Society of Toxicologic Pathology position on histopathology data collection and audit trail: compliance with 21 CFR parts 58 and 11.

The purpose of this paper is to discuss the requirement of the audit trail to track changes made to the histopathology data, in order to be compliant with the Code of Federal Regulations (CFR), Volume 21, for both Part 58 (Good Laboratory Practices [GLP]) and Part 11 (Electronic Records/Signatures).

Malignant fibrous histiocytoma. An unusual neoplasm of soft-tissue origin in the rat that is different from the human counterpart.

Malignant fibrous histiocytomas were found in eight F344 rats and four Sprague-Dawley rats. They appeared to originate in skin or peritoneum and to have metastasized to liver and lung. Tumor cells appeared to be histiocytic in the light microscopic studies and fibroblastic after ultrastructural evaluation.

Correlation between gross observations of tumors and neoplasms diagnosed microscopically in carcinogenesis bioassays in rats.

Microscopic diagnoses of spontaneous and induced neoplasms in F344 rats in two carcinogenesis bioassays were correlated with the gross observations made at the time of necropsy. The results for a negative and a positive compound with reference to carcinogenicity, indicate that of the gross descriptions indicative of tumors, 37 percent and 24 percent respectively, were not diagnosed as neoplasms microscopically. However, some of the gross lesions were diagnosed histologically as nonneoplastic lesions.