MRI Clarifies Recurrent Kimura Disease Behind Unilateral Parotid Swelling
A slowly enlarging, painless parotid mass can look deceptively simple at the bedside and still conceal a rare inflammatory disorder with a long arc of recurrence. In this BMJ case report, an Indian man in his early 40s returned with a 6-month history of progressive swelling over the left parotid region, years after prior surgery for Kimura disease. The presentation was quiet clinically: no fever, no trauma, and no abrupt systemic illness to suggest an infectious or post-traumatic process. Yet the imaging and cytology told a different story.
He had undergone left parotid surgery 7 years earlier, and histopathology at that time had confirmed Kimura disease. The new mass was not a new disease entity so much as a recurrence of the same chronic inflammatory process. Few palpable left cervical lymph nodes were present on examination, fitting the classic head and neck distribution of this eosinophilic disorder. In a condition known for indolent swelling and regional nodal involvement, the absence of pain or constitutional symptoms can delay suspicion unless imaging is pursued early.
Heterogeneous Parotid Signal and Enhancing Cervical Nodes on MRI
MRI provided the first major clue that this was not a simple postoperative change. The left parotid gland was enlarged and showed heterogeneous T2-weighted and FLAIR hyperintensity, with intense post-contrast enhancement. Ipsilateral cervical lymph nodes also enhanced. Those findings pointed toward an active inflammatory lesion rather than a discrete neoplasm or postoperative scar alone.
The imaging pattern matters because Kimura disease often produces infiltrative soft-tissue enlargement with nodal disease, and MRI can help define the extent of involvement before tissue sampling or repeat surgery. Intensely enhancing parotid tissue in the setting of recurrent, painless swelling is a reminder that chronic inflammatory disorders can mimic tumors on first pass. In head and neck practice, radiologic suspicion can shorten the path to diagnosis when the differential includes salivary neoplasm, chronic sialadenitis, lymphoma, and other eosinophil-rich inflammatory conditions.
A single recurrence years after the original operation is enough to change the clinical posture from routine follow-up to renewed diagnostic workup.
Eosinophilia and Fine-Needle Aspiration Confirm the Inflammatory Nature
Fine-needle aspiration cytology settled the question further. The aspirate showed benign lymphoid proliferation with marked eosinophilia, which aligned with recurrent Kimura disease. That cytologic picture fits the immune-driven biology of the disorder, in which prominent eosinophilic infiltration accompanies lymphoid hyperplasia and chronic regional swelling. The case abstract describes the underlying process as likely related to an abnormal immune response, and the pathology here was consistent with that framework.
In practical terms, the diagnosis rested on converging evidence: prior histologic confirmation, recurrent unilateral parotid enlargement, cervical lymphadenopathy, MRI features of inflammatory disease, and eosinophil-rich benign cytology. No single element alone was definitive, but together they made recurrence far more likely than a new structural lesion. For clinicians, the combination of salivary gland swelling and eosinophilia should keep Kimura disease on the short list, especially in patients with a documented prior history of the disorder.
Combined Therapy Produced Marked Clinical Improvement
Treatment used a combined approach with oral prednisolone, cyclosporine, and surgery, leading to significant improvement. In recurrent disease, that multimodal strategy is biologically sensible. Corticosteroids can suppress active inflammation quickly, while cyclosporine targets T-cell mediated immune activity and may help control a process that tends to smolder and return after local therapy alone. Surgery can reduce bulky disease and provide tissue for confirmation, but recurrence remains a known concern when the inflammatory driver persists.
The case does not present a randomized comparison or a quantified recurrence rate, and it should not be read as proof that one regimen is universally superior. What it does show is a realistic bedside sequence: imaging raises suspicion, cytology supports a benign eosinophilic inflammatory process, and combined immunosuppressive and surgical management can control symptomatic recurrent parotid disease. In a chronic disorder like Kimura disease, the goal is not only removal of visible tissue but also suppression of the immune activity that keeps the lesion returning.
Recurrent Salivary Swelling Should Trigger a Wider Differential
This case has particular relevance for head and neck clinicians, radiologists, and pathologists because unilateral parotid swelling often defaults to more common explanations. Benign salivary tumors, chronic inflammatory parotitis, lymphoid lesions, and malignant processes all enter the differential, but recurrent disease after prior histologic diagnosis should immediately raise the possibility of relapse. MRI cannot diagnose Kimura disease on its own, yet it can distinguish an inflammatory pattern from a purely cystic or sharply circumscribed mass and guide the next diagnostic step.
The report also reinforces how easily a rare disorder can remain clinically silent apart from local enlargement. No fever, no trauma, and no acute infectious syndrome were present. Instead, the disease declared itself through anatomy, signal intensity, enhancement, and tissue eosinophilia. In that sense, the imaging pattern was not merely descriptive; it functioned as a bridge between a physical exam finding and the underlying immunopathology.
For patients with prior Kimura disease, especially those who return years later with the same side of the face involved, the threshold for repeat imaging and tissue sampling should be low. Recurrence is not an academic possibility in this setting; it is a practical diagnostic concern that can shape whether clinicians choose observation, immunosuppression, repeat surgery, or a combination of all three.