Objectives: Large granular lymphocytic leukemia (LGLL) represents a rare neoplasm of mature T cells or natural killer (NK) cells, with an indolent clinical course. Diagnosing LGLL can be challenging because of overlapping features with reactive processes and other mimickers.
Methods: By presenting 2 challenging cases, we elucidate the differentiation of LGLL from its mimics and highlight potential diagnostic pitfalls.