Kimura Disease in an Adolescent With Type 1 Diabetes Mellitus: A Rare Co-occurrence of T Helper 2-Driven Eosinophilic Lymphadenopathy and Autoimmune Endocrinopathy.

Kimura disease (KD) is a rare, chronic T helper 2 (Th2)-driven inflammatory disorder characterized by painless head-and-neck lymphadenopathy or subcutaneous masses, peripheral and tissue eosinophilia, and markedly elevated serum immunoglobulin E (IgE). It predominantly affects young men of Asian descent. Although KD is regarded as an allergic or immune-dysregulatory rather than a classically autoimmune condition, it has been described in association with nephrotic syndrome, suggesting an underlying systemic immunologic disturbance. Its co-occurrence with type 1 diabetes mellitus (T1DM), an archetypal organ-specific autoimmune disease, has not, to our knowledge, been previously reported. A 17-year-old male with T1DM diagnosed at nine years of age presented with a painless, slowly enlarging right submandibular mass of 18-24 months' duration, without fever, night sweats, or weight loss. Examination revealed a firm, non-tender 3 × 3 cm right submandibular swelling. Investigations showed leukocytosis with marked eosinophilia and serum IgE persistently above 5000 IU/mL. Neck computed tomography demonstrated a 4.2 × 2.3 cm inhomogeneously enhancing submandibular mass with ipsilateral cervical lymphadenopathy, considered suspicious for lymphoproliferative disease. An extensive infectious work-up was negative. Additionally, serology revealed a broadly negative autoantibody profile. There was significant IgE-mediated food allergy and chronic rhinosinusitis, on a background of a strong family history of autoimmune disease. Two sequential ultrasound-guided core-needle biopsies were non-diagnostic, showing only reactive lymphoid hyperplasia with focal microabscess and granuloma formation. Excisional lymph node biopsy demonstrated preserved follicular architecture with paracortical eosinophilic infiltration, eosinophilic microabscesses, Charcot-Leyden crystals, and vascular proliferation, without malignancy and with negative Epstein-Barr virus (EBV)-encoded small RNA (EBER) and human herpesvirus 8 (HHV-8) staining, diagnostic of KD. This report describes a classic presentation of KD occurring in an adolescent with established T1DM and a broader personal and familial autoimmune and atopic diathesis. It supports the view that KD may arise within a wider spectrum of immune dysregulation rather than in isolation, and reinforces that excisional biopsy, not needle sampling, is required for timely diagnosis.