Use of the immunostaining results significantly improved both diagnostic accuracy and interobserver agreement. These results indicate that ovarian carcinoma type can be reliably diagnosed by pathologists from different countries, and also demonstrate that immunohistochemistry has an important role in improving diagnostic accuracy and agreement between pathologists.

Elderly men with category T1a and/or Gleason score 4-5 prostate cancer have a favourable prognosis with conservative management. Immunohistochemical staining with Ki-67 may be of help in situations where further prognostic information is required.

Grading and histologic typing of endometrial cancer in biopsy material has a direct impact on the decision to perform lymphadenectomy and/or omentectomy in many cancer centers. Endometrial biopsies are among the most common general surgical pathology specimens. Multiple studies have shown that biopsy diagnosis suffers from a lack of reproducibility. Although many biomarkers have been proposed, none have been demonstrated to improve the diagnosis in the biopsy setting. In this study, 70 biopsies with endometrial carcinoma were supplemented with a biomarker panel consisting of ER, PR, P53, and DNA ploidy. A representative H&E slide was scanned digitally and made available to 12 gynecologic pathologists in 4 Nordic countries: Finland, Denmark, Sweden, and Norway. Reviewers diagnosed the cases both before and after being provided with the biomarker results. The interobserver percent agreement and Cohen κ improved from 75.8% (κ=0.52, moderate) to 84% (κ=0.68, substantial) with inclusion of the biomarker panel. Agreement with the subsequent hysterectomy diagnosis also improved from 83.6% (κ=0.67) to 88.7% (κ=0.77). There was no statistical improvement between a reflex (84% agreement) and a reflective testing algorithm (82.9% agreement), suggesting that the selective use of biomarkers is appropriate. Difficult cases were almost exclusively high-grade tumors. Finally, a statistical model indicated that only P53 and DNA ploidy, in conjunction with an H&E review, had an impact on the decision to upgrade or downgrade cases.

No abstract

A 59‐year‐old man presented with clinical evidence of a primary tumor of the cauda equina region. It was well circumscribed and was completely removed by neurosurgery. Routine staining showed that it had structural similarities to an ependymoma, but immunohistochemistry with antisera to synaptophysin, NSE, chromogranin‐A and PGP 9.5 proved it to be a neuroendocrine tumor, i.e. a paraganglioma. We propose the use of endocrine markers in cases with tumors of the cauda equina to differentiate a paraganglioma from an ependymoma. Paragangliomas appear to have a better clinical outcome than ependymomas. Recurrence after surgery for a paraganglioma in the cauda equina region, especially if it is encapsulated, is rarely encountered.