Heterogeneity of immunologic markers and surface morphology in childhood lymphoblastic lymphoma

The neoplastic cells from seven 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 nonimmune rosette formation with sheep red blood cells (E). In one patient the cells exclusively bound E, suggesting a T-lymphocytic origin. In two patients the cells bound EAC, but demonstrated no other B-lymphocytic markers. In two patients no markers were detected, and in two 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 four patients the cells were predominately smooth, whereas in two 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 four cases is a feature not previously reported in this disease and should be investigated in other presumed T-cell malignancies.