Mixed salivary gland tumor

Brief introduction of parotid mixed tumor Mixed tumor of salivary gland (mixed tumor of salivary gland) is a benign tumor that occurs in the large parotid gland and small parotid gland, can occur at any age, more common in 30-50 years old. There is no significant difference between male and female, because it occurs in the outer and middle ovules, the tumor contains epithelial tissue, connective tissue, muscle tissue and myxoma-like tissue. Therefore, Minssen (1896) called it a mixed tumor, also known as pleomorphic adenoma. (Pleomorphicadenoma). Mixed tumors are not absolutely benign and are low-grade malignant tumors, also known as critical tumors. basic knowledge The proportion of sickness: 0.0052% Susceptible people: no specific population Mode of infection: non-infectious Complications: facial paralysis

Parotid mixed tumor etiology

Causes:

Mixed tumors often occur in the parotid gland, followed by the ankle, submandibular gland, sublingual gland, cheek, mouth, and lips. The tumor is derived from the ectoderm and mesoderm. It is round or lobulated, with intact or incomplete capsules. The cut surface is grayish white, partially translucent mucus, and sometimes cartilage.

Pathogenesis:

Microscopic examination showed that some of the tumors were epithelial cells with different cell morphology, mostly cuboidal or polygonal, which could be basal cell-like, or squamous epithelium. Cells were arranged in multiple cords or patches, or composed of different sizes. The cystic cavity, or most of the scattered glands, between the epithelial cell mass, has fibrous tissue, and often has transparency. In addition, there are mucous tissue and cartilage-like, bone-like tissue, of which mucus tissue is most prominent, and mucous cells can be Star-shaped, fusiform or polygonal, sometimes visible epithelial cells transition to mucous cells, cartilage tissue in the tumor is similar to normal tissue, but most of the differentiation is incomplete, similar to mucus tissue (Figure 1), there are often tumors in the capsule Buds, so the tumor has a clear tendency to relapse.

Parotid mixed tumor prevention

For the prophylactic anti-infection of general surgery, sulfa drugs (such as compound sulfamethoxazole) or drugs mainly acting on Gram-positive bacteria (such as erythromycin, penicillin, etc.) are used. People with poor constitution or concurrent infections often use drugs. More commonly used: drugs that act on Gram-positive bacteria (such as penicillin) plus drugs that act on Gram-negative bacteria (such as gentamicin) plus drugs that act on anaerobic bacteria (such as metronidazole); surgery Patients with severe infections or complications before and after can choose effective antibiotics according to clinical and drug susceptibility tests.

The mixed tumor of the parotid gland must be treated surgically. It is not sensitive to radiation and generally cannot be treated with radiotherapy. Because the tumor is a critical tumor, the tumor can survive for a long time or improper treatment, and it can cause malignant transformation. Therefore, once the tumor of the parotid gland is found, Surgical resection should be promptly performed. It is forbidden to use some externally applied drugs with unknown ingredients. The tumor generally grows slowly and can be asymptomatic for a long time. However, if growth is accelerated, the hardness increases, etc., it means malignant transformation, and surgery should be performed immediately, but the operation after malignant transformation The prognosis is far less than the prognosis of benign surgery.

Parotid mixed tumor complications Complications

The mixed tumor in the oral cavity has no self-conscious symptoms in the early stage. When it increases, it can cause dysfunction such as chewing, swallowing, and language breathing. For example, mixed tumors may cause ulceration due to food friction, etc., and may cause oral and maxillofacial infections, oral cavity. Diseases such as maxillofacial tumors.

Parotid mixed tumor symptoms Common symptoms Cervical lymphadenopathy Persistent pain Slow growth Skin adhesion Pharyngeal foreign body sensation Facial nerve palsy

1. Parotid mixed tumor: more than 80% of parotid mixed tumors occur in the parotid gland, most of which are located in the parotid gland, which is characterized by tissue bulging in the parotid gland, especially the earlobe, the most common in the posterior region, with smooth surface or nodules. Protrusion, painless, the hardness of the tumor is also inconsistent, pushable can move, does not adhere to deep tissue and skin, 1/10 occurs in the deep parotid gland, often manifested as parapharyngeal soft tissue to the midline bulging deformity, much like from The tumor of soft palate grows, when the volume is small, it is often asymptomatic. The patient occasionally has a foreign body sensation of the pharynx. After the deep mixed tumor of the parotid gland grows, the lateral mandibular ascending branch can be compressed, and the posterior temporomandibular region is bulged into the deep part of the parotid gland. The mixed tumor, because the tumor growth is limited by the pterygopalatine ligament, the activity is not large, the tumor is often dumbbell-shaped.

2. Submandibular gland mixed tumor: There is a mass in the submandibular triangle area, the surface is smooth or nodular, and the push can move.

3. Small parotid mixed tumor: can occur in various parts of the mouth, mostly at the junction of hard and soft palate, the tumor is a painless mass, slow growth, mostly spherical, clear perimeter, mostly moderate medium hardness, nodules on the surface , no adhesion to the surrounding tissue, the activity is generally good, and the mixed tumor located in the tongue is very poor mobility, especially the mixed tumor of the hard palate and the periosteum adhesion fixation.

