Validation of digital pathology imaging for primary histopathological diagnosis.

AIMS: Digital pathology (DP) offers advantages over glass slide microscopy (GS), but data demonstrating a statistically valid equivalent (i.e. non-inferior) performance of DP against GS are required to permit its use in diagnosis. The aim of this study is to provide evidence of non-inferiority. METHODS AND RESULTS: Seventeen pathologists re-reported 3017 cases by DP. Of these, 1009 were re-reported by the same pathologist, and 2008 by a different pathologist. Re-examination of 10 138 scanned slides (2.22 terabytes) produced 72 variances between GS and DP reports, including 21 clinically significant variances. Ground truth lay with GS in 12 cases and with DP in nine cases. These results are within the 95% confidence interval for existing intraobserver and interobserver variability, proving that DP is non-inferior to GS. In three cases, the digital platform was deemed to be responsible for the variance, including a gastric biopsy, where Helicobacter pylori only became visible on slides scanned at the ×60 setting, and a bronchial biopsy and penile biopsy, where dysplasia was reported on DP but was not present on GS. CONCLUSIONS: This is one of the largest studies proving that DP is equivalent to GS for the diagnosis of histopathology specimens. Error rates are similar in both platforms, although some problems e.g. detection of bacteria, are predictable.

A case of recurrent mesocolon myxoid liposarcoma and review of the literature.

Background. Liposarcoma is the second most common soft tissue sarcoma affecting predominantly the retroperitoneal space and extremities. Mesenteric liposarcoma is uncommon and occurs in the small bowel mesentery. In this paper we report the case of a recurrent mesocolon myxoid liposarcoma manifesting 6 years from the initial right hemicolectomy for the primary tumour. Case Report. A 41-year-old female presented with a 4-day history of signs and symptoms indicative of small bowel obstruction, subsequently confirmed on plain abdominal X-ray. In 2006 she underwent a right hemicolectomy for a myxoid liposarcoma of the mesentery. The patient was initially managed conservatively; however she showed no signs of improvement and was taken to theatre for an exploratory laparotomy and division of adhesional bands. During this procedure an incidental finding of a dark purple, smooth pelvic mass was identified with similar macroscopic appearance to that of splenic tissue. Histological examination revealed a recurrent mesocolon myxoid liposarcoma. Conclusion. Mesocolon myxoid liposarcoma is a rare soft tissue neoplastic pathology and carries a high risk of recurrence. Therefore, a symptomatic patient with a previous history of primary liposarcoma excision should be treated with a high index of suspicion and a longer period of followup should be considered.

Carcinosarcoma of the biliary tract: two case reports and a review of the literature.

Carcinosarcoma of the biliary tract is extremely rare. Little is known about the natural course of these tumours, or the best available treatment. We present two cases of carcinosarcoma of the biliary tract, one of the gall bladder and one of the common bile duct, followed by a review of the literature.