Malpica et al developed a two tier (low grade, high grade) histologic grading system for ovarian serous carcinoma. The authors are from the University of Texas M.D. Anderson Cancer Center, Memorial Sloan Kettering Cancer Center and several other university hospitals in the United States.
Grading is based on the histologic features in the "worst" area of the tumor.
Primary histologic parameters:
(1) variation in size (based on ratio of largest to smallest nucleus)
(2) uniformity of nuclear shape
(3) chromatin pattern
Secondary histologic parameters (only used if primary histologic features are equivocal):
(1) mitotic index
Parameter |
Low Grade |
High Grade |
variation in size |
little |
marked (nuclear size ratio >= 3) |
nuclear shape |
uniform round to oval with little variation |
marked variation |
chromatin |
even to slightly irregular |
marked variation |
mitotic index |
<= 12 mitoses per 10 hpf |
> 12 mitoses per 10 hpf |
where:
• The textual description does not include intermediate features. There are 2 ways to handle these values - (1) score them as high grade features or (2) assign an intermediate score. In the implementation points are assigned as 0 if low grade, 0.5 if intermediate and 1.0 if high grade. The primary 3 features are summed. If the score is >= 1.5 it is high grade, if <= 0.5 low grade, else (score 1.0) the grade is determined by the mitotic index.
• Hpf = high power microscopic field (40x objective). Using a count per square mm would probably be more precise.
• Both low grade and high grade tumors can show prominent nucleoli.
Performance:
• Malpica et al (2007) reported good interobserver and intraobserver performance.
Limitations:
• Multiple sections need to be examined and the least differentiated area selected for the grading.
Purpose: To grade the histologic features of an ovarian serous carcinoma using the two-tier scheme of Malpica et al.
Specialty: Hematology Oncology, Surgery, general, Obstetrics & Gynecology
Objective: laboratory tests, severity, prognosis, stage
ICD-10: C56,