Absence of chromosome 19q13.41 amplification in a case of atypical teratoid/rhabdoid tumor with ependymoblastic differentiation

Excerpt

The primitive neuroectodermal tumors of central nervous system (CNS-PNET) are a heterogeneous group of neoplasms which are composed of undifferentiated or poorly differentiated neuroepithelial cells and may display divergent differentiation along neuronal, astrocytic and ependymal lines [6]. This group of tumors also includes ependymoblastoma as well as medulloepitheliomas. Several groups have reported examples of embryonal tumors with combined histological features of ependymoblastoma and neuroblastoma defined as “embryonal tumor with abundant neuropil and true rosettes” [2]. Both ependymoblastoma (EPBL) and embryonal tumor with abundant neuropil and true rosettes (ETANTR) present ependymoblastic multilayered rosettes, occur typically in infants and share a very aggressive clinical behavior [2]. The presence of a focal high-level amplification at chromosome 19q13.41, common to both ETANTR and EPBL, may suggest that they represent a histological spectrum of a single biological entity [4, 7]. The chromosome 19q13.41 locus spans a large, poorly characterized, miRNA cluster C19MC and the miR-371-373 locus [5]. Although miR371-373 has been implicated in germ cell tumors, little is known regarding the C19MC locus that encodes various miRNA species, some of them with oncogenic potential (e.g. miR-520g and 517c) [5]. …