Morphologic study of virus-like particles in a case of acute leukemia

Virus-like particles in leukaemia

Hitherto intracytoplasmic virus-like particles have not been observed simultaneously in nucleus and cytoplasm in human lymphoblasts. We analysed 20 cases of lymphoblastic leukaemia in children and found some virus-like particles in cytoplasm (12 cases) and both in nucleus and cytoplasm (4 cases).

Tubular complexes of endoplasmic reticulum in lymphoblastic lymphoma: case report

Distinctive intracytoplasmic tubular complexes have been identified occasionally by electron microscopy in a wide variety of hematologic and nonhematologic disorders. The mechanism of induction and significance of these tubular complexes are unknown. Tubular complexes were identified in the majority of bone marrow lymphoma-leukemia cells in a patient with documented lymphoblastic lymphoma in lymph node. These complexes varied in size but in general ranged from 800--1500 nm, and consisted of masses of nonparallel, twisted, smooth, 40-nm tubules. Continuity with adjacent endoplasmic reticulum was evident in some of the complexes. Cytochemical characteristics of the malignant cells included strong, focal, paranuclear acid phosphatase reactivity and strong, stippled nuclear terminal deoxynucleotidyl transferase positivity. Flow cytometric analysis showed a DNA-RNA content pattern consistent with acute lymphoblastic leukemia and typical of T-cell lymphoma. This represents the first report of such tubular complexes in a presumed T-cell malignancy.

Tubular complexes of endoplasmic reticulum in myeloblasts of acute myelogenous leukemia

The leukemic cells from 9 patients with acute myelogenous leukemia were studied by light microscopy, cytochemistry, and electron microscopy. In Wright-Giemsa-stained blood and bone marrow preparations, from less than 1% to greater than 95% of the leukemic cells from the 9 patients contained inclusions that measured one-third to one-half the diameter of the cell. In 4 patients the inclusions appeared to be associated with intense focal myeloperoxidase activity. Ultrastructural studies demonstrated that the inclusions were complexes of smooth, membranous, anastomosing 50-nm tubules and 80-nm particles. These complexes were surrounded by bundles of microfilaments and numerous mitochondria. The tubular complexes resembled the tubuloreticular structures that have been reported in lymphoreticular and endothelial cells from patients with autoimmune and viral diseases.