lacrimal gland pleomorphic adenoma
Introduction
Introduction to lacrimal gland pleomorphic adenoma Pleural gland pleomorphic adenoma (pleomorphicadenomaofthelacrimalgland), also known as lacrimal adenocarcinoma, is the most common lacrimal gland epithelial tumor, accounting for about 50%. It is a benign tumor composed of epithelial and interstitial components. It used to be called benign mixed tumor. Adulthood is good, single eye disease. basic knowledge The proportion of illness: the incidence rate is about 0.005%-0.008% Susceptible people: no special people Mode of infection: non-infectious Complications: ptosis, eye movement disorder
Cause
Causes of lacrimal gland pleomorphic adenoma
Cause:
A pleomorphic adenoma is one of the most common tumors in the oral and maxillofacial region. From the parotid epithelium. In addition to epithelial components, mucus and cartilage-like tissues are often found in tumors. Parotid mixed tumors occur in the parotid gland, followed by the ankle and submandibular glands. The clinical manifestations and treatment principles of the mixed tumor of the parotid gland are described below.
Pathophysiology
Polymorphic adenomas can be divided into three types according to different clinical and pathological manifestations, namely, cancer in pleomorphic adenoma, carcinosarcoma and metastatic pleomorphic adenoma. WHO is classified into three subtypes in the pleomorphic adenoma based on invasive growth and histopathological differentiation, ie non-invasive, aggressive, and carcinosarcoma (true malignant pleomorphic adenoma). For extremely rare, metastatic pleomorphic adenomas are simply mentioned. For some time, a "malignant pleomorphic adenoma" has often caused confusion in some people's understanding. It is better for Gnepp and Wenig to be clearly divided into the above three cases. The study believes that "cancer in pleomorphic adenoma" is a pathological descriptive term. From a clinical point of view, it is called "polymorphic adenoma malignant transformation" to express its characteristics.
Prevention
Lacrimal gland pleomorphic adenoma prevention
Light food, avoid fried, spicy, stimulating food, avoid tobacco and alcohol, hair, computer can be used, but try not to fatigue with the eyes.
Complication
Lacrimal gland pleomorphic adenoma complications Complications, ptosis, eye movement disorder
The ptosis, eye movement disorders and so on.
Symptom
Lacrimal gland pleomorphic adenoma symptoms common symptoms visual impairment eyeball protrusion ptosis hypospective nodules
Polymorphic adenomas have a longer course of disease, often more than 1 year, occurring in young adults aged 20-50 years, without spontaneous pain. Typical symptoms are painless masses in the lacrimal gland, slowly increasing, less pain, diplopia The most common symptoms are monocular progressive ocular protrusion and subtalar displacement. The outer upper part of the iliac crest can be hard and swollen. The surface of the lacrimal gland is palpated with granularity, no tenderness, no push, and eyelid swelling. A small number of patients have symptoms such as ptosis and eye movement disorder. The tumor oppresses the eyeball, produces astigmatism, vision loss, normal fundus or visible external upper indentation (choroidal retinal fold).
Benign polymorphic adenoma of the lacrimal gland is prone to recurrence. Most of the lesions invade extensively after recurrence, and may even cause bone destruction. Although histopathologically, it is still a benign tumor, the clinical manifestation of its biological behavior is malignant, recurring. The tumor can be nodular or irregular in the upper part of the ankle, tenderness, and the tumor can also spread to other locations of the eyelid, such as the upper part of the eyelid, the upper part of the upper part or even the lower part of the eyelid, away from the original position.
Examine
Examination of lacrimal gland pleomorphic adenoma
1. Pathological examination: The giant examination is a single multi-leaf mass, the tumor is round or elliptical, with a complete capsule, and the surface may have nodular protrusions, which is caused by the infiltration of the tumor cells, and the cut surface is light powder or Yellow-white, visible soft mucus-like area and fibrous tissue. Microscopically, the tumor tissue is mainly composed of epithelial cells or interstitial parts. It is composed of a large number of tubular structures and different cell nests composed of differentiated epithelial cells. Like, mucin-like, cartilage-like structural tumor cells in a variety of shapes and arrangements:
1 glandular tubular arrangement, there are two layers of cells, the inner layer is glandular epithelium, flat, cubic or cylindrical; the outer layer is myoepithelial cells, which are polygonal or fusiform.
2 solid block or strip-like arrangement, the tumor cells nest with water or cartilage-like areas, some epithelial nests can be seen squamous, electron microscopy shows two or more layers of epithelial cells forming a cavity, the inner surface of the cell surface It has fluffy hair, and the side has a complex connection with adjacent cells. The cytoplasm of these cells contains many mitochondria, rough endoplasmic reticulum and scattered tension filaments. Some cytoplasm tops contain a few round to oval, about 0.3m in diameter, medium electrons. Density, membrane-enclosed particles, basal cells have significant tension tow, have been confirmed as basal cells, and contain a few myoepithelial-like cells, which contain myofilament-like regions in the cytoplasm, interstitial inclusions around the cell islands. Cellular and extracellular components, including fibroblast-like cells, tissue cells, type II interstitial cells originating from the epithelium; extracellular components including collagen fibers, elastic fibers and fine fiber filaments and mucopolysaccharide-like substances, immune tissues Chemistry: Keratin (keratin), tumor ductal epithelial and mesenchymal epithelial-like cells occasionally stained, Muscle-specific actin (actin), tumor myoepithelial and vascular smooth muscle staining, occasional shuttle And groups of mesenchymal cells staining.
