Adenoid glioblastoma: Stromal hypovascularity and secretion of chondromodulin‐I by tumor cells

The case of a 75-year-old man with a glioblastoma of the right frontal lobe showing features of adenoid glioblastoma is reported. The tumor consisted of two components: the adenoid component, in which large, cohesive, polygonal cells with vesicular nuclei and abundant basophilic cytoplasm showed nest-like, trabecular, or tubular growth on the myxoid matrix and formed a multinodular configuration; and the subsidiary component, in which short spindle cells showed compact fascicular growth. The features of ordinary glioblastoma were also found in a small area. Tumor cells were immunoreactive for S-100 protein, glial fibrillary acidic protein, and Olig2, and some tumor cells in the adenoid component showed immunoreactivity for cytokeratins and E-cadherin. A marked regional decrease in microvascular density, approaching almost complete absence of microvessels, was demonstrated in the adenoid component. In contrast, microvascular density was well preserved in the spindle cell component and the area of ordinary glioblastoma. Tumor cells in the adenoid component showed cytoplasmic expression of chondromodulin-I, one of the cytokines that strongly inhibit angiogenesis, whereas the expression of this protein was very weak or only faint in the spindle cell component and the area of ordinary glioblastoma. A marked regional decrease in microvascular density was associated with myxoid change of the stroma and considered to be caused by the secretion of chondromodulin-I by tumor cells. Stromal hypovascularity with myxoid change might play an important role in the morphogenesis of adenoid features.