Gleason described 5 major histologic patterns of prostatic adenocarcinoma, which range from well to poorly differentiated.
The Gleason grades range from 1 (well-differentiated) to 5 (poorly differentiated). Grades 4 and 5 show 2 subtypes (A and B) while Grade 3 has 3 subtypes (A, B. C).
The Gleason score is the combination of the 2 most common patterns seen in the histologic sections.
Gleason score =
= (number grade for most common pattern) + (number grade of the second most common pattern)
The Gleason score may range from 2 to 10. The higher the score the worse the prognosis.
The histologic grades tend to occur in 4 major patterns:
(1) small to medium malignant glands that are separate from each other
(2) large malignant glands
(3) fused malignant glands
(4) solid tumor with no or rare glands-like structures
Small to Medium Glands
|
Description of Tumor |
Advancing Edge |
Grade |
|
closely packed glands that are similar in size and separate |
smooth, pushing, regular, well-circumscribed |
1 |
|
closely packed glands that vary in size and separate |
less regular and less well circumscribed than Grade 1 |
2 |
|
closely packed glands that are variable in size and separate |
irregular, ill-defined |
3A |
|
small glands packed close together but separate |
irregular, ill-defined |
3B |
Large Malignant Glands
|
Description of Tumor |
Advancing Edge |
Grade |
|
variable size glands packed close together but separate |
irregular, ill-defined |
3B |
|
elongated glands with papillary and cribriform growth |
expansive |
3C |
|
masses and cylinders; central necrosis (comedonecrosis) |
expansive |
5A |
Fused Malignant Glands
|
Description of Tumor |
Advancing Edge |
Grade |
|
masses, cords and chains |
diffuse permeation with ragged edge |
4A |
|
masses, cords and cylinders with clear cells (hypernephroid) |
diffuse permeation with ragged edge |
4B |
Solid Tumor
|
Description of Tumor |
Advancing Edge |
Grade |
|
sheets, cords and single anaplastic cells; signet ring cells |
diffuse permeation with ragged edge |
5B |
Specialty: Hematology Oncology, Surgery, general, Urology
ICD-10: ,
