Improvement in the diagnosis and treatment of T2 gallbladder carcinoma is pivotal to improvement in the overall prognosis for this disease.

Since the American Joint Committee on Cancer (AJCC) subdivided the T2 stage of gallbladder carcinoma (GBC) into T2a and T2b, the diagnosis and treatment of those stages have been a subject of heated discussion and controversy. T2 is a stage of GBC that might be treatable. Based on the extent of lymph node metastasis and distant metastasis, T2 GBC can be classified into various pathological stages such as IIA, IIB, IIIB, and IVB, leading to controversy in clinical settings. This review aims to discuss the effectiveness of and controversies concerning S4b+5 resection, the acceptable extent of lymph node dissection, the timing for treatment of incidental gallbladder cancer, and adjuvant therapy. This review also aims to suggest directions for and recommendations regarding clinical research in the future.