Apoptotic index from fine needle aspiration cytology as a criterion to predict histologic grade of non-Hodgkin's lymphoma.
OBJECTIVE
To investigate whether the assessment of apoptotic index (AI) from fine needle aspiration (FNA) smears of non-Hodgkin's lymphomas (NHL) is reliable and has potential utility as a criterion to predict histologic grade.


METHODS
AI was independently determined by four cytopathologists as a percentage from routine FNA smears in 96 NHLs and 15 lymphoid hyperplasias. Working formulation (WF) grades from corresponding surgical biopsies were modified to include mantle zone-derived NHLs as intermediate grade and to make diffuse large cell NHL a separate category called "high" grade, whereas WF high grade NHLs were called "very high" grade. Histologic grades were also derived from the Revised European American Lymphoma (REAL) classification. AI was compared with histologic grade using the unpaired, two-tailed Student t test. These data were used to determine potential thresholds for AI that separate lower from higher grade NHLs.


RESULTS
Measurements of AI strongly correlated between cytopathologists (median r = .93). Low and intermediate grade NHLs had indistinguishable AIs, whereas higher grade NHLs had significantly higher AIs. Appropriate potential AI thresholds between low or intermediate grade and higher grade NHLs were in the range of 1.5-2.5% (modified WF) and 1-2% (REAL).


CONCLUSIONS
There is excellent interobserver reliability in the measurement of AI from FNAs of NHLs. Higher AIs distinguish higher from lower grade NHLs. Diffuse large cell NHLs had AIs that were similar to WF high grade NHLs.
Symmans
W F
WF
Department of Pathology, New York University Medical Center, New York 10016, USA.
Cangiarella
J F
JF
Symmans
P J
PJ
Cohen
J M
JM
Yee
H T
HT
Bennett
G
G
Amorosi
E L
EL
Waisman
J
J
D017209:Apoptosis; D001707:Biopsy, Needle; D006801:Humans; D008228:Lymphoma, Non-Hodgkin / Q000145:classification / Q000473:pathology*; D015588:Observer Variation; D019310:Pseudolymphoma / Q000145:classification / Q000473:pathology; D015203:Reproducibility of Results