Expression of erythroid-specific genes in acute megakaryoblastic leukaemia and transient myeloproliferative disorder in Down's syndrome

Summary. Acute megakaryoblastic leukaemia (M7) and transient myeloproliferative disorder in Down's syndrome (TMD) are characterized by rapid growth of abnormal blast cells which express megakaryocytic markers. To clarify properties of the blast cells in M7 and TMD cases, we examined erythroid markers expression in blasts from six cases with M7 and seven cases with TMD in this study. Erythroid-specific mRNAs encoding 7-globin and erythroid 6-aminolevulinate synthase were found to be expressed in blasts from most of these cases, indicating that majorities of the blasts in M7 and TMD cases have erythroid and megakaryocytic phenotypes. We also found that mRNAs encoding GATA-1 and GATA-2 are expressed in all these cases. These results suggest that M7 blasts and TMD blasts correspond to the erythroid/megakaryocytic bipotential progenitor cells.     

Colchicine in the treatment of the cutaneous manifestations of Behçet's disease

Five patients with Behçet's disease were satisfactorily treated with colchicine. Oral aphthosis, erythema nodosum-like lesions and genital erosions improved greatly within a month as did laboratory findings. We believe colchicine to be the first choice in the management of the cutaneous and ocular lesions of Behçet's disease.     

p53 GENE ALTERATIONS AND p53 PROTEIN IN ORAL EPITHELIAL DYSPLASIA AND SQUAMOUS CELL CARCINOMA

To examine the expression of p53 protein and gene alterations in oral epithelial lesions including epithelial dysplasias and primary squamous cell carcinomas, immunohistochemical and temperature gradient gel electrophoresis (TGGE) methods were applied to formalin-fixed and paraffin-embedded tissues. Morphologically normal mucosal epithelium stained negatively for p53 protein. Three out of 11 (27·3 per cent) epithelial dysplasias and 19 out of 57 (33·3 per cent) primary squamous cell carcinomas stained positively for p53 protein. Although more than half of the cases were positive for p53 protein in stage I, the positive cancer cases were found at other stages with variable frequency. Immunoreactive products were localized in the nucleus, especially in the basal and suprabasal layers. The analysis by TGGE revealed gene alterations in exons 5–8 in 3 out of 3 epithelial dysplasias and 17 out of 19 (89·5 per cent) primary squamous cell carcinomas which were immunohistochemically positive for p53 protein. These results suggest that p53 gene mutation may be involved in carcinogenesis in the oral squamous epithelium even in the early stage of the dysplasia–carcinoma sequence.     

Mucoepidermoid Carcinoma of the Esophagus

The esophageal tumor which occurred in a 53-year old female and was histologically similar to the salivary mucoepidermoid carcinoma, showed local invasion at autopsy. No distant metastasis was noted. Our literature review showed invasive and metastatic nature of the tumor. Submucosal location of the tumor in our case supported the proposed origin of the neoplasm from the esophageal gland.