chapter  26
Desmoplastic infantile astrocytoma/desmoplastic infantile ganglioglioma
ByMarc K. Rosenblum
Pages 12

Among those intracranial neoplasms that principally arise in early life are to be found certain neuroepithelial tumors having in common a superficial, largely extracerebral positioning within the supratentorial compartment, a tendency to prominent cystic change, a pseudomesenchymal histologic presentation typified by conspicuous collagenization and the deceptive spindling of included astrocytic forms, and – their often intimidating dimensions and frequent harboring of poorly differentiated cellular populations notwithstanding – favorable outcomes following resection. What are now reasonably and widely regarded as subtypes within this unified group were characterized by Taratuto and coworkers (1984) as ‘superficial cerebral astrocytomas attached to dura’ and by VandenBerg et al. (1987) as ‘desmoplastic supratentorial neuroepithelial tumors of infancy with divergent differentiation potential’ or, more succinctly, ‘desmoplastic infantile gangliogliomas’. The latter series was based mainly on material referred in consultation to Dr Lucien Rubinstein and included four neoplasms (cases 1, 3, 9, and 10) previously reported as desmoplastic variants of cerebral neuroblastoma presenting in infants (Horten and Rubinstein, 1976, cases 32-35). In retrospect, the ‘complex cerebral tumor with evidence of neuronal, glial, and Schwann cell differentiation’ depicted by Gambarelli and colleagues (1982) would seem to belong in this family. Save for the presence of differentiated

neuronal elements in the subset defined by VandenBerg et al. (1987), the morphology, neuroradiologic features, and clinical biology of the neoplasms collected under these designations have proven indistinguishable. Accordingly, these are extended the allying designation of ‘desmoplastic infantile astrocytoma/ganglioglioma’ in the current WHO classification of nervous system tumors (Taratuto et al., 2000) and are given joint treatment in this chapter. The diagnostic terminology appropriate to a given case, a matter of no practical consequence, depends alone on whether differentiation can be shown to proceed solely along astroglial lines (desmoplastic infantile astrocytoma) or includes the generation of patently neuronal forms (desmoplastic infantile ganglioglioma). It has been our practice to include under the latter rubric examples that do not contain ganglion cells or other elements readily identifiable as neoplastic neurons but that harbor morphologically ambiguous populations immunoreactive for neuron-associated antigens.