title: Infectious mononucleosis and acute lymphoblastic leukemia--hand mirror cells: a qualitative and quantitative ultrastructural study.
abstract: The hand mirror cell (HMC) in infectious mononucleosis (IM) is a T cell which appears at the time of improvement and apparently has an important role in immune surveillance. Fifty electron micrographs of HMC from an unusual untreated patient with ALL-HMC variant were compared to 50 electron micrographs of HMC from five patients beginning to recover from IM. Quantitative differences between the IM-HMC and ALL-HMC were observed in multivariate analysis of variance (p < 0.001), nuclear perimeter (p < 0.0001), nuclear length (p < 0.0001), cytoplasmic length (p < 0.0001), total cell area (p < 0.0001), cytoplasmic area (p < 0.0001) and nuclear cytoplasmic ratio (p < 0.004), and numbers of mitochondria (p < 0.001). The qualitative differences included greater nuclear irregularity in the IM-HMC, and prominent nucleolonema in some of the ALL-HMC. In addition, the IM-HMC showed more polyribosomes, parallel tubular arrays and microtubules, but much less glycogen. Since the IM-HMC apparently enter effectively into immune surveillance, and some cases of ALL have HMC, the ultrastructural similarities and differences above contribute to a better understanding of the importance of this unique cell configuration in benign and malignant disorders.
mesh_terms: D014644:Genetic Variation; D006801:Humans; D007244:Infectious Mononucleosis / Q000276:immunology*; D007945:Leukemia, Lymphoid / Q000276:immunology*; D008854:Microscopy, Electron; D013601:T-Lymphocytes / Q000145:classification / Q000473:pathology / Q000648:ultrastructure*