Combined assessment of tumour cell nest size and desmoplastic reaction as an excellent prognostic predictor in oesophageal squamous cell carcinoma Aims: Tumour budding (TB) activity, cell nest size (CNS), and desmoplastic reaction (DR) have been confirmed to be significantly correlated with prognosis in oesophageal squamous cell cancer (ESCC) recently. However, there are limited data on the prognostic significance of combined assessment of cellular dissociation and tumour stroma in ESCC. Methods: In all, 265 cases with resected ESCCs diagnosed between January 2018 and August 2019 were retrospectively reviewed. All slides were reviewed for assessing TB, CNS, and DR. The Cellular Dissociation Grading and our Combined CNS and DR (CNS/DR) Grading systems were adopted to re-grade ESCCs. Results: High TB activity, small CNS, and immature DR had a strong association with shorter overall survival (OS) and progression-free survival (PFS) (P < 0.001, respectively) in ESCC. Combined assessment of CNS and DR in a 4-tiered grading system displayed a prognostic excellence for survival (P < 0.001), and outperformed the Cellular Dissociation Grading for both OS (area under the curve [AUC], 0.728 versus 0.644, P = 0.043) and PFS (AUC, 0.763 versus 0.667, P = 0.018) by receiver operator characteristic curves. Also, Combined CNS/DR Grading showed superiority in recognizing a G4 subgroup with the worst outcome in our cohort, to whom the most urgent attention needs to be called. Conclusions: This is the first study to propose a novel Combined Grading system based on CNS and DR in ESCC, which has been demonstrated to be relatively superior to Cellular Dissociation Grading in predicting prognosis. The findings shed new light on the histopathological grading of ESCC and facilitates identifying biologically aggressive ESCCs.