Orbital liposarcoma
Introduction
Introduction to orbital liposarcoma Liposarcoma (liposarcoma) is a malignant representative of fatty tumors. It is composed of immature fat cells. It is a malignant mass of lipoblasts. It is a common soft tissue sarcoma in adults. It is the site of fat accumulation in the body, such as the abdomen and retroperitoneum. There are many parts such as hips and hips, which are rare in the eyelids. Orbital liposarcoma is a malignant representative of fatty tumors. It is composed of immature fat cells and is a malignant mass of lipoblasts. It acts as a primary lesion or as a lesion that metastasizes from a distant primary location. In the eyelids. The main clinical manifestations are painful or painless eyeballs that progress faster, and the margins that touch the border and have a slightly harder texture, swelling of the eyelids, limited eye movement, etc. may also have vision loss and diplopia. basic knowledge The proportion of illness: the incidence rate is about 0.05% - 0.07% Susceptible people: no special people Mode of infection: non-infectious Complications: eyeballs, eye movement disorders, exposed keratitis
Cause
Causes of orbital liposarcoma
(1) Causes of the disease
Orbital liposarcoma appears to be an originated from primitive stromal cells rather than mature adipocytes, possibly derived from a cell in the orbital fascia undergoing lipoblastic differentiation. The stimuli for this mutation are unknown, and the trauma may be Predisposing factors.
(two) pathogenesis
Not very clear.
Prevention
Orbital liposarcoma prevention
(1) Minimize infection and avoid exposure to radiation and other toxic substances, especially drugs that inhibit immune function; active virus and certain physical properties (such as radiation), chemical (such as anti-epileptic drugs, adrenal gland) The long-term application of corticosteroids may lead to abnormal proliferation of lymphoid tissue, which ultimately leads to lymphoma. Therefore, pay attention to personal and environmental hygiene, avoid drug abuse, and pay attention to personal protection when working in a harmful environment.
(2) Appropriate exercise, enhance physical fitness, and improve their disease resistance.
Complication
Orbital liposarcoma complications Complications, eyeballs, ocular dyskinesia, exposed keratitis
Exposure keratitis caused by eyeball protrusion and eye movement disorder and destruction of bone wall compression.
Symptom
Orbital liposarcoma symptoms Common symptoms Radial venous reflux disorder Visual impairment Optic nerve atrophy Eyeballs can not be free to move edema eyeballs
Fat sarcoma is more common in adults, occasionally in adolescents. The main clinical manifestations are unilateral ocular protrusion, which develops rapidly. Different symptoms can occur according to the primary site. The early stage of the tumor at the tip of the iliac crest oppresses the optic nerve, causing vision loss, fundus examination. Visible optic disc edema or atrophy, rapid tumor growth can cause eye movement disorders, axial axonal or accompanied by displacement, the tumor originating in the anterior temporal region, can reach the mass around the periorbital, soft, smooth and movable.
The imaging of orbital liposarcoma has certain characteristics. The B-mode ultrasound examination has clear boundary and strong internal echo. Because the tumor grows rapidly and has necrotic cavity, the echo appears to have a sound-transparent cavity on the basis of strong echo. Thus, a strong reflected light group inside the lesion appears, and CDI can show color blood flow. Due to the necrotic cavity in the tumor and the presence of fibrovascular tissue, the density of the CT image shows uneven density, and the adipose tissue shows a negative CT value. The fibrous vascular tissue, the liquefied cavity can be shown as positive CT value, and bone destruction can be seen. MRI imaging has high signal area in T1WI and T2WI.
Examine
Examination of orbital liposarcoma
Pathological examination: As seen by the naked eye, liposarcoma has a mottled and diverse appearance on the cut surface due to the mixing of lipid and mucoid tissue. It often has bleeding and necrotic areas. The tumor has a sticky and slippery appearance. Under the microscope, the fat sarcoma For well-differentiated, mucin-like, round cells and polymorphisms, well-differentiated and mucoid-like types appear to have a better prognosis. Most orbital liposarcomas are mucin-like and are called mucin-like liposarcoma, mucin-like Liposarcoma contains a fairly well-differentiated spindle shape, and the star or round lipoblasts are suspended in mucus or a mucopolysaccharide matrix. Usually the tumor is filled with plexiform blood vessels, which helps to make it with true mucinous tumors (very few blood vessels) In distinction, in some cases, tumors may have more malignant features and show rhabdomyoblast differentiation, which is sometimes referred to as mesenchymomas.
In terms of etiology, orbital liposarcoma appears to be an originated from primitive stromal cells rather than mature adipocytes, possibly derived from a cell in the orbital fascia undergoing lipoblastic differentiation. The stimuli for this variant are unknown.
1. X-ray examination: the plain film can be free of abnormal performance, or only the density of the sputum area is increased, and a small number of bone wall bones can be thinned or destroyed.
2. B-ultrasound: B-ultrasound appears as a solid lesion with irregular shape. The general boundary is clear, the internal echo is strong and uneven, and there is no compressibility.
3. CT scan: the lesions are mostly located outside the muscle cone, the shape is irregular, cystic or multi-cavity, the boundary is still clear, different proportions of fat components can be seen in the mass and the negative value is low density, which is the characteristic of the disease. The typical signs are positive and negative mixed density shadows, where positive CT values represent soft tissue components such as blood vessels and fibers, which have different degrees of enhancement, negative values represent fat components, no enhancement, and sometimes a small proportion of fat. CT thin-layer examination is particularly important. Large tumors can invade the muscle cone, or even the entire eyelid, compress or surround the extraocular muscles and/or optic nerve. The tumor can invade the adjacent wall and cause worm-like bone destruction.
4. MRI: The tumor showed high and low-hybrid signals on T1WI, and the high signal was inhibited by the fat-suppressing sequence and showed a low signal, suggesting that it is a fat component. It is a characteristic feature of the disease, and the tumor is moderately signaled on T2WI. Different degrees of enhancement, in which the strengthening area is prompted by blood vessels, fibers and other components, the shape of the tumor is irregular, the boundary is clear, and the enhanced scanning combined with fat suppression technology can clearly show the relationship between the lesion and the extraocular muscle and optic nerve, and can also accurately display the tumor invasion. range.
Diagnosis
Diagnosis and differentiation of orbital liposarcoma
diagnosis
According to the clinical history, eye signs and imaging findings, a preliminary clinical diagnosis can be made, and the exact diagnosis depends on histopathological examination.
X-ray plain film has little value in the diagnosis of this disease. B-ultrasound can show lesions, but it is difficult to show the lesions in the proximal apical region. It is also difficult to accurately show the relationship between lesions and adjacent structures. The diagnosis value of this disease is limited. CT is the disease. The diagnostic specificity is good, but the sensitivity is poor. It is difficult to display the small fat foci in the lesion. It is also difficult to accurately show the relationship between the lesion and the adjacent structure. MRI has the best sensitivity to the disease, and can clearly and accurately show the extent and proximity of the lesion. The structural relationship provides reliable information before surgery, and the combined use of CT and MRI can improve the accuracy of the diagnosis of this disease.
Differential diagnosis
1 Dermoid cyst: fat-like density or signal can also be seen in the lesion, but it is usually expressed as a round, oval or semi-circular mass outside the upper quadrant of the eyelid. The boundary is clear and sharp, and the adjacent wall is compressed and thinned. Even the lesion protrudes into the armpit;
2 lipoma: a long history, clinical manifestations of painless eyeballs, CT, MRI more than a round lumps, density or signal and fat, clear boundaries, generally do not invade the iliac bone.
