Читать книгу Salivary Gland Pathology - Группа авторов - Страница 115

Most non‐neoplastic swellings of the major salivary glands represent acute or chronic infections of these glands. Sialadenitis, a generic term used to describe infection of the salivary glands, has a diverse range of signs and symptoms and predisposing factors. Although any of the major and minor salivary glands can become infected, these conditions most commonly occur in the parotid (Figure 3.1) and submandibular glands (Figure 3.2), with minor salivary gland and sublingual gland infections being very rare. From an etiologic standpoint, these infections may be related to underlying bacterial, viral, fungal, mycobacterial, parasitic, or immunologically mediated inflammation/infections (Miloro and Goldberg 2002). The most common of these diagnoses include acute bacterial parotitis and acute submandibular sialadenitis (see Table 3.1). Numerous risk factors may predispose patients to sialadenitis. The classic risk factor is the hospitalized patient who recently underwent surgery with general anesthesia. Additionally, dehydration (insufficient intake) may contribute to sialadenitis, as may chronic nausea/vomiting (excessive output) in hospitalized patients. Both conditions decrease intravascular volume, thereby decreasing perfusion of salivary gland tissue with resultant decreased salivary flow. In general terms, stasis and decreased salivary flow predispose patients to sialadenitis, although, medications and comorbid diagnoses may also contribute to this diagnosis (see Table 3.2).

Figure 3.1. A 55‐year‐old woman (a and b) with a one‐week history of pain and swelling in the left parotid gland. No pus was present at Stensen duct. The diagnosis was community acquired acute bacterial parotitis. Conservative measures were instituted including the use of oral antibiotics, warm compresses to the left face, sialogogues, and digital massage. Two weeks later, she was asymptomatic, and physical examination revealed resolution of her swelling (c and d).

Figure 3.2. A 45‐year‐old man (a) with a six‐month history of left submandibular pain and swelling. A clinical diagnosis of chronic submandibular sialadenitis was made. A screening panoramic radiograph was obtained that revealed the presence of a large sialolith in the gland (b). As such, the obstruction of salivary outflow by the sialolith was responsible for the chronic sialadenitis. This case underscores the importance of obtaining a screening panoramic radiograph in all patients with a clinical diagnosis of sialadenitis, as it permitted expedient diagnosis of sialolithiasis in this case.

Table 3.1. Classification of salivary gland inflammation/infection.

Bacterial infections Acute bacterial parotitis Chronic bacterial parotitis Chronic recurrent juvenile parotitis Acute suppurative submandibular sialadenitis Chronic recurrent submandibular sialadenitis Acute allergic sialadenitis Viral infections Mumps HIV/AIDS Cytomegalovirus Fungal infections Mycobacterial infections Tuberculosis Atypical mycobacteria Parasitic infections Autoimmune‐related inflammation Systemic lupus erythematosus Sarcoidosis Sjögren syndrome

Table 3.2. Risk factors associated with salivary gland inflammation/infection.

Modifiable risk factors Decreased intravascular volume Decreased input (dehydration/prerenal azotemia) Increased output (chronic vomiting/diarrhea) Recent surgery and anesthesia Malnutrition Medications Antihistamines Diuretics Tricyclic antidepressants Phenothiazines Antihypertensives Barbiturates Anti‐sialogogues Anticholinergics Chemotherapeutic agents Sialolithiasis Oral infection Non‐modifiable risk factors Advanced age Relatively non‐modifiable risk factors Radiation therapy where cytoprotective agents were not administered Renal failure Hepatic failure Congestive heart failure HIV/AIDS Diabetes mellitus Anorexia nervosa/bulimia Cystic fibrosis Cushing disease