Inclusion Body Myofibroblasts Other than Those Seen in Recurring Digital Fibroma of Childhood

The authors thank Drs. I. Gonzalez-Mediero, M. D. Sanchez-Larrea, and J. P. Colomar (Anatomic Pathology, Hospital del Niño Jesus, Madrid, Spain) for sending us both cases of recurring digital fibroma of childhood for ultrastructural study. We are also grateful to Mr. A. Mendez, Mr. F. Sanchez-Margallo, and Mr. J. L. Mota, ATSs of the Electron Microscopy Laboratory for their technical help. Four patients of the toxic oil epidemic syndrome (TOES), which took place in Spain in 1981, showed a dermohypodermal fibroblastic process with round eosinophilic cytoplasmic inclusions (ECI) in the proliferating cells. Light and electron microscopic studies revealed that those cells had myofibroblastic features and that the ECI were identical to those seen in recurring digital fibroma of childhood (RDFC). Two cases of RDFC, involving the fingers of 6-month-old and 2-year-old patients, were examined by light and electron microscopy for comparative study. The 4 patients of TOES, aged 14 to 46 years, showed generalized sclero-dermalike skin changes, and skin biopsies were obtained from the anterior wall of the abdomen and retromaleolar region of the left leg. The ultrastructural study of the ECI and the initiating changes leading to them allowed us to suggest a cytoskeletal origin for these inclusions.