Adnexal necrobiotic xanthogranuloma presenting as a "kissing" eyelid lesion

Necrobiotic xanthogranuloma (NBX; also termed NXG) is a rare non‑Langerhans cell histiocytosis within the adult orbital xanthogranulomatous disease spectrum. It typically presents with uni‑ or bilateral periocular yellow‑brown infiltrates and can mimic xanthelasma and other inflammatory lesions, with possible systemic associations including paraproteinemia and hematologic malignancy. A 50‑year‑old man presented with an uncommon phenotype limited to the ipsilateral upper and lower eyelids, forming a "kissing" lesion across the lid margin. Three prior debulking procedures performed elsewhere without histopathology resulted in recurrence. A shave biopsy demonstrated foamy histiocytes, multinucleated giant cells, lymphocytes, and necrobiosis, consistent with NBX. Systemic evaluation revealed no paraproteinemia, amyloidosis, IgG4‑related disease, immunodeficiency, or hematologic malignancy. Five intra‑/perilesional corticosteroid injections (triamcinolone; upper lid 0.3 mL [12 mg], lower lid 0.1 mL [4 mg]; 3-9‑month intervals) produced a limited response. Lesions remain stable 2.5 years after the last injection. NBX can rarely present as an isolated "kissing" eyelid lesion. Early histopathologic confirmation helps avoid repeated procedures and triggers appropriate systemic work‑up and longitudinal surveillance.