CNS tumor
Embryonal tumors

Author: Nirupama Singh M.D., Ph.D.
Editor: Paul J. Biggs M.D.
Deputy Editor Review: Debra Zynger, M.D.

Revised: 1 August 2018, last major update January 2018

Copyright: (c) 2002-2018,, Inc.

PubMed Search: Neuroblastoma[title] CNS

Page views in 2018: 3,116
Page views in 2019 to date: 271
Cite this page: Singh, N. Neuroblastoma. website. Accessed January 23rd, 2019.
Definition / general
  • Third most common extracranial solid tumor of childhood after leukemia and brain tumors, but cranial neuroblastomas are very rare
  • Characterized by poorly differentiated neuroepithelial cells, groups of neurocytic cells and a variable neutropil rich stroma
Essential features
  • Sheets of densely packed primitive embryonal cells are seen in a lobulated pattern in a fibrillary background
ICD coding
  • C71: malignant neoplasm of brain
  • Occur at a wide variety of locations along the sympathetic chain
  • Most common site is abdomen and pelvis (40% in adrenal medulla)
  • Occur occasionally in mediastinum and neck and rarely in brain
  • Diagnosed before 5 years of age with median age of 17.3 months
  • Adrenal gland (40%)
  • Abdominal and thoracic ganglia (40%)
  • Cervical ganglia (5%)
  • Rarely paratesticular and brain
  • WHO grade IV
Prognostic factors
  • All CNS neuroblastomas are WHO grade IV but survival varies from 40 - 90% based on age, histology, MYCN amplification and DNA ploidy
Case reports
  • Treatment modalities differ based on clinical subgroups, and include observation, surgical resection, chemotherapy, radiation therapy, stem cell transplantation, immunotherapy
Clinical features
  • Abdominal mass, Horner syndrome (ptosis, miosis, anhydrosis)
  • Nonspecific clinical signs of fever, weight loss and fatigue can be present along with bone pain
  • Hematogenous spread to bone and bone marrow is commonly followed by metastases to lymph nodes and lungs
  • Peripheral neuroblastoma is classified in subgroups based on patient age, postsurgical stage, MYCN amplification, histology and DNA ploidy
Microscopic (histologic) description
  • Poorly differentiated neuroepithelial cells and neurocytic cells in the background of neuropil rich stroma
  • Poorly differentiated neuroblast cells have little to no apparent cytoplasm in a background of neuropil with or without Homer Wright rosettes
  • Differentiating neuroblastoma subtype has abundant neuropil with differentiating neuroblasts seen as ganglionic differentiation with eosinophilic cytoplasm and enlarged, eccentric nucleus with prominent nucleolus
Microscopic (histologic) images

Images hosted on PathOut server:

Images contributed by Nirupama Singh M.D., Ph.D.

Neuroblasts with no cytoplasm (10x)

Homer Wright rosettes (40x)

Small tumor cells (40x)

Images contributed by Carmen Perrino, M.D.

High power pseudorosettes

Images hosted on other servers:

Neuroblastoma of the adrenal gland

Positive stains
Negative stains
Differential diagnosis
Board review question #1
A 2 year old patient presents with back pain and lower extremity weakness. CT scan demonstrates a paraspinal / dumbbell mass compressing the cord at L2. The most likely diagnosis is:

  1. Ewing sarcoma
  2. Lymphoma
  3. Neuroblastoma
  4. Wilms tumor
Board review answer #1
C. In this age group neuroblastoma is the most common of these tumors.
Board review question #2
According to The International Neuroblastoma Pathology Classification, which features are prognostic factors for neuroblastoma?

  1. Age, histologic classification and mitosis karyorrhexis index (MKI)
  2. Age, tumor alveolar histology and DNA index (ploidy)
  3. Age, tumor cell apoptosis and MYCN amplification
  4. Age, tumor cell differentiation and necrosis
Board review answer #2
A. Prognostic variables for neuroblastoma include age, stage, and histologic classification, grade of tumor differentiation, MYCN status, and DNA index (MKI). Histology is graded according to the International Neuroblastoma Pathology Classification (INPC) which evaluates for degree of tumor cell differentiation and mitosis karyorrhexis index as related to age (less than or greater than 18 months) to define favorable or unfavorable histology.