Variability in Diagnostic Opinion Among Pathologists for Single Small Atypical Foci in Prostate Biopsies

Abstract

Pathologists are increasingly exposed to prostate biopsies with small atypical foci, requiring differentiation between adenocarcinoma, atypical small acinar proliferation suspicious for malignancy, and a benign diagnosis. We studied the level of agreement for such atypical foci among experts in urologic pathology and all-round reference pathologists of the European Randomized Screening study of Prostate Cancer (ERSPC). For this purpose, we retrieved 20 prostate biopsies with small (most <1 mm) atypical foci. Hematoxylin and eosin-stained slides, including 10 immunostained slides were digitalized for virtual microscopy. The lesional area was not marked. Five experts and 7 ERSPC pathologists examined the cases. Multirater kappa statistics was applied to determine agreement and significant differences between experts and ERSPC pathologists. The kappa value of experts (0.39; confidence interval, 0.29-0.49) was significantly higher than that of ERSPC pathologists (0.21; confidence interval, 0.14-0.27). Full (100%) agreement was reached by the 5 experts for 7 of 20 biopsies. Experts and ERSPC pathologists rendered diagnoses ranging from benign to adenocarcinoma on the same biopsy in 5 and 9 biopsies, respectively. Most of these lesions comprised between 2 and 5 atypical glands. The experts diagnosed adenocarcinoma (49%) more often than the ERSPC pathologists (32%) (P<0.001). As agreement was particularly poor for foci comprising <6 glands, we would encourage pathologists to obtain intercollegial consultation of a specialized pathologist for these lesions before a carcinoma diagnosis, whereas clinicians may consider to perform staging biopsies before engaging on deferred or definite therapy.

Interobserver variations in reporting of prostatic adenocarcinoma using core biopsy specimens: a retrospective study from a tertiary referral hospital in Saudi Arabia

“…Inconclusive interpretations were mostly due to the presence of small atypical or atrophic acini. These findings are keeping with those reported in the literature (7,(12)(13)(14)(15).…”

“…Increasing the number of needle cores analysed to between 6 to 12 has been shown to improve prostate cancer detection by 29% (4,5). For this reason, a greater number of prostate biopsies are obtained nowadays and more biopsy cores are being submitted than ever before and this has created a huge interpretive burden for the diagnostic histopathologist (6), a burden that is exacerbated by the difficulties of prostate biopsy interpretation (6,7).…”

On the relationship between tumor structure and complexity of the spatial distribution of cancer cell nuclei: A fractal geometrical model of prostate carcinoma

“…The second parameter seems to be well correlated with clinical outcome [13]. However, the subjectivity of tumor grading leads to the significant inter-and intra--observer variability of 40-80% [14][15][16][17][18][19] associated with the coefficient k for interobserver agreement 0. 15-0.7 [15,20-22].…”

Bedeutung der Zweitmeinung bei Prostatabiopsien

“…Wie jüngste Untersuchungen gezeigt haben, werden derartige winzige atypische Drü-senherde im HE-Schnitt, auch von international bekannten uropathologischen Experten, sehr unterschiedlich beurteilt [40]. Wie aus früheren Untersuchungen und der Literatur hervorgeht, werden unter Einsatz der Immunhistochemie mit Basalzellmarkern wie 34βE12 (zytoplasmatisch) und p63 (nukleär) sowie P504 SRazemase oder PIN-Cocktail in 35-50% der Fälle von ASAP Karzinome gesichert.…”