Granular common acute lymphoblastic leukaemia in adults: A morphological study

Abstract

2 cases of acute lymphoblastic leukaemia characterised by the presence of cytoplasmic inclusions morphologically similar to azurophil granules are described. Azurophil granulation of blasts is one of the cardinal features which differentiate acute myeloid from acute lymphoblastic leukaemia. Although such granulation of lymphoblasts has caused diagnostic confusion in the past, we found that the granules could be distinguished from myeloid azurophil granules both morphologically and by their characteristic cytochemical staining reactions. They were negative for peroxidase/sudan black and chloroacetate esterase, but gave coarse scattered granular positivity for both acid phosphatase and alpha‐naphthyl acetate esterase. Both the electron microscopic appearance of the granules and their cytochemical staining reactions suggested that they were lysosomes. Granular ALL does not appear to be associated with any morphological subtype or karyotype; but is strongly associated with the common ALL phenotype. Its prognostic significance remains uncertain. It occurs more frequently than the small number of previous reports might suggest and, given the potential for misdiagnosis, should be more widely recognised.

Case report of granular acute lymphoblastic leukemia and review of the literature

“…However, on rare occasions, these intracytoplasmic inclusions may be found in ALL blasts, termed granular ALL, that defy conventional teaching and diagnostic pathways. 1 Although uncommon, granular ALL may be found at a higher incidence in pediatric patients and may be associated with a worse prognosis in this cohort. 2 We review the case history and pathological findings in an adult patient with granular ALL and discuss the impact of granules on clinical outcomes in these ALL patients through a review of the literature.…”

“…The presence of azurophilic granules in the cytoplasm is one of the key distinguishing features of acute myeloid leukemia (AML) which differentiates it from acute lymphoblastic leukemia (ALL). However, on rare occasions, these intracytoplasmic inclusions may be found in ALL blasts, termed granular ALL, that defy conventional teaching and diagnostic pathways . Although uncommon, granular ALL may be found at a higher incidence in pediatric patients and may be associated with a worse prognosis in this cohort .…”

B lymphoblastic leukemia with granules mimicking acute myeloid leukemia in a 4 years female child

“…The presence of azurophilic granules in the cytoplasm is one of the key distinguishing features of AML which differentiates it from ALL. However, on rare occasions, these intracytoplasmic inclusions may be found in ALL blasts, termed granular ALL that defy conventional teaching and diagnostic pathways [1] . We review the case history and pathological findings in a 4 years child with granular ALL.…”