Histological and immunohistochemical features of uterine T-cell lymphoblastic lymphoma. A diffuse proliferation of round blue cells infiltrating endometrial glands and stroma and dissecting the muscle fiber is observed (A). Cells exhibit a blastic appearance (B). They are positive for TdT (C) and CD2 (D). [A-B: haematoxylin and eosin (H & E), C: TdT stain, D: CD2 stain; A, C-D: original magnification (O.M.), 20×, B: O.M., 40×].