Interobserver reproducibility of Gleason grading of prostatic carcinoma: urologic pathologists.

Gleason grading is now the most widely used grading system for prostatic carcinoma in the United States. However, there are only a few studies of the interobserver reproducibility of this system, and no extensive study of interobserver reproducibility among a large number of experienced urologic pathologists exists. Forty-six needle biopsies containing prostatic carcinoma were assigned Gleason scores by 10 urologic pathologists. The overall weighted kappa coefficient kappa(w) for Gleason score for each of the urologic pathologists compared with each of the remaining urologic pathologists ranged from 0.56 to 0.70, all but one being at least 0.60 (substantial agreement). The overall kappa coefficient kappa for each pathologist compared with the others for Gleason score groups 2-4, 5-6, 7, and 8-10 ranged from 0.47 to 0.64 (moderate-substantial agreement), only one less than 0.50. At least 70% of the urologic pathologists agreed on the Gleason grade group (2-4, 5-6, 7, 8-10) in 38 ("consensus" cases) of the 46 cases. The 8 "nonconsensus" cases included low-grade tumors, tumors with small cribriform proliferations, and tumors whose histology was on the border between Gleason patterns. Interobserver reproducibility of Gleason grading among urologic pathologists is in an acceptable range.

Interobserver reproducibility of Gleason grading of prostatic carcinoma: general pathologist.

Only a few large studies of interobserver reproducibility of Gleason grading of prostatic carcinoma exist. Thirty-eight biopsies containing prostate cancer were distributed for Gleason grading to 41 general pathologists in Georgia. These cases had "consensus" Gleason grade groups (2-4, 5-6, 7, and 8-10) that were agreed on by at least 7 of 10 urologic pathologists. The overall kappa (kappa) coefficient for interobserver agreement for these 38 cases was 0.435, barely moderate agreement, with a kappa range from 0.00 to 0.88. There was consistent undergrading of Gleason scores 5-6 (47%), 7 (47%) and, to a lesser extent, 8-10 (25%). In cases with consensus primary patterns, there was consistent undergrading of patterns 2 (32%), 3 (39%), and 5 (30%). Pattern 2 was often (17%) mistaken for pattern 3. Pattern 4 was often undergraded (21%) and also mistaken for pattern 5 (17%). The most significant (P < .005) demographic factor associated with better interobserver agreement was having learned Gleason grading at a meeting or course. We believe that Gleason grading can be learned to a satisfactory level of interobserver reproducibility and have undertaken additional studies that support this belief.

Needle biopsies of the prostate: what constitutes adequate histologic sampling?

OBJECTIVE: The automated biopsy gun and increased screening for adenocarcinoma of the prostate have led to increased numbers of biopsies with only tiny foci of prostatic carcinoma. Consequently, the risk of failing to sample a small focus of carcinoma histologically has increased as well. Most pathologists routinely sample prostatic needle biopsies at more than 1 level. An expert panel has recently suggested that prostatic needle biopsies be sampled at at least 2 levels. However, there have been no studies measuring the amount of additional tissue sampled by multiple levels versus 1 level. METHODS: Forty-two prostatic needle biopsies were serially sectioned at 4-microm levels. Hematoxylin-eosin-stained slides were prepared from every fifth section. The total length of each biopsy was compared with the length sampled by 1 level (50% through the block) and 3 levels (25%, 50%, and 75% through the block). RESULTS: Sampling the tissue at 1 level missed an average of 23.4% of the total biopsy length. Sampling the tissue at 3 levels significantly improved this average to 7% (P = .0001). CONCLUSIONS: This study shows that a single histologic section of a prostatic needle biopsy often fails to sample a significant portion of available tissue. This could occasionally result in failure to sample a small focus of prostatic carcinoma. The authors recommend that prostatic needle biopsies be routinely sampled at 3 levels (approximately 25%, 50%, and 75% through the block).

Anaplastic carcinoma occurring in association with a mucinous cystic neoplasm of the pancreas.

Anaplastic carcinomas of the pancreas are considered variants of ductal adenocarcinoma. They typically occur in elderly men. They have rarely been reported to occur in association with mucinous cystic neoplasms of the pancreas. We report a case of anaplastic carcinoma occurring in association with a pancreatic mucinous cystic neoplasm, borderline-type, in a 25-year-old woman who presented with lymph node and hepatic metastases.