A parotid neoplasm is a type of tumor, or abnormal growth, arising from the parotid salivary gland. The parotid gland is located in front of the ear and there are two glands, one on each side of the head. Of all the salivary glands, the parotids are most frequently affected by neoplasia, or abnormal cell growth. In most cases, a parotid neoplasm is found to be a non-cancerous, or benign, tumor. A malignant tumor is less common, and only around 20 percent of parotid neoplasms turn out to be cancer.
There may be few symptoms associated with a parotid neoplasm. Often, the only sign might be a painless lump in the cheek. A lump which grows slowly over a long period is more likely to be benign. Malignant parotid neoplasms may be attached to the skin and surrounding structures. A skin ulcer could develop over the tumor, which may feel very hard.
Sometimes pain is experienced, and this can be a sign of malignancy where a tumor is affecting a nearby nerve. Pain does not necessarily indicate cancer because other conditions, such as infections, can also result in a painful parotid gland. In cases where a malignant tumor is invading a nerve, this can sometimes cause paralysis of part of the face.
Diagnosing a parotid neoplasm involves examining the tumor and asking the patient about its history. A sample of neoplastic cells may be taken using a fine needle. These can then be inspected using a microscope. Imaging scans, using technology such as computerized tomography (CT), can help establish a diagnosis. The most common type of benign parotid neoplasm is known as a pleomorphic adenoma, while the most frequently occurring malignant tumor is called mucoepidermoid carcinoma.
In many cases, the treatment of a parotid neoplasm is combined with the diagnosis, and the whole lump is removed and assessed for signs of cancer. The surgeon removes the tumor together with the surrounding area of the parotid gland, taking care to avoid damaging the facial nerve which controls the muscles of facial expression. Sometimes the surgeon may use a nerve stimulator to check that the facial nerve is intact throughout the operation. The outlook for a parotid neoplasm depends on whether it is benign or malignant, as a benign tumor generally leads to a positive outcome. Some types of malignant tumor have a better prognosis than others, especially if they are discovered and removed before they have spread.