Dott.re Giuseppe Spinelli

Cancer of the parotid and salivary glands

INTRODUCTION TO THE TUMOR OF PAROTID AND SALIVARY GLANDS

Oncological Surgery

Tumors of the salivary glands, organs that produce saliva, are not common and represent only 2-3% of head cancers. The salivary glands are divided into major salivary glands (parotid, under mandibular and sublingual) and minor salivary glands dispersed in the mucosa of the upper portion of the aerodigestive tract. Parotid and salivary gland tumors, jaw neck cheek section. Salivary gland tumors can also be distinguished in minor salivary gland tumors and parotid tumors.

70% of salivary gland tumors originate from the parotid glands, the rest originate from the submandibular glands (8%) and from the minor salivary glands (22%).

75% of parotid tumors are benign (exclusively local symptoms), while more than 50% of tumors in the submandibular glands and even more than 80% of minor salivary gland tumors are malignant (tumors that also give systemic symptoms).

Parotid cancer in 85% of cases is a pleomorphic adenoma, which is more common in women than men, with a peak incidence in the third and fourth decades of life.

Whartin’s cystadenolymphoma is the second most common cause of parotid cancer, accounting for between 5-15% of these tumors. This type of parotid tumor is more common in men than women and affects between the fifth and sixth decade. Mucoepidemoid carcinoma is the most common parotid tumor. As for the minor salivary glands up to 80% they can be malignant, the most frequent histotype is adenoidocystic carcinoma.

ETIOLOGY OF THE TUMOR OF PAROTID AND SALIVARY GLANDS

Although the etiology is fundamentally unknown, it has been noted that some agents correlate with the onset of salivary gland tumors and parotid tumors.

Exposure to radiation has been linked to the development of parotid cancer. Epstein-Barr virus may be a factor in the development of lymphoepithelial tumors of the salivary glands. Even genetic alterations such as allelic loss, monosomy, polysomia and structural rearrangements of chromosomes have been related to tumors of the salivary glands and especially to parotid tumors.

PRESENTATION THE SALIVARY GLAND NEOPLASMS

The increase in the volume of the gland is certainly the most important clinical sign to suspect the presence of a tumor of the salivary glands and in particular of the parotid tumor. This dimensional variation of the gland (s) must be put into differential diagnosis even with other non-neoplastic diseases such as inflammatory and infectious phenomena and the calculations of the salivary ducts. A deficiency of the facial nerve, poor mobility of the mass, overlying red and dystrophic skin make us suspect the malignant nature of the tumor.

The physical examination to identify a tumor of the salivary glands or a parotid tumor must take into consideration the position, the size, the speed of growth, the possible symptoms in relation to the meals, the deficiency of the facial nerve.
For parotid tumors that occur at the level of the deep lobe, we can have an atypical presentation characterized by disorders of swallowing (dysphagia) and language (dysphonia).

DIAGNOSIS OF THE TUMOR OF PAROTID AND SALIVARY GLANDS

Ultrasound is a technique that can be used to diagnose, delineate the localization, vascularization and margins of tumors of the salivary glands and in particular the parotid tumor.

It can also be used to guide the aspirated needle to collect a biopsy sample.

Instrumental investigations such as computed tomography (CT) and nuclear magnetic resonance (NMR) with and without contrast represent second-level investigations and are often necessary for the evaluation of the tumor size of the parotid gland, extraglandular extension and margins and for assess the possible lymph node involvement.

CT can also be used to guide the biopsy in some tumors of the salivary glands and in particular for the parotid tumor, otherwise difficult to reach (eg parapharyngeal space). MRI ensures greater detail in the study of soft tissues and often results in a diagnostic deepening necessary in intervention planning.

THERAPY THERAPY OF PAROTIDES

OF SALIVARY GLANDS

Surgery in salivary gland tumors and parotid tumors.

Surgery has a fundamental role in the treatment of tumors of the salivary glands and in particular for the parotid tumor. Surgery is different depending on the nature of the neoplasm and the type of gland involved. In the case of benign tumor of the parotid the most frequent intervention consists in the removal of the neoplasm surrounded by healthy salivary tissue or by the removal of the superficial portion of the gland, both procedures must pay particular attention to the facial nerve that separates the superficial portion from that deep gland.

If the benign parotid tumor affects the other major or minor salivary glands, the surgical procedure consists in the removal of the gland or neoplasm surrounded by healthy tissue in the case of minor salivary glands.

The malignant nature of the parotid tumor radically changes surgical treatment: the resection margins must be wider and depending on the histotype it may be indicated to proceed with a laterocervical emptying (removal of the lymph nodes of the neck in which the tumor drains). In these cases if there are clinical signs (paresis), radiographic (contiguity) and / or surgical (nerve involvement) of involvement of the facial nerve the surgical intervention must include the removal of the nerve and its simultaneous reconstruction with a nerve graft.

Radiotherapy in salivary gland tumor and parotid tumor.

Radiotherapy, in tumors of the salivary glands and in parotid tumors, can be used after surgery (adjuvant therapy) for those tumors that are classified as malignant, it can also be used as an approach for those tumors that are considered unresectable surgically.

Chemotherapy in salivary gland cancer and parotid tumor.

Tumors of the salivary glands and tumors of the parotid are not very sensitive to chemotherapy and this is to be considered exclusively palliative.

Clinical cases
Case 1 - Cancer of the parotid CANCER SURGERY - Warning, contains images of intervention

Pleomorphic adenoma – parotidectomy and fat grafting

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Preoperative image with evidence of swelling in the right parotid region – pleomorphic adenoma of the deep lobe

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The main trunk of the facial nerve and the marginal branch at the bottom right – in the acute corner we can see the adenoma of the deep lobe.

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Split the superficial parotid to access the deep lobe located between the branches of the facial nerve.

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Operative pieces – on the left the pleomorphic adenoma, on the right the portions of parotid gland splitted and subsequently removed separately

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The removal of dermograsso from the sobrapubic region to fill the surgical defect.

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The dermograsso graft in place fixed with resorbable sutures.

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Immagine postoperatoria con buona simmetria facciale – lieve edema residuo dei tessuti molli in regione parotidea destra.

Caso 2 - Cancer of the parotid CANCER SURGERY - Warning, contains images of intervention

Pleomorphic adenoma – parotidectomy

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Preoperative image with swelling at the level of the mandibular and parotid region

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At RMN, pleomorphic adenoma, right parotid gland – typically plurilobulated appearance.

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Intraoperative detail with pleomorphic adenoma that is excised with the parotid gland after isolation and conservation of facial nerve branches

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At the end of the operation, the facial nerve and its branches – down the branch of the great auricular nerve for sensitivity, both preserved.

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Postoperative image with restoration of the normal symmetry of the face.

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The scar (face-lift type incision) is not very visible and is in fact well masked by the auricle and the hair

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Salivary glands neoplasms