Gleason pattern 5

Gleason pattern 5 consists of individual cells, cords of cells, and sheets of tumor.

Although typically one sees comedonecrosis with solid nests, occasionally one can see necrosis with cribriform masses that by themselves might be cribriform pattern 4.

If there is true comedonecrosis, the consensus was that these patterns should be regarded as Gleason pattern 5.

One must be stringent as to the definition of comedonecrosis, requiring intraluminal necrotic cells and/or karyorrhexis, especially in the setting of cribriform glands.

In two studies using different patient populations, there is a tendency for pathologists to undergrade Gleason pattern 5 in almost 50% of cases sent for a second opinion at the request of the patient of urologist where this author has diagnosed Gleason pattern 5.

Pattern 5 was missed more frequently when it was not the primary pattern.

References

 Gleason pattern 5 is frequently underdiagnosed on prostate needle-core biopsy. Al-Hussain TO, Nagar MS, Epstein JI. Urology. 2012 Jan;79(1):178-81. PMID: 22035764

 Identification of Gleason pattern 5 on prostatic needle core biopsy: frequency of underdiagnosis and relation to morphology. Fajardo DA, Miyamoto H, Miller JS, Lee TK, Epstein JI. Am J Surg Pathol. 2011 Nov;35(11):1706-11. PMID: 21997691