Unicentric Castleman Disease Involving the Submandibular Gland: A Case Report.

This report describes a rare case of unicentric Castleman disease (UCD) involving the submandibular gland and lymph nodes. A 56-year-old man presented with an asymptomatic, slowly growing left submandibular mass. Imaging revealed well-defined heterogeneous structures with prominent vascularity. Excisional biopsy of the gland and adjacent lymph nodes was performed. Histopathological examination showed features characteristic of the hyaline-vascular variant of Castleman disease, including atrophic germinal centers with concentric "onion-skin" layering and prominent vascularity, confirmed by immunohistochemistry. No systemic involvement was found. These findings confirmed the unicentric subtype. After complete surgical excision and 3 years of follow-up, the patient remained disease-free. This report underscores that UCD can occur in the submandibular region, should be included in the differential diagnosis of submandibular masses, diagnosed by characteristic imaging (well-defined heterogeneous structures with prominent vascularity) and histopathology (hyaline-vascular variant), and cured by complete surgical resection.