Eberhart et al listed histopathologic features of medulloblastomas. These can help standardize the descriptions. The authors are from the Johns Hopkins University, University of Florida at Gainseville, St. Jude Children's Research Hospital, Duke University, and Texas Children's Hospital in Houston.
Parameters:
(1) nodularity
(2) desmoplasia
(3) grade of anaplasia
(4) extent of anaplasia
(5) mitotic rate per 10 high powered fields (adjusted for field area)
|
Parameter |
Finding |
Description |
|
nodularity |
absent (0%) |
none |
|
|
1 - 10% |
slight |
|
|
11 - 50% |
moderate |
|
|
51 - 95% |
widespread |
|
|
96 - 100% |
extensive |
|
desmoplasia |
|
absent |
|
|
|
present |
|
grade of anaplasia |
crowded regions without increased nuclear size |
no anaplasia |
|
|
cells with slight nuclear enlargement, nuclear molding, scattered mitoses, scattered apoptosis |
slight anaplasia |
|
|
enlarged nuclei, wrapping of tumor cells, common mitosis, common apoptosis |
moderate anaplasia |
|
|
enlarged nuclei, wrapping of tumor cells, frequent mitoses, large clusters of apoptotic cells |
severe anaplasia |
|
extent of anaplasia |
none |
none |
|
|
not present in all low-powered microscopic fields |
focal |
|
|
present in all low-powered microscopic fields |
diffuse |
where:
• The features of anaplasia included increased mitotic activity, enlarged nuclear size, apoptosis, and subtype (see below).
• The nuclei in moderate anaplasia are about twice the diameter of an RBC. In severe anaplasia the nuclei are 2-3 times the diameter of an RBC.
• Severe anaplasia may occur as either large cell or anaplastic subtypes. The large cell subtype has round nuclei and prominent nucleoli. The anaplastic subtype has angular, crowded, pleomorphic nuclei with the cells wrapped around each other.
The presence of moderate or severe anaplasia was associated with a worse long-term survival compared to patients with no or slight anaplasia.
|
Anaplasia |
Probability of 10 Year Survival |
|
none or slight |
60% |
|
moderate to severe |
35% |
from Figure 5, page 557
Specialty: Hematology Oncology, Surgery, general, Neurology
