An ultrastructural study of lipodystrophia centrifugalis abdominalis infantilis, with special reference to fibrous long-spacing collagen.

Lipodystrophia centrifugalis abdominalis infantilis (LCAI) in a 2.5-year-old Japanese girl is reported. Clinically she had a curved cutaneous depression with a slightly elevated erythematous border on the left abdomen beyond the left groin. The regional lymph node was palpable. Histologic examination showed a decrease of the fat, an inflammatory infiltrate mainly composed of lymphocytes, and septal fibrosis in the subcutaneous tissue. Immunohistochemical analysis found that infiltrating lymphocytes were mainly positive against CD4. Ultrastructurally nuclei in the adipocytes were crescent shaped and located toward the periphery of the cell. Some banded structures with a periodicity of 150 nm, and with intraperiodic bands, referred to as fibrous long-spacing collagen (FLSC), were observed in the septal area of the fatty tissue. These results indicated that FLSC was correlated with the breakdown of fibrillar collagens in LCAI.