Medullomyoblastoma: A radiographic and clinicopathologic analysis of six cases and review of the literature

Abstract

BACKGROUND Medullomyoblastoma (MMB) is a rare cerebellar embryonal neoplasm that occurs almost exclusively in children. It is biphasic by microscopy, containing myoblastic and primitive neuroectodermal components. METHODS The authors conducted a retrospective review of the radiographic and pathologic characteristics, treatment, and clinical outcomes of six children with MMB who were treated at St. Jude Children's Research Hospital (Memphis, TN) between 1984 and 2003. Fluorescence in situ hybridization (FISH) data were available for four children. A literature review also was conducted and focused on imaging and pathologic findings. RESULTS The median age at diagnosis was 4.5 years (range, 0.83–7.5 years). Radiographically, all tumors were cerebellar and exhibited variable enhancement, and 50% of tumors had necrotic foci. Three tumors contained discrete, magnetic resonance imaging (MRI) T2‐weighted–hypointense/computed tomography (CT)‐hyperdense enhancing regions and separate hyperintense/hypodense nonenhancing regions, which correlated microscopically with geographic islands of primitive neuroectodermal and rhabdomyoblastic cells. Large cell/anaplastic (five tumors), nodular/desmoplastic (two tumors), and classic (two tumors) medulloblastoma histologies were encountered either alone (five tumors) or in combination with each other (two tumors). All 4 tumors that were tested exhibited alterations in chromosome 17 or c‐myc amplification. All patients underwent macroscopic total resection and subsequently received chemotherapy and craniospinal (five patients) or local conformal (one patient) radiotherapy. At a median follow‐up of 92 months (range, 23–187 months), 3 patients remain alive with no evidence of disease, 2 patients have died of disease, and 1 patient has died of secondary acute lymphocytic leukemia. CONCLUSIONS The results of the current study demonstrated the frequent correlation of biphasic nodularity (as determined by MRI or CT) with discrete rhabdomyoblastic and primitive neuroectodermal islands (as revealed by microscopy) in MMB. These results also support the view that MMB and medulloblastoma may have common tumorigenic origins, given their similar histologic and molecular features. Cancer 2004. © 2004 American Cancer Society.

Credentialing Preclinical Pediatric Xenograft Models Using Gene Expression and Tissue Microarray Analysis

“…This is not surprising given the fact that both of these groups of cancers have been reported on occasions to express muscle markers. Indeed, meduloblastomas are a heterogeneous group of cancers and the majority of reported cases in the literature have been biphasic, containing both primitive neuroectodermal and rhabdomyoblastic cells (33,34). Within our database, all three of these tumors were found to have the highest expression of insulin-like growth factor II in each of their cancer types at levels comparable with levels in rhabdomyosarcoma (data not shown; see on-line database).…”

The 2007 WHO Classification of Tumours of the Central Nervous System

“…The code remains but since its clinical features and genetic profile are similar to those of other medulloblastomas, this lesion is no longer considered a distinct entity [14, 34] and it is suggested that the code for medulloblastoma (9470/3) be applied. The descriptive term ‘medulloblastoma with myogenic differentiation’ may be used for any variant (desmoplastic/nodular, large cell medulloblastoma, etc.)…”

OTX2 Represses Myogenic and Neuronal Differentiation in Medulloblastoma Cells

“…A secondary description termed Medullomyoblastoma exits for the medulloblastoma with variously differentiated myogenic cells mixed with the tumor cells (2). It is featured with rhabdomyoblastic elements immuno-reactive to desmin, myoglobin and fast myosin (3). …”

“…MMB makes up 3–5% of all medulloblastoma cases and the features of this tumor may provide important clues to the pathogenesis of this embryonal tumors (22, 23). MMB’s distinguishing feature is the presence of cells showing muscle differentiation among the primitive neuroectodermal tumor cells that characterize medulloblastomas (3). These myogenic elements in MMB can be found in various differentiation phases, ranging from myoblastic single cells to well developed striated muscle structure (24).…”