosis: In this case, the above-epithelial-like cell components are dominant, so it is necessary to distinguish it from

(1) Hepatocellular carcinoma

(2) Hepatoblastoma
.
Antibodies to individual hepatometoma human melanoma HMB45 (+), but hepatoblastoma cells resemble blastocytes, with bone and cartilage components visible inside, and this tumor is more likely to occur in infants and young children
.

(3) Epithelial-like leiomyosarcoma
.
Tumor cells tend to be hypermorphic, and nuclear division is visible or common
.

Treatment: The treatment of liver AML is generally surgical resection, and it is also advocated that if the diagnosis can be confirmed, it can be followed up for observation and not removed
for the time being.
When liver AML with a high fat content is removed, if the tumor is squeezed, fat embolism may occur, which is life-threatening
.
The vast majority of clinical reports have no recurrence after surgery, but Deng et al.
have recently reported a case of lesion malignancy, metastasis, and eventual death, suggesting that if the liver AML is large, rapid growth, polymorphic nucleus, and P53 positive, it is necessary to be vigilant against malignancy
.

Comments:

At present, common clinical examination methods for diagnosing liver cancer include the detection of alpha-fetoprotein in the blood, fucoidase, imaging tests, etc
.
The sensitivity of alpha-fetoprotein and fucoidase in the blood is only about 80%, and the negative of these two indicators cannot exclude liver cancer, and positive cannot confirm liver cancer
.
Tests such as ultrasound, CT, or MRI scans may also be misdiagnosed
because sometimes the imaging of cirrhotic nodules and liver AML is similar to that of liver cancer.
Pet tests can also be used when in doubt to identify benign or malignant tumors
.
However, it is difficult to implement
due to high prices or limited conditions.

Ct imaging of liver AML varies greatly, mainly depending on the content of fat in the tumor and the proportion of abnormal blood vessels, in typical cases, when there is fat shadow in the tumor, the CT value is often negative, and it is not difficult to
diagnose liver AML.
However, some liver AML has no characteristic manifestations due to lack of fat in imaging, and it is easy to misdiagnose
.
For example, the tumor in this case lacks typical fat and smooth muscle components, the morphology is relatively single, and the imaging lacks typical angiomyolipoma characteristics, thus misdiagnosing it as liver cancer, which is worthy of the attention
of clinical, imaging and pathologists.