2. X-ray examination Because many modern imaging examinations such as ultrasound and CT are widely used, and the soft tissue lesions are superior to the traditional X-ray, the latter is still characteristic for the diagnosis of pleomorphic adenoma, and the X-ray can be displayed (20o before Position) cavity enlargement or lacrimal gland bulging outward, the boundary is clear and tidy, no bone destruction, because the tumor is located in the lacrimal gland adjacent to the bone wall and is restricted by the bone wall and the eyeball. After the tumor grows, the lacrimal gland is first pressed, causing the lacrimal gland to be outward. Expanded above, this X-ray sign has a qualitative diagnostic value.
3. Ultrasound examination of typical benign pleomorphic adenoma B-ultrasound showed a round or round-shaped lesion on the outer sac, with clear and smooth borders, moderate or moderate echo, uniform distribution, moderate sound attenuation, no compressibility Due to the enlargement of the lacrimal gland caused by tumor compression, the B-ultrasound shows a posterior prominent posterior segment of the tumor. This is a bone compression. These acoustic features are very consistent with the histological findings of pleomorphic adenoma. The outer upper part of the lesion, the entrance and exit of the tumor peak is higher, the inner is a uniform medium-high wave, moderate attenuation, very similar to the ultrasound characteristics of cavernous hemangioma.
CT scan CT scan has an important position in the diagnosis of lacrimal gland epithelial tumor. CT shows that the tumor is located in the lacrimal gland area above the iliac crest. The tumor is expansively growing, with round or round-shaped high-density block shadows. The boundary is clear and smooth. The internal density is basically homogeneous, and the pressure of the lacrimal gland can be changed (bone concave) and the lacrimal gland is enlarged. When the lesion is large, the coronary CT can show the absorption of the vault or the bone defect, but there is little obvious bone destruction. It is different from inflammatory pseudotumor or malignant lymphoma that occurs in lacrimal gland, and lacrimal gland enlargement is a characteristic change of benign lacrimal gland epithelial tumor. It is also one of the important indications for distinguishing from other lesions. The lesion mainly affects the lacrimal gland of the ankle, rarely affects the lacrimal gland of the ankle. The recurrent lacrimal gland is benign or flat in shape, which can invade the soft tissue around the eyelid (extraocular muscle, lifting the diaphragm) and bone. .
5.MRI diagnosis of benign pleomorphic adenoma is the same as other benign benign tumors. T1WI is a medium signal, T2WI is a high signal, but some tumors have a low T2WI signal, showing a middle signal, which is caused by scanning multiple angles. The spatial location is more clearly understood, and the enhanced scan shows a marked increase in the tumor. The recurrent tumor is irregularly shaped or nodular, and can also spread to the brain.
Diagnosis
Diagnosis and differentiation of lacrimal gland pleomorphic adenoma
According to the onset of monocular patients (20-50 years old), the painless mass of the upper iliac crest, CT showed a round shadow above the eyelid, clear boundary, high density, homogeneous or heterogeneous, can be enhanced by contrast agent No humeral destruction, B-mode ultrasound showed clear boundary of the tumor, regular shape, medium or strong internal echo, combined with clinical examination can make a diagnosis.
Differential diagnosis
Lacrimal adenoma
The tumor is medium in size, spherical in shape, non-adhesive to the skin and surrounding tissues, and can be moved and moved, with slow growth and abundant blood vessels. Color Doppler ultrasound and CT scans are helpful for diagnosis, and angiography can be similar to blood vessels.
2. Lacrimal gland lymphocytic disease
Occurred in the elderly, unilateral or bilateral onset, similar to inflammatory pseudotumor, a short history, the front of the palate can touch the solid mass, there is tenderness, ultrasound scan showed low echo in the lesion, the boundary is clear, less Sound attenuation, CT showed a large range of lesions in the upper temporal region, homogenization, and high density.
3. Lacrimal gland inflammation
Inflammatory pseudotumor often occurs in the lacrimal gland, clinical manifestations of swelling, pain, recurrent attacks, useful history of hormone therapy, ultrasound showing local lesions (flat) hypoechoic, CT scan showing semi-circular or flat lesions , often combined with adjacent extraocular muscle thickening or eye ring thickening, lesions often invade the lacrimal gland.
4. Dermoid cyst
It can occur in the lacrimal gland area above the eye. It is not easy to distinguish from the lacrimal gland tumor in clinical practice. The CT scan is mostly shown as a low-density area or a low-value area lesion can extend the visible bone depression to the sacral skull or dimple.
5. Other lacrimal gland lesions
Lacrimal gland cysts, schwannomas or granulomas are rare.
