Introduction
Chronic sclerosing sialadenitis or Kuttner's tumor is a chronic inflammatory lesion or glandular swelling characterized within the salivary glands. Though technically it is non-cancerous or it is 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 or malignant lesion associated swelling of the same. It was named after the German oral and maxillofacial surgeon Herman Kuttner, and the interesting fact about this condition is that the diagnosis of it being a non-cancerous entity can be made only once the lesion is surgically excised.
The existence of the condition can be confirmed only after histologic diagnosis, and clinically the dental surgeon or the oral and the maxillofacial surgeon can only establish a differential diagnosis till the histological observations (after excision) confirm reactive follicles and lymphoplasmacytic infiltration.
What Are the Clinical Features and Etiology for Kuttner's Tumor?
Salivary gland cancers affect nearly 3 to 5% of the global population accounting for its proportion of reported head and neck cancers. The lesions in the Kuttner's tumor are similar to a neoplastic or malignant lesion - mainly hard, indurated, and swollen lesions bilaterally in the neck (at the region of submandibular salivary glands) as clinical features. The patients complain not just of swelling but also of severe pain at times, which can cause orofacial discomfort and masticatory 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 salivary glands (though its occurrences are also reported in the parotid gland and sublingual salivary gland). Its clinical occurrence as glandular swelling in the neck may be bilateral most of the time. Because of the firm and hard consistency, glandular swelling can be mistaken for a tumor clinically. This condition has more prevalence in males than in females and usually affects the middle-aged or the 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 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. 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 reason for causing potentially chronic inflammatory lesions seen in this condition.
How Is Kuttner's Tumor Diagnosed?
Though various diagnostic methods for observing and researching the cells of Kuttner's tumor exist, FNAC (Fine needle aspiration cytology) is recommendable for carrying out a thorough or detailed investigation into the cell morphology. Other accessory diagnostic modalities like ultrasonogram 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 distinctive of this condition. The histopathologic features observed are: periductal fibrosis 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 accompanied by loss of acini (saliva secreting cells), interlobular sclerosis along with periductal sclerosis meaning the connective tissue cells replace the gland tissue.
Immunochemistry:
Upon the examination of cells in this investigative modality, CD-8 positive cytotoxic cells are predominantly observed with an abundance of IgG 4 positive plasma cells.
Molecular Investigation:
Upon molecular studies, researchers have found the presence of a well-established T cell receptor rearrangement (T cells arranged in a polyclonal, oligoclonal, or monoclonal fashion) within the lesion.
How Is Kuttner's Tumor Treated?
The standard surgical procedure for excision of the lesion or nodular mass of Kuttner's tumor is the sialoadenectomy procedure.
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 involve or not involve the condition of sialolithiasis or sialolith or salivary stone formation. The maxillofacial surgeon, after giving an incision, performs both ligation and transection of the facial artery and vein. 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.
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. This therapy is instituted with a high daily dosage of Prednisone as advised by the surgeon - varying from 30 to 60 mg for a 3 to 6 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 as advised by the physician in controlling refractory or recurrent diseases of the 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.
