Reactive soft tissue enlargements are caused by injury, such as infections, physical trauma, chemical trauma, or allergic reactions. Reactive soft tissue enlargements usually have a rapid onset (short duration) and may increase and decrease (fluctuate) in size and usually eventually regress. Reactive enlargements are often, but not always, tender or painful and usually have a more rapid growth rate (measured in hours to weeks) than tumors. Sometimes patients with reactive enlargements will be able to report the source of injury. Sometimes reactive lesions are associated with tender lymph nodes and systemic manifestations, such as fever and malaise. Once it is decided that a soft tissue enlargement is reactive, the next step is to determine what the lesion is reacting to, such as bacterial, viral, or fungal infections or chemical or physical injury.
Some examples of reactive soft tissue enlargements:
- Mucocele (salivary extravasation phenomenon)
- Necrotizing sialometaplasia
- Periodontal abscess
- Radicular (periapical) abscess
- Fibrous hyperplasia
- Inflammatory papillary hyperplasia
Salivary extravasation phenomenon, usually called a "mucocele" occurs when a salivary gland duct is ruptured and mucus forms a pool in the surrounding connective tissue. It most commonly occurs in locations that are easily traumatized, such as the lower lip. Clinical features include a well localized, compressible or fluctuant soft tissue enlargement. The patient may report that the lesion increases and decreases (fluctuates) in size. The surface of the lesion may be blue to purple or normal in color. Sometimes these lesions resolve spontaneously. Persistent lesions should be excised to minimize recurrence. Lesions must be examined microscopically to exclude salivary gland tumors.
Inflammatory papillary hyperplasia represents an overgrowth of epithelial and fibrous connective tissue, usually as a response to chronic irritation from a denture. The lesion occurs on the hard palate or mandibular alveolar mucosa underneath a denture. The surface of the lesion is bumpy, nodular, or velvety, and often erythematous. The patient may complain of pain or burning in association with the lesion, or the lesion may be asymptomatic. Lesions often have concomitant overgrowth of candidal organisms. The patient should remove the denture as much as possible, and the lesion should be reevaluated. If the papillary overgrowth is minimal, the lesion does not need to be removed. More extensive lesions should be excised. The denture should be remade and the patient educated about removing the denture at night and cleaning the denture. If candidosis is present it should be treated with a topical antifungal ointment or cream applied to the inner surface of the denture.
Inflammatory papillary hyperplasia