HETEROGENEITY OF IMMUNOLOGICAL MARKERS AND SURFACE MORPHOLOGY IN CHILDHOOD LYMPHOBLASTIC LYMPHOMA

Abstract

The neoplastic cells from 7 patients with childhood lymphoblastic lymphoma were studied for cell surface markers and surface morphology in the scanning electron microscope (SEM). The cells were studied for surface immunoglobulin (Slg), complement receptors (EAC), receptors for cytophilic antibody (IgGEA) and non-immune rosette formation with sheep red blood cells (E). In 1 patient the cells exclusively bound E, suggesting a T [thymus derived] lymphocytic origin. In 2 patients the cells bound EAC, but demonstrated no other B [bone marrow derived] markers. In 2 patients no markers were detected, and in 2 patients receptors for both E and EAC were demonstrated. Additional studies in one of these patients permitted simultaneous demonstration of both markers on the same neoplastic cells. The neoplastic cells were also examined by SEM after fixation and critical point dehydration. No consistent surface morphology was observed. In 4 patients the cells were predominately smooth but in 2 patients variable numbers of surface microvilli were present. A correlation of the surface features with membrane markers could not be established. A comparison of the surface markers with clinical and cytologic features revealed clinical homogeneity in spite of the heterogeneous immunologic markers. This heterogeneity was most likely a reflection of neoplastic alteration and disordered differentiation of the cells. The observation of complement receptors on the cells of 4 cases was a feature not previously reported in this disease and should be investigated in other presumed T-cell malignancies.