Pseudo-Chediak-Higashi Anomaly in Acute Myeloid Leukaemia

Abstract

2 cases of acute myeloid leukaemia with inclusion bodies are presented. The inclusions were found mainly in the blast cells but could also be encountered in lymphocytes and plasma cells. Cytochemical and ultrastructural studies showed a great resemblance of these inclusions to the ones found in Chediak-Higashi anomaly, i.e., high acid phosphatase activity, varying in size of inclusions from clusters of small granules to huge inclusion, sometimes found in vacuoles, featuring fusion of lysosomes.

Acute Promyelocytic Leukemia With Pseudo-Chediak-Higashi Anomaly: A Case Report and Review of the Literature

“…The inclusions were described as large but variable in size, from 1 μ to giant inclusions of 7 μm, which simulated phagocytosed red blood cells. 4,5,11 The inclusions in all these cases with one exception were present only in the leukemic cells. 4 These giant granules were described in a variable but usually small proportion up to 10% of cells.…”

“…Rarely have large inclusions been described. [1][2][3][4][5][6][7][8][9][10][11] In 1974, Van Slyck and Rebuck 1 described the pseudo-Chediak-Hegashi anomaly (PSCA), in which granules similar to those seen in Chediak-Higashi syndrome were identified in the leukemic cells from two patients with acute myelomonocytic leukemia (AMLM 4 ). The granules were described as pink and azurophilic.…”

“…Since then, 15 cases of adult leukemia with the PSCA have been described. [2][3][4][5][6][7][8][9][10][11] There were four APL, one AML highly suggestive of APL, three AMLM 4 , one chronic myelocytic leukemia (CML), and six cases of AML which were not further subtyped. In addition, the majority of cases in a series of APL 12 displayed oval or elliptical inclusions occupying one-third to one-half of the cytoplasm.…”

“…Occasionally, both azurophilic and pink granules have been seen in the same case. 1,4 In the majority of cases, the inclusions were described as round and homogenous. However, irregular granules have been described, and some were reported to be present in vacuoles.…”

“…However, irregular granules have been described, and some were reported to be present in vacuoles. 4,9,11 Auer rods were also present in many cases, in addition to the large granules, [3][4][5][6][7] while in others, only the granules were present.…”