Irene Chen1, Dongwei Zhang1, Moises Velez1, Sierra Kovar1, Xiaoyan Liao2. 1. Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY, USA. 2. Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY, USA. Electronic address: Xiaoyan_liao@urmc.rochester.edu.
Abstract
OBJECTIVES: To characterize the clinicopathologic and immunohistochemical features of poorly differentiated neuroendocrine carcinomas (NEC) in the gastrointestinal tract. DESIGN: A total of 43 cases were identified and reassessed based on modern classification. RESULTS: The cohort (27M, 16F; median age: 66 years) included 16 (37%) large cell NEC, 12 (28%) small cell NEC, 5 (12%) NEC not otherwise specified, and 10 (23%) mixed adenoneuroendocrine carcinomas. Tumor predominantly involved the colon (n = 14, 33%), rectum (n = 13, 30%), and esophagus (n = 9, 21%). Immunohistochemically, INSM1 was the most sensitive marker for neuroendocrine differentiation (28/28, 100%), followed by synaptophysin (40/43, 93%), CD56 (22/35, 63%), and chromogranin (18/40, 45%). SATB2, CDX2, CK20, CK7, abnormal p53, and PD-L1 was positive in 21/26 (81%), 26/37 (70%), 11/35 (31%), 10/35 (29%), 19/24 (79%), and 12/23 (52%) cases, respectively. Three of 25 (11%) were mismatch repair protein deficient. Of 21 resected tumors, 19 (90%) were ≥ pT3 and 13 (62%) had nodal metastasis. Twenty-eight (65%) had distant metastasis. The 5-year survival rate was 21%. The prognosis was stage dependent (p < 0.05), but not associated with tumor type, location, or specific immunomarkers. CONCLUSION: Gastrointestinal NECs are aggressive neoplasms. INSM1, synaptophysin, and SATB2 are sensitive markers, although not site or tumor type specific.
OBJECTIVES: To characterize the clinicopathologic and immunohistochemical features of poorly differentiated neuroendocrine carcinomas (NEC) in the gastrointestinal tract. DESIGN: A total of 43 cases were identified and reassessed based on modern classification. RESULTS: The cohort (27M, 16F; median age: 66 years) included 16 (37%) large cell NEC, 12 (28%) small cell NEC, 5 (12%) NEC not otherwise specified, and 10 (23%) mixed adenoneuroendocrine carcinomas. Tumor predominantly involved the colon (n = 14, 33%), rectum (n = 13, 30%), and esophagus (n = 9, 21%). Immunohistochemically, INSM1 was the most sensitive marker for neuroendocrine differentiation (28/28, 100%), followed by synaptophysin (40/43, 93%), CD56 (22/35, 63%), and chromogranin (18/40, 45%). SATB2, CDX2, CK20, CK7, abnormal p53, and PD-L1 was positive in 21/26 (81%), 26/37 (70%), 11/35 (31%), 10/35 (29%), 19/24 (79%), and 12/23 (52%) cases, respectively. Three of 25 (11%) were mismatch repair protein deficient. Of 21 resected tumors, 19 (90%) were ≥ pT3 and 13 (62%) had nodal metastasis. Twenty-eight (65%) had distant metastasis. The 5-year survival rate was 21%. The prognosis was stage dependent (p < 0.05), but not associated with tumor type, location, or specific immunomarkers. CONCLUSION: Gastrointestinal NECs are aggressive neoplasms. INSM1, synaptophysin, and SATB2 are sensitive markers, although not site or tumor type specific.