Atypical Teratoid Rhabdoid Tumor

Atypical Rhabdoid/Teratoid Tumors (ATRTs) are a type of embryonal tumors seen in infants and children. They are rare, malignant, and most commonly arise in the posterior fossa, although they can arise elsewhere. The tumor cells have the morphology shown here. Cells have an eccentrically placed nucleus, prominent nucleoli (unnecessarily large green arrow) and abundant cytoplasm which is eosinophilic and granular. Also characteristic are regions of darker, more dense cytoplasm, referred to as inclusion-like bodies (unnecessarily large red arrow).