Castleman disease arising from the pleura: a case report and literature review.

BACKGROUND: Castleman disease (CD) is a rare lymphoproliferative disorder that commonly involves the abdomen, head and neck, and mediastinum. Primary involvement of the pleura is rare and prone to misdiagnosis. CASE PRESENTATION: We report the case of an asymptomatic 58-year-old male presenting with an incidental left pleural mass detected during a physical examination. While imaging studies initially suggested a solitary fibrous tumor or vascular neoplasm, definitive diagnosis of pleural hyaline vascular unicentric Castleman disease (UCD) was confirmed via pathological and immunohistochemical evaluation following surgical resection. The patient exhibited a favorable recovery after the surgical intervention. CONCLUSION: Based on this case and literature review, the disease predominantly affects young to middle-aged individuals and seems to have no significant gender predilection. About half of patients with pleural UCD present with clinical symptoms, a relatively high proportion. Imaging and laboratory tests have limited diagnostic value for this condition, definitive diagnosis relies on histopathological examination, and surgical resection typically leads to a favorable prognosis. It is recommended to consider rare diseases such as CD in the differential diagnosis of pleural masses.