Proceedings of the 2018 National Toxicology Program Satellite Symposium

Abstract

The 2018 annual National Toxicology Program Satellite Symposium, entitled “Pathology Potpourri,” was held in Indianapolis, Indiana at the Society of Toxicologic Pathology’s 37th annual meeting. The goal of this symposium was to present and discuss challenging diagnostic pathology and/or nomenclature issues. This article presents summaries of the speakers’ talks along with select images that were used by the audience for voting and discussion. Various lesions and other topics covered during the symposium included seminiferous tubule dysgenesis in rats, ameloblast and odontoblast degeneration/necrosis in an SD rat, intestinal leiomyositis in a beagle dog, gallbladder mucinous hyperplasia, focus of hepatocellular alteration and bile duct alteration in otters, renal tubule cytoplasmic vacuolation with basophilic granules in mice treated with antisense oligonucleotide therapy, a uterine choriocarcinoma in a rhesus macaque and rete ovarii proliferative ovarian lesions in various aged rat strains. One particularly provocative lesion was a malignant neoplastic proliferation in the renal pelvic region of a cynomolgus macaque from a 21-day study. Additional challenging lesions included thyroid proliferative lesions in Zebrafish and gross findings in fish larvae during routine chemical screening. The Rabbit and Minipig International Harmonization of Nomenclature and Diagnostic Criteria Organ Working Groups also presented a series of challenging lesions.

Proceedings of the 2019 National Toxicology Program Satellite Symposium

“…Therefore, it appears that these lesions often occur together. For a review of testicular dysgenesis, please see the proceedings from the 2018 NTP Satellite Symposium, 6 where Dr Cynthia Willson presented those lesions, or the Barlow et al article. 5…”

Phthalate Toxicity in Rats and Its Relation to Testicular Dysgenesis Syndrome in Humans

“…16,40 In the soon to be published US NTP studies of DBP and DEHP that included exposure beginning on gestation day 6, 18% or 20% of male rats exposed to 10,000 ppm of DBP or DEHP, respectively, had seminiferous tubule dysgenesis. 36,41 The dysgenesis lesions were typically seen in one of three sections of the testis, usually the section also containing the rete testis. 24,41 Testes containing seminiferous tubule dysgenesis lesions from the 2-year-old rats exposed in utero and throughout life to DBP also commonly had germinal epithelium atrophy, interstitial edema, and an unusual fibrosis and/or sperm granuloma in the rete testis region, which has been previously reported.…”

“…36,41 The dysgenesis lesions were typically seen in one of three sections of the testis, usually the section also containing the rete testis. 24,41 Testes containing seminiferous tubule dysgenesis lesions from the 2-year-old rats exposed in utero and throughout life to DBP also commonly had germinal epithelium atrophy, interstitial edema, and an unusual fibrosis and/or sperm granuloma in the rete testis region, which has been previously reported. 24,42 Interestingly, similar focal histological testicular dysgenesis is also reported in testicular biopsies from patients with TDS disorders, including infertile men, men with cryptorchidism, and in the contralateral or ipsilateral testis in men with TGCT (in either scrotal or cryptorchid testes; Table 1).…”