Goeun Lee1, You-Na Sung1, Sung Joo Kim1, Jae Hoon Lee2, Ki-Byung Song2, Dae Wook Hwang2, Jihun Kim1, Sang Soo Lee3, Song Cheol Kim2, Seung-Mo Hong4. 1. Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea. 2. Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea. 3. Department of Gastroenterology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea. 4. Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea. Electronic address: smhong28@gmail.com.
Abstract
BACKGROUND: Solid pseudopapillary neoplasms (SPNs) of the pancreas have low malignant potential. However, malignant SPNs are not fully understood. METHODS: To evaluate risk factors affecting malignant potential, the clinicopathologic features of 375 surgically resected SPNs were compared. RESULTS: Fifty (13.3%) had malignant histologic features. Twenty-seven and 22 had perineural and lymphovascular invasions, respectively. Adjacent organ invasion was noted in 9 cases. Recurrence occurred in 8 cases. The median recurrence time after surgical resection was 67 months and was associated with a higher pT category (P = 0.001), lymphovascular invasion (P < 0.001), and synchronous metastasis (P < 0.001). SPN patients with malignant histologic features had worse recurrence-free survival (RFS; 10-year survival rate, 73.2%) than those without malignant histologic features (96.3%; P = 0.01). Patients with a higher pT category (P = 0.04), synchronous metastasis (P < 0.01), and lymphovascular invasion (P < 0.01) had worse RFS. Lymphovascular invasion (P = 0.042) and a higher T category (P = 0.002) were poor prognostic factors for recurrence. CONCLUSION: Lymphovascular invasion and a higher T category were worse prognostic factors for recurrence in SPN patients with malignant histologic features. For SPN patients with malignant histologic features, a longer follow-up may be required.
BACKGROUND: Solid pseudopapillary neoplasms (SPNs) of the pancreas have low malignant potential. However, malignant SPNs are not fully understood. METHODS: To evaluate risk factors affecting malignant potential, the clinicopathologic features of 375 surgically resected SPNs were compared. RESULTS: Fifty (13.3%) had malignant histologic features. Twenty-seven and 22 had perineural and lymphovascular invasions, respectively. Adjacent organ invasion was noted in 9 cases. Recurrence occurred in 8 cases. The median recurrence time after surgical resection was 67 months and was associated with a higher pT category (P = 0.001), lymphovascular invasion (P < 0.001), and synchronous metastasis (P < 0.001). SPN patients with malignant histologic features had worse recurrence-free survival (RFS; 10-year survival rate, 73.2%) than those without malignant histologic features (96.3%; P = 0.01). Patients with a higher pT category (P = 0.04), synchronous metastasis (P < 0.01), and lymphovascular invasion (P < 0.01) had worse RFS. Lymphovascular invasion (P = 0.042) and a higher T category (P = 0.002) were poor prognostic factors for recurrence. CONCLUSION: Lymphovascular invasion and a higher T category were worse prognostic factors for recurrence in SPN patients with malignant histologic features. For SPN patients with malignant histologic features, a longer follow-up may be required.