According to reports, the malignant rate of parotid mixed tumors was as high as 34.6%. One hospital affiliated to Hunan Medical University analyzed 169 cases of mixed parotid gland tumors, 17 cases of malignant transformation, and the malignant rate was 10%.

Mixed tumors suddenly increase in the process of growth, tumors and deep tissues and skin fixation, the boundaries are not obvious, local persistent pain, facial nerve spasm, and cervical lymph nodes are enlarged or fixed, malignant changes should be considered.

Mixed tumor malignant transformation is often based on recurrence, because the tumor tissue under the first surgery remains, such as a tumor tissue outside the tumor capsule, or another tumor nodule with only thin strips and main tumor Connected, not easy to detect; because the capsule is incomplete, the tumor tissue is implanted during surgery, and the mixed tumor can also accelerate the development of the tumor and promote malignant transformation due to trauma, inappropriate acupuncture, and ulceration after infection with corrosive drugs. .

Parotid mixed tumor examination

1, clinical examination

First of all, pay attention to observe whether the necks on both sides are symmetrical, whether there is local swelling, fistula formation, etc., and then the neck is diagnosed. The examinee has a slightly lower head and tends to the disease side, which makes the neck muscles loose and facilitates the mass. Touching, pay attention to the location, size, texture, activity of the mass, whether there is tenderness or pulsation, and should be compared with the two sides. As mentioned above, adult neck masses should consider metastatic malignant tumors. Therefore, Routine examination of the ear, nose, throat, mouth, etc., in order to understand whether there is a primary lesion in the nasopharynx, throat, etc., if necessary, can be used for nasal endoscopy or fiberoptic nasopharyngoscopy.

2, imaging examination

(1). B-mode ultrasound can be used as a routine examination method for parotid masses, which can determine the actual size of the tumor. It can also roughly distinguish its benign and malignant according to the internal echo and its relationship with the perimeter, and the benign manifestation is clear. The internal echo is homogeneous, and the posterior wall is enhanced; the malignant tumor is unclear, the internal echo is uneven, and even the strong light group appears, but the qualitative ability is still not strong.

(2). Parotid gland angiography is mainly represented by the pushing displacement of the catheter system and glands.

(3). CT and MRI examination occurred in the parapharyngeal space, CT and MRI examination can provide stereoscopic images of the tumor, the relationship between the tumor and the parotid gland and surrounding tissue structure, and help to distinguish other tumors in the parapharyngeal area .

3, pathological examination

(1) Puncture biopsy: a small needle is inserted into the mass, and the tissue obtained after vigorous aspiration is examined for cytopathology. It is suitable for most neck masses, but the tissue obtained is less. When the test is negative, it should be combined. Further examination in clinical practice.

(2) Incision biopsy method: should be used with caution, generally only when the diagnosis is not confirmed after repeated examinations, the single lymph node should be taken out completely during operation to prevent the spread of the lesion, suspected tuberculous cervical lymphadenitis, cut After the biopsy, there is a possibility that the wound will not be cured for a long time. It should be prevented. For patients with clinical diagnosis of parotid or neurogenic benign tumors, due to the deep tumor location, preoperative biopsy is not easy to obtain positive results, but there are Adhesion of the tumor to the surrounding tissue, increasing the difficulty of surgery, it is generally sent to the pathological examination after surgical removal of the tumor.

Diagnosis and differentiation of parotid mixed tumor

Diagnose based on

1. A painless mass in the parotid gland, which grows slowly.

2. The small surface of the tumor is smooth, the larger is nodular, the texture is moderately hard, no tenderness, activity (occurs in the parotid gland can not be active), no facial paralysis.

3. Parotid gland angiography showed benign space-occupying lesions.

4. B-type ultrasonic waves see the smooth reflection image of the realm, and the internal echo wave distributes the light spot evenly.

According to the medical history, clinical manifestations and parotid angiography, a preliminary diagnosis can be made. Usually, the biopsy is not recommended before surgery. Because of the incision of the capsule, there is a risk of implanting tumor cells, increasing the recurrence rate, and can be used for needle biopsy or intraoperative. frozen slice.

Differential diagnosis

1. Epidemic mumps:

The incubation period is 8 to 30 days, with an average of 18 days. Most of the onset is more urgent, no prodromal symptoms, fever, chills, headache, sore throat, poor appetite, nausea, vomiting, body aches, etc., several hours of parotid swelling and pain, gradually Obviously, the body temperature can reach above 39 °C, and adult patients are generally more serious.

