Introduction
Chronic sclerosing sialadenitis, or Kuttner's tumor, is a chronic (long-lasting) inflammatory lesion or glandular swelling characterized within the salivary glands. Though technically it is non-cancerous or is a non-malignant condition, it is referred to colloquially as a tumor because clinically, it manifests as a firm swelling of the salivary gland that would make it challenging to differentiate it from a neoplastic (abnormal growth of tissue) or malignant (cancerous) lesion associated swelling of the same. Kuttner’s tumor is named after the German oral and maxillofacial surgeon Herman Kuttner. The diagnosis of this condition is benign and is only confirmed after the lesion is surgically excised (removed).
The condition can only be confirmed through a microscopic diagnosis. Dentists and oral surgeons can only suggest possible diagnoses until the histological findings after removal of the tissue confirm reactive follicles (small clusters of cells responding to infection) and lymphoplasmacytic infiltration (immune cells like lymphocytes and plasma cells in the tissue).
What Are the Clinical Features and Etiology of Kuttners Tumor?
Salivary gland cancers affect nearly three to five percent of the global population, accounting for its proportion of reported head and neck cancers. The lesions in Kuttner's tumor or chronic sclerosing sialadenitis are similar to a neoplastic or malignant lesion - mainly hard, indurated, and swollen lesions bilaterally in the neck (at the region of submandibular glands or glands located beneath the jaw) as clinical features. The patients complain not just of swelling but also of severe pain at times, which can cause orofacial (mouth and face) discomfort and masticatory (chewing) troubles. However, in the case of Kuttner's tumor, the lesions are not only non-malignant but simply composed of reactive cells histologically, making the clinical diagnosis specifically difficult.
Particularly, Kuttner's tumor affects the submandibular glands (though the occurrences are also reported in the parotid gland (a major salivary gland located in front of the ear) and sublingual (under the tongue) salivary gland). Its clinical occurrence as glandular swelling in the neck may be bilateral (both sides) most of the time. Because of the firm and hard consistency, glandular swelling can be mistaken for a tumor clinically. This condition is more prevalent in males than females and usually affects the middle-aged or elderly population.
Though the exact mechanism of its occurrence may remain elusive, the presence of certain factors like abnormal immune response and infiltration (especially if autoimmune, that is, conditions where the immune system attacks the body’s own tissues origins, are associated with an increased serum Ig4 secretion) and sialoliths or salivary stone formation (sialolithiasis) is attributable to the development of Kuttner's tumor or chronic sclerosing sialadenitis. At times when a sialolith cannot be seen in this condition, and there is no identifiable autoimmune cause, the causative would be the retention or over-accumulation of the salivary gland ductal secretions. The trapped salivary secretions can be the cause of potentially chronic inflammatory lesions seen in this condition.
How Is Kuttners Tumor Diagnosed?
Though various diagnostic methods for observing and researching the cells of Kuttner's tumor exist, FNAC (fine needle aspiration cytology, a procedure that uses a thin needle to extract tissue for examination) is recommendable for carrying out a thorough or detailed investigation into the cell morphology. Other accessory diagnostic modalities like ultrasonogram (an imaging technique using sound waves) and MRI (magnetic resonance imaging), though useful and non-invasive, may still prove inconclusive evidentially for establishing an accurate diagnosis. However, in MRI- the cell morphology obtained can be accurately used to distinguish it from the pattern of malignant cells that rule out or help differentiate their condition from potential salivary gland neoplasms of head and neck tumors.
Diagnosis is made by the pathologist upon histopathologic examination of the excised lesion. Fine needle aspiration cytology is a recommended technique to observe the lymphoplasmacytic infiltration (an increase in immune cells, including lymphocytes and plasma cells) distinctive of this condition. The histopathologic features observed are periductal fibrosis (thickening of the tissue around the ducts) and lymphoplasmacytic cell infiltration around the glandular tissues thickened or congealed glandular secretions (the salivary glands have a normal lobular architecture that remains unaffected in this condition), reactive follicles are seen within the gland space, progressive atrophy (wasting away of tissue) accompanied by loss of acini (saliva secreting cells), interlobular sclerosis (thickening of the tissue between gland lobes) along with periductal sclerosis (fibrosis around the ducts) meaning the connective tissue cells replace the gland tissue.
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Immunochemistry: Upon examining cells in this investigative modality, CD-8 positive cytotoxic cells (immune cells that kill other cells) are predominantly observed with an abundance of IgG 4 positive plasma cells (a type of antibody).
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Molecular Investigation: Upon molecular studies, researchers have found the presence of a well-established T cell receptor rearrangement (T cells arranged in a polyclonal (multiple diverse T cell clones), oligoclonal (few T cell clones dominate), or monoclonal (single T cell clone dominates) fashion) within the lesion.
How Is Kuttners Tumor Treated?
The standard surgical procedure for excision of the lesion or nodular mass of Kuttner's tumor is the sialoadenectomy (surgical removal of the salivary gland) procedure.
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Submandibular Sialoadenectomy: In specific, as most cases involve the submandibular gland, submandibular sialoadenectomy is preferred. This is a common head and neck surgical procedure to resolve or excise benign and malignant tumors that may or may not involve the condition of sialolithiasis or sialolith or salivary stone formation. The maxillofacial surgeon, after giving an incision, performs both ligation (ties off) and transection (cuts) of the facial artery and vein (blood vessels supplying the face). The wound drainage is done either by suction or non-suction. The modified sialoadenectomy procedure is an advanced technique for avoiding wound drainage and preservation of the facial artery and vein. In the modified technique, the main difference is a minimal incision is given conservatively.
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Corticosteroid Therapy: This is the first-line modality used if the lesion has a scope of being controlled and shrunk non-surgically. It is indicated for IgG4-related disease (a condition involving abnormal immune system response). This therapy is instituted with a high daily dosage of Prednisone as advised by the surgeon - varying from 30 to 60 mg (milligrams) for a three to six-month period. This therapy benefits younger patients as it is an alternative to surgical therapy or sialoadenectomy. The corticosteroid acts by shrinking the size of the lesion and may be accompanied by the use of immunosuppressive agents (medications that reduce immune system activity) as advised by the physician in controlling refractory or recurrent diseases of Kuttner's tumor.
Conclusion:
Kuttner's tumor, through a benign and non-tumorous condition, poses a constant problem of orofacial and glandular swelling that can be resolved only after intervention by the maxillofacial surgeon and physician. Early diagnosis, correct diagnostic intervention for differentiation from malignant tumors, and finally, surgical or non-surgical treatment instituted by the surgeon are beneficial to prevent both the impact and long-term recurrence of this condition.
