[Clinicopathologic features and prognosis of retroperitoneal unicentric Castleman disease: report of 38 patients].

Objective: To explore the clinical and pathological characteristics and prognosis of retroperitoneal unicentric Castleman disease (UCD). Methods: This study employed a retrospective observational research design. The inclusion criteria were: (1) postoperative pathological confirmation of Castleman disease; (2) patients underwent surgical treatment; (3) preoperative imaging diagnosis of a retroperitoneal unicentric lesion; (4) complete clinicopath- ological data. Exclusion criteria: (1) received preoperative antitumor therapy; (2) had a history of other malignancies within the past 5 years. According to these criteria, clinicopathological and follow-up data of 38 patients with retroperitoneal UCD treated at Tianjin Medical University Cancer Hospital from January 2015 to August 2024 were collected. The clinicopathological characteristics and prognosis were analyzed. Results: Among the 38 patients with retroperitoneal UCD, there were 12 males and 26 females. The mean age was (42.8±15.4) years (range, 18-70 years), and the mean maximum tumor diameter was (5.8±2.3) cm. The disease had no specific clinical manifestations, and 28 cases (73.7%) were detected during physical examination. Of the 38 patients, 35 (92.1%) underwent radical resection, while 3 (7.9%) received intracapsular piecemeal resection due to large, invasive tumor growth. Postoperative pathology revealed that 32 cases (84.2%) were of the hyaline vascular type, and 3 cases (7.9%) each were of the plasma cell type and mixed type, respectively. The median follow-up duration was 32.4 months (range, 3-78 months). Eight patients were lost to follow-up, 6 died of other diseases, and the remaining 24 patients had no recurrence during postoperative follow-up (including 3 patients who underwent piecemeal resection, with no tumor progression). Competing risk model analysis showed that the 5-year tumor-specific survival rate of patients with retroperitoneal UCD after surgical treatment was 100%. In the sensitivity analysis, the 5-year survival rate under the worst-case scenario was 75.0%. Conclusions: Retroperitoneal unicentric Castleman disease has a low incidence and lacks specific clinical manifestations. Surgical treatment is the main therapeutic approach, and patients have a favorable prognosis.