The swelling of the parotid gland is the most characteristic. It is generally centered on the earlobe. It develops forward, backward, and downward. It is shaped like a pear and has unclear edges. The skin is tight, shiny but not red, and it is tough and elastic. Pain; speech, chewing (especially in an acidic diet) stimulates salivation, leading to increased pain; usually one side of the parotid gland swelling 1 to 4 days involving the contralateral side, bilateral swelling accounted for about 75%, submandibular gland or sublingual gland can also At the same time, the severe tissue of the parotid gland is highly edematous, which makes the appearance deformed, and dysphagia may occur. The opening of the parotid gland may be red and swollen at the early stage, and the abscess of the parotid gland is always overflowing from the opening. The swelling of the parotid gland is mostly 1 3 days to reach the peak, lasting 4 to 5 days gradually subsided and returned to normal, the whole process is about 10 to 14 days, the submandibular gland and sublingual gland can also be affected at the same time, or appear alone, the submandibular gland is swollen, which is characterized by swelling of the anterior and lower jaw. Touching the enlarged gland, the sublingual gland enlarges and the tongue and the bottom of the mouth are swollen, and dysphagia occurs.

2, submandibular space infection: clinical manifestations, odontogenic infection process rapid development, systemic hyperthermia, swelling in the submandibular area clear, skin congestion, redness, sometimes bright, depressed edema and tenderness, early abscess formation, It can be awkward and fluctuating; the development of glandular disease is slow, and the initial inflamed induration is gradually growing up. After penetrating the lymph node capsule, it is diffuse cellulitis. The symptoms are the same as odontogenic infection, but only in the late stage. Form an abscess.

3, submandibular cystic water tumor: common in infants and young children, puncture examination can be seen that the contents of the cystic cavity is thin, no mucus, light yellow clear, smear microscopic examination of lymphocytes.

All types of mixed tumors need to be identified with the following diseases:

1. Identification of mixed tumors of the parotid gland

(1) Parotid cyst: slow growth, normal skin surface, small volume, clear boundary, soft, can extract clear yellow liquid.

(2) eosinophilic lymphogranuloma: occurs in the parotid gland, often with unilateral or bilateral multiple masses, slow growth, early soft rubbery, gradually tough, unclear border, mass The skin of the area is pigmented, dry and rough, closely adhering to the tumor, and often has a shallow scar left after the tumor collapses, the superficial lymph nodes can be swollen, and the eosinophils in the blood are increased.

(3) Parotid tuberculosis: early parotid lymph node involvement, slow growth, after the lymph node is perforated, invading the parotid gland, clinical manifestations are very similar to tumors, some are cystic or have a sense of fluctuation, a few patients with parotid ducts may have purulent discharge, Some patients have a history of lymphatic tuberculosis or tuberculosis in the neck, and anti-tuberculosis treatment is effective, which can help differential diagnosis.

(4) M. serovar and Sjogren's syndrome: all can involve the parotid gland, lacrimal gland and submandibular gland, mostly bilateral bilateral symmetry enlargement, dry mouth, parotid gland enlargement, dry keratitis as a common feature, dry Syndrome and other connective tissue diseases, such as rheumatoid arthritis, the relationship between the two is still unclear, some people think that M. sinensis is an early manifestation of Sjogren's syndrome, it is considered to be an autoimmune disease, no parotid mass Pain, hard, sputum reduction and dry mouth discomfort.

(5) Symptomatic parotid swelling: diffuse enlargement of the parotid gland, soft, often bilateral, with no symptoms, can occur with nutritional disorders, diabetes, chronic hepatitis, cirrhosis and other chronic diseases.

(6) simple parotid swelling: more common in adolescent males, may be related to growth and development, no adverse consequences, mostly temporary, a small amount of swelling due to excessive time, become a constant parotid swelling.

(7) ganglion cell tumor: originated from the sympathetic ganglia, mostly in children under 10 years old, the tumor is located in the upper neck, the anterior aspect of the sternocleidomastoid muscle, the tumor is spherical or spindle-shaped, can not move up and down It can move horizontally, and the touch is hard and tough, and it can be accompanied by cervical sympathetic paralysis syndrome.

2. Identification of submandibular mixed tumor

(1) Cleft palate cyst: occurs mostly in the lower pole of the parotid gland or between the sternocleidomastoid muscle and the mandibular angle. It grows slowly, is active, smooth, and sometimes has a sense of turbulence. It can extract milky white or clear liquid.

(2) Chronic submandibular gland inflammation: due to prolonged inflammatory stimulation to make the glandular fibrosis, the gland is a hard mass at the time of palpation, there is a history of progressive gland enlargement, when the gland is massaged, the secretion of the duct is less or no, there may be The purulent viscous liquid flows out.

(3) Submandibular lymphatic tuberculosis: similar to lymphatic tuberculosis of the parotid gland.

(4) Low-grade malignant tumor of the submandibular gland: mostly adenoid cystic carcinoma, mucoepidermoid carcinoma, general history is also long, can be several years, more than 10 years, the tumor grows slowly, the shape of the tumor is irregular, and can also be knotted Nodules, early asymptomatic, similar to mixed tumors, but the general activity is poor, the former is easy to invade the nerve with pain, the latter can be solid or cystic, cystic people generally better differentiation.

3. Small parotid mixed tumors should be differentiated from mucoepidermoid carcinoma and adenoid cystic carcinoma.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.