Cheilitis and Glossitis

Infectious inflammations (Sialadenitis)

Based on etiology and course, sialadenitis is divided into bacterial and viral, as well as acute and chronic. Primary forms (occurring independently) and secondary forms (developing as a complication) are distinguished, with the latter being diagnosed significantly more often. Infection can enter the gland via three pathways: stomatogenic (ascending through the ducts), lymphogenous, and hematogenous.

Acute purulent sialadenitis most commonly affects the parotid gland, causing acute purulent parotitis. The main causative agents are Staphylococcus aureus and group A streptococci, which enter through the excretory duct. The main predisposing factor is a decrease or complete cessation of salivation. This occurs against the background of water-electrolyte imbalance (due to high fever, diuretics, starvation) or after abdominal surgery.

Chronic sialadenitis is predominantly localized in the submandibular gland. Its development is associated with obstruction of the excretory ducts by stones or strictures, which increases tissue susceptibility to retrograde bacterial infection. During an exacerbation, the disease progresses to purulent inflammation.

Complications of purulent forms include phlegmon and abscesses of the surrounding soft tissues with the formation of fistulas opening onto the skin or into the oral cavity. The outcome of the disease is the development of sclerosis or cirrhosis of the gland. Clinically, cirrhosis may resemble a neoplasm, which is known as Küttner tumor.

Viral and specific lesions

Specific sialadenitides are caused by specific flora and are classified into actinomycotic, tuberculous, and syphilitic.

Viral lesions are provoked by Coxsackie viruses, Epstein-Barr virus, influenza, and others, but mumps virus and cytomegalovirus are of the greatest clinical significance. In cytomegaloviral parotitis, lymphomacrophage infiltration is observed in the stroma and parenchyma. Individual epithelial cells of the ducts and acini enlarge significantly (cytomegalia). Large purple intranuclear and small basophilic cytoplasmic inclusions appear within them. A pathognomonic sign is a halo of cytoplasmic clearing around the nucleus, giving the affected cell a characteristic «owl-eye» appearance.

Radiation-induced (iatrogenic) injuries, which occur after therapy for malignant tumors of the head and neck, are distinguished separately. The serous acini of the parotid gland have the highest radiation sensitivity. The acute inflammatory reaction eventually transitions into chronic sclerosing sialadenitis.

Obstructive lesions

Obstructions develop due to duct blockage by stones, external compression, ligation, or duct kinking. The main nosologies include:

1. Sialolithiasis (salivary stone disease) is a chronic disease characterized by the formation of calcium salts. Desquamated cells and mucin serve as the matrix for the stone. The three main pathogenetic factors are: secretion stasis, a shift in saliva pH toward the alkaline side (up to 7.1–7.4) with increased viscosity, and infection. The disease is accompanied by gland swelling and «salivary colic»—pain during meals. Progression leads to parenchymal atrophy, squamous or oncocytic metaplasia, and cyst formation.
2. Mucocele is a mucous cyst up to 1 cm in size, arising from trauma to the ducts of minor salivary glands. Large mucoceles of the floor of the oral cavity are called ranula.
3. Retention cyst is a cystic dilation of the duct due to its blockage or compression.

Autoimmune and tumor-like processes

Autoimmune pathologies include Sjögren's syndrome (keratoconjunctivitis sicca, xerostomia, and systemic disease) and Sjögren's disease (isolated lesion with antibodies against duct epithelium).

Among tumor-like lesions, the following are distinguished:

• Sialoadenosis (sialosis) is a bilateral non-inflammatory enlargement of the parotid glands associated with hormonal disorders, leading to lipomatosis.
• Oncocytosis is a cellular transformation, most commonly in the parotid gland.
• Necrotizing sialometaplasia is acinar necrosis with squamous metaplasia in minor glands, regressing within 6–10 weeks.
• Benign lymphoepithelial lesion (Mikulicz's disease) is the replacement of glandular parenchyma by a lymphoid infiltrate with a high risk of developing lymphoma or carcinoma.
• Lymphoepithelial cysts of the parotid glands, often associated with HIV infection.

Salivary Gland Tumors

Salivary gland tumors account for up to 4% of all human neoplasms. The parotid gland is most frequently affected (64–80%), with the peak incidence occurring in the 6th–7th decades of life. More than half of all tumors are benign.

The most common of these is pleomorphic adenoma. It presents as a painless nodule ranging from 1 to 10 cm, surrounded by a fibrous capsule. On cross-section, the tissue is whitish-yellow with small cysts and dense cartilage-like areas.

The tumor frequently recurs (especially with a myxoid component) because its thin capsule is easily damaged during surgery. An additional difficulty for the surgeon is the risk of injuring the facial nerve passing through the parotid gland. Recurrent adenomas often acquire a solid structure and have a pronounced tendency toward malignant transformation.

Briefly: answers to topical questions

Class and exam questions

What else to study on this topic

• Histological variants of pleomorphic adenoma
• Pathogenesis of Sjögren's syndrome and systemic associations
• Benign lymphoepithelial lesion (Mikulicz's disease)
• Morphological characteristics of viral sialadenitis

Other Topics in "Chapter 27. Diseases of the Dentofacial System and Oral Cavity"

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