HISTOPATHOLOGIC AND ULTRASTRUCTURAL-STUDY OF LUPUS-LIKE SKIN-LESIONS IN A PATIENT WITH BLOOM-SYNDROME

The histopathology of the lupus-like skin lesions associated with Bloo m syndrome has been sporadically described. Skin biopsies from a 2-yea r-old boy with the classical features of Bloom syndrome, including lup us-like skin lesions, demonstrated marked interface changes with basal liquefaction degeneration, a moderate superficial mononuclear infiltr ate, pigmentary incontinence, and capillary dilation in the papillary dermis. Immunophenotyping of the dermal infiltrate revealed predominan ce of T-cells. Basement membrane thickening on periodic acid-Schiff ex amination was not seen. Direct immunofluorescence failed to demonstrat e deposits of immunoglobulin other than nonspecific IgM deposition alo ng the basement membrane zone of lesional skin. Ultrastructurally, the most striking findings were disintegration of basal cell cytoplasm an d tubuloreticular inclusions in vascular endothelia. Taken together, t he histologic and ultrastructural features of lupus-like lesions assoc iated with Bloom syndrome mimic those of cutaneous lupus erythematosus , with the exception of paucity of immune deposits at the dermoepiderm al junction.