SOFT-TISSUE GLIOMATOSIS - MORPHOLOGIC UNITY AND HISTOGENETIC DIVERSITY

Normal-appearing tissues in non-native sites constitute one of the mor e common morphologic expressions of abnormal development, The presence of pancreas in the wall or on the serosa of the small intestine and a drenal cortical tissue in a hernia sac are two familiar examples of he terotopias. We report our experience of mature glial tissues in the so ft tissues of six children who were between the ages of 4.5 months and 2 years when they presented with a solitary mass on the chest wall (t hree cases), scalp (two cases) and gluteal region (one case). These tu mors were all characterized by pale-staining fibrillary foci of mature neuroglia, which were intensely immunoreactive for glial fibrillary a cidic protein in each case. One of the two scalp lesions was accompani ed by a nodule of cartilage and a meshwork of pseudovascular spaces, w hich were decorated with antibodies to vimentin and epithelial membran e antigen consistent with meningothelial tissue. The histogenesis of t he neuroglial tissue in the gluteal region and scalp was, respectively , on the basis of a recurrence of a sacrococcygeal teratoma in the for mer case and sequestered encephaloceles in the last two cases. A facil e explanation for the occurrence of neuroglial tissue in the soft tiss ue of the chest wall in the remaining three cases was less than obviou s as none of the patients had accompanying neurologic or anatomic defe cts and all were in a nonmidline location. These three cases of soft t issue gliomatosis of the chest wall are similar to an earlier example in the recent literature whose histogenesis was as enigmatic as it pro ved to be in our three cases. Although the histologic and immunohistoc hemical features of these six cases were very similar in each instance , their origin varied from a recurrent sacrococcygeal teratoma and seq uestered encephaloceles to essentially unknown.