Kuttner's Tumour: A Case Series and Narrative Review on Diagnosis, Management, and Outcomes.

: Kuttner's tumour refers to chronic sclerosing sialadenitis commonly affecting the submandibular gland. It clinically mimics submandibular gland neoplasms and has a possible association with IgG4-related disease. The literature on standardised diagnostic and management pathways is limited. This paper presents a case series and narrative literature review to support a proposed diagnostic and management approach for Kuttner's tumour. : Twelve cases of patients with a Kuttner's tumour aged between 55 and 87, identified from 2018 to 2025 through hospital records, were reviewed. All patients underwent ultrasound assessment using standardised diagnostic criteria and were followed up clinically and radiologically every six months. In parallel, we performed a narrative review of studies published between 2005 and 2025, identifying nine relevant articles to contextualise our findings. : Our 12-patient case series highlights the potential for Kuttner's tumour to progress to bilateral involvement and IgG4-related disease. Most cases resolved spontaneously with ultrasound-led monitoring. One progressed to IgG4-RD and responded to glucocorticoids. Our findings support the selective use of invasive tests, baseline serum IgG4 testing, and a six-monthly follow-up strategy. Despite similarities within the existing literature, international variation highlights the need for standardised diagnostic and management protocols. : We recommend a conservative, structured approach to managing Kuttner's tumour, with six-monthly clinical and radiological follow-ups. Based on one case progressing to multi-organ IgG4-related disease, we now recommend routinely measuring serum IgG4 concentrations at diagnosis. The role of magnetic resonance imaging, fine-needle aspiration cytology, and biopsy should be considered on a case-by-case basis. Further research is needed to validate this approach and assess long-term outcomes.