What Is Adenoid Cystic Carcinoma?

Adenoid cystic carcinoma is also called cylindrical tumor or cylindrical tumor type adenocarcinoma. Adenoid cystic carcinoma accounts for 5% to 10% of salivary gland tumors, and 24% of salivary gland tumors. Occurs in the salivary glands, often occurring in the glandular glands. Although the salivary gland is relatively small, it is a tumor that occurs frequently in the submandibular and sublingual glands. Only 2% to 3% of the parotid tumors. There was no significant difference in incidence between men and women, or slightly more women. The most common age is 40 to 60 years.

Basic Information

English name: adenoid cystic carcinoma
Visiting department: Oncology
Multiple groups: 40 to 60 years old women are slightly more

Common locations: Lacrimal gland
Common causes: Salivary duct, basal cell metastasis of oral mucosa
Common symptoms: Pain, palpable adhesive mass with orbital margin, unclear border may be tenderness

Causes of adenoid cystic carcinoma

First reported by Billroth and called a cylindrical tumor. Most people think that tumors come from salivary ducts, and they may also come from the basal cells of the oral mucosa.

Clinical manifestations of adenoid cystic carcinoma

Adenoid cystic carcinoma accounts for 5% to 10% of salivary gland tumors, and 24% of salivary gland tumors. Occurs in the salivary glands, often occurring in the glandular glands. Although the salivary gland is relatively small, it is a tumor that occurs frequently in the submandibular and sublingual glands. Only 2% to 3% of the parotid tumors. There was no significant difference in incidence between men and women, or slightly more women. The most common age is 40 to 60 years.

Most of the early tumors are painless masses, and a few cases have pain when found, and the pain is intermittent or persistent. Some pains are mild and some may be severe. The course is longer, months or years. Tumors are generally small, mostly 1 to 3 cm. The shape and characteristics of the mass can be similar to mixed tumors, round or nodular, and smooth. The boundary of most masses is not very clear, the mobility is poor, and some are relatively fixed and have adhesions to surrounding tissues. Tumors often spread along the nerve. Adenoid cystic carcinoma that occurs in the parotid gland can cause facial nerve palsy, and can spread along the facial nerve to affect the mastoid and temporal bone. The inferior nerve spreads far away from the primary tumor and causes affected tongue perception and dyskinesia; adenoid cystic carcinoma that occurs in the palate can expand into the skull along the maxillary nerve, destroying bone at the skull base and Severe pain. Tumors often invade adjacent bone tissue, such as those that occur in the submandibular and sublingual glands often involve the mandible; those that occur in the crotch often involve the sacrum. Occurred in small salivary adenoid cystic carcinoma involving the mucosa, in addition to touching the hard texture, small nodular masses, often visible, reticular expanded capillaries.

Examination of adenoid cystic carcinoma

Laboratory inspection

Histopathological changes: no intact capsules, gray section or small cystic changes with bleeding. Under light microscopy, columnar basal-like cells constitute 5 types of histological images, including sieve-like (swiss cake-like); tubular; solid type; acne type;

2. Other auxiliary inspections

(1) X-ray examination No special findings in the early stage, the lacrimal gland enlargement and osteolytic bone destruction can be seen in the later stage.

(2) Ultrasound B-ultrasonography showed a lesion in the lacrimal gland area, which was flat or spindle-shaped, with clear boundaries, uneven internal echo, moderate sound attenuation, and irregular posterior boundary of the tumor. A-ultrasound showed that the internal reflection of the lesion was irregular and the attenuation was obvious. Doppler scans show abundant blood supply within the tumor.

(3) CT scan CT scans of adenoid cystic carcinoma have more special signs, which are mostly high-density space occupying lesions above the orbit, and the shape is flat spindle or irregular. The growth of the lesion along the outer wall of the orbit to the orbital apex has a significant enhancement. There can be no bone destruction at an early stage. This kind of growth is relatively unique, accounting for more than 80% of cases. Some lesions spread through the supraorbital fissure to the late intracranial stage, and the lesions infiltrated the bone and caused bone destruction.

(4) MRI examination The tumor showed a low-to-medium signal on T1WI, and a high or medium-to-high signal on T2WI, and the enhancement was obvious. Tumors have a wide range on MRI. The hemorrhagic and necrotic spaces that invade bone and surrounding structures, such as intracranial temporal fossa tumors, show moderate to high heterogeneity on TlWI. Because bone has no signal on MRI, especially on T1WI, if the tumor is a medium signal, the bone is not well displayed when the signal is low, while on T2WI, the general tumor signal is high. At this time, bone destruction with low signal is better. display.

Adenoid cystic carcinoma diagnosis

Adenoid cystic carcinoma, like other types of salivary gland tumors, is difficult to diagnose before surgery. In patients with salivary gland masses with early pain and neuropalsy, the diagnosis of adenoid cystic carcinoma should be considered first. To further confirm the diagnosis, fine needle aspiration cytology can be performed. Under the microscope, tumor cells are round or oval, similar to basal cells, and aggregated in pellets. Mucus is pelletized, with one or more layers around it. Layer of tumor cells. This unique manifestation is not found in other salivary gland epithelial tumors, which can be diagnosed as adenoid cystic carcinoma with this feature.

Adenoid Cystic Carcinoma Treatment

Surgical resection is still the main method for the treatment of adenoid cystic carcinoma. The surgical design should enlarge the normal boundary of the operation than other malignant tumors, and a frozen section examination should be performed during the operation to determine whether the surrounding tissues are normal. Radiation therapy is often required after surgery to kill possible residual tumor cells. Chemotherapy can be used to prevent blood tract metastasis. Local mass resection is the main principle for radical adenoid cystic carcinoma, that is, to remove as much of the surrounding tissue as possible when the function is not affected. In principle, a total parotid gland resection is performed for adenoid cystic carcinoma. Considering the high neuroinvasiveness of adenoid cystic carcinoma, the reservation of facial nerves should not be considered excessively; those with submandibular glands should undergo at least submandibular dissection; it occurs in the palate Patients should consider subtotal or total resection of the maxilla. If the zygomatic foramen has been violated, the pterygopalatine canal should be resected together with the flap, and if necessary, a skull base resection can be performed.

The cervical lymph node metastasis rate of adenoid cystic carcinoma is about 10%, but the direct invasion is far more than that of tumor thrombus metastasis. Allen and Bosch studied the regional lymphatic metastasis of adenoid cystic carcinoma and concluded that the so-called lymph node metastasis is that the tumor directly invades the lymph nodes, and the surrounding soft tissues are infiltrated with tumor cells, and no cases of tumor metastasis have been seen. Therefore, patients with adenoid cystic carcinoma do not need to undergo selective lymphadenectomy.

In addition to extensive resection of recurrent or advanced tumors, radiation therapy can be used after surgery. In some anatomical areas, surgery cannot be completed thoroughly, but also requires radiation therapy. Surgery combined with radiation therapy may reduce the recurrence rate. For some cases where surgery is lost, radiation therapy can also be used to control development.

Advanced patients or patients with recurrence after surgery can also be combined with chemotherapy to reduce recurrence. Chemotherapy is mainly used in conjunction with surgery or palliative care.

Prognosis of adenoid cystic carcinoma

The location of the lesion, the size of the tumor, and whether the surgical procedure is completely removed are directly related to the patient's prognosis. Adenoid cystic carcinoma is prone to recurrence locally, and multiple recurrences often occur distantly. The main cause of death was local damage or distant metastases. The tumor develops slowly, and even if it recurs, it can survive for many years.