Specific features of childhood brain tumors may help guide prognosis

Nov 13 2008

Specific histologic features of childhood medulloblastomas may provide insight into prognosis, according to an article in the new issue of Pediatric and Developmental Pathology.

Medulloblastomas are common, malignant, embryonal childhood tumors in the cerebellum. Individual histologic features such as nodules, balls or high cell density are used to divide the tumors into variants thought to modify survival estimates. The WHO classification of these tumors includes desmoplastic/nodular (DM), medulloblastoma with extensive nodularity (N), large cell medulloblastoma (LC), and anaplastic medulloblastoma (A).

During their research, the article's authors found a difference in survival distribution for six features of medulloblastomas: high cell density, fine fibrillary stroma, necrosis, nodules, balls and prominent nucleoli. The presence of nodules, balls, fine fibrillary stroma and high cell density improved the survival outlook, whereas necrosis and prominent nucleoli worsened it.

"The presence of nodularity in medulloblastoma is important to improved survival likelihood, particularly when combined with balls and fine fibrillary stroma," according to the article "Histologic Features and Prognosis in Pediatric Medulloblastoma," by Shalini Verma, C. Jane Tavare, and Floyd H. Gilles. "Given the WHO-acknowledged 'overlap' of desmoplastic/nodular medulloblastoma and nodular medulloblastoma, we suggest these diagnoses be combined into a diagnosis of nodular medulloblastoma, with nodules, balls, and fine fibrillary stroma as defining criteria."

The article also contends that three histologic features vital for LC and A diagnoses - large and intermediate size nuclei and prominent nucleoli - have poor read-reread reliability and suggests these be combined into a diagnosis of anaplastic/large cell medulloblastoma.

To read the entire study, http://www3.allenpress.com/pdf/pdpa_11.5_i1615-5742-11-5-337.pdf

Pediatric and Developmental Pathology is published by the Society for Pediatric Pathology and the Pediatric Pathology Society. Pediatric and Developmental Pathology is the premier journal dealing with the pathology of disease from conception through adolescence. For more information, see www.pedpath.org