National Toxicology Program Satellite Symposium Research Articles

Proceedings of the 2022 National Toxicology Program Satellite Symposium.

The 2022 annual National Toxicology Program Satellite Symposium, entitled "Pathology Potpourri," was held in Austin, Texas at the Society of Toxicologic Pathology's 40th annual meeting during a half-day session on Sunday, June 19. 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 topics covered during the symposium included induced and spontaneous neoplastic and nonneoplastic lesions in the mouse lung, spontaneous lesions in the reproductive tract of a female cynomolgus macaque, induced vascular lesions in a mouse asthma model and interesting case studies in a rhesus macaque, dog and genetically engineered mouse model.

Proceedings of the 2019 National Toxicology Program Satellite Symposium.

The 2019 annual National Toxicology Program Satellite Symposium, entitled "Pathology Potpourri," was held in Raleigh, North Carolina, at the Society of Toxicologic Pathology's 38th 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 topics covered during the symposium included aging mouse lesions from various strains, as well as the following lesions from various rat strains: rete testis sperm granuloma/fibrosis, ovarian cystadenocarcinoma, retro-orbital schwannoma, periductal cholangiofibrosis of the liver and pancreas, pars distalis hypertrophy, chronic progressive nephropathy, and renal tubule regeneration. Other cases included polyovular follicles in young beagle dogs and a fungal blood smear contaminant. One series of cases challenged the audience to consider how immunohistochemistry may improve the diagnosis of some tumors. Interesting retinal lesions from a rhesus macaque emphasized the difficulty in determining the etiology of any particular retinal lesion due to the retina's similar response to vascular injury. Finally, a series of lesions from the International Harmonization of Nomenclature and Diagnostic Criteria Non-Rodent Fish Working Group were presented.

Proceedings of the 2018 National Toxicology Program Satellite Symposium

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 a Sprague Dawley 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 swith 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 zebra fish 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 2017 National Toxicology Program Satellite Symposium.

The 2017 annual National Toxicology Program Satellite Symposium, entitled "Pathology Potpourri," was held in Montreal, Quebec, Canada at the Society of Toxicologic Pathology's 36th 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 renal papillary degeneration in perinatally exposed animals, an atriocaval mesothelioma, an unusual presentation of an alveolar-bronchiolar carcinoma, a paraganglioma of the organ of Zuckerkandl (also called an extra-adrenal pheochromocytoma), the use of human muscle samples to illustrate the challenges of manual scoring of fluorescent staining, intertubular spermatocytic seminomas, medical device pathology assessment and discussion of the approval process, collagen-induced arthritis, incisor denticles, ameloblast degeneration and poorly mineralized enamel matrix, connective tissue paragangliomas, microcystin-LR toxicity, perivascular mast cells in the forebrain thalamus unrelated to treatment, and 2 cases that provided a review of the International Harmonization of Nomenclature and Diagnostic Criteria (INHAND) bone nomenclature and recommended application of the terminology in routine nonclinical toxicity studies.

Proceedings of the 2016 National Toxicology Program Satellite Symposium.

The 2016 annual National Toxicology Program Satellite Symposium, entitled "Pathology Potpourri" was held in San Diego, CA, at the Society of Toxicologic Pathology's (STP) 35th 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. Some lesions and topics covered during the symposium included malignant glioma and histiocytic sarcoma in the rodent brain; a new statistical method designed for histopathology data evaluation; uterine stromal/glandular polyp in a rat; malignant plasma cell tumor in a mouse brain; Schwann cell proliferative lesions in rat hearts; axillary schwannoma in a cat; necrosis and granulomatous inflammation in a rat brain; adenoma/carcinoma in a rat adrenal gland; hepatocyte maturation defect and liver/spleen hematopoietic defects in an embryonic mouse; distinguishing malignant glioma, malignant mixed glioma, and malignant oligodendroglioma in the rat; comparison of mammary gland whole mounts and histopathology from mice; and discussion of the International Harmonization of Nomenclature and Diagnostic Criteria collaborations.

Proceedings of the 2015 National Toxicology Program Satellite Symposium.

The 2015 Annual National Toxicology Program Satellite Symposium, entitled "Pathology Potpourri" was held in Minneapolis, Minnesota, at the American College of Veterinary Pathologists/American Society for Veterinary Clinical Pathology/Society of Toxicologic Pathology combined meeting. The goal of this symposium is to present and discuss diagnostic pathology challenges or nomenclature issues. Because of the combined meeting, both laboratory and domestic animal cases were presented. This article presents summaries of the speakers' talks, including challenging diagnostic cases or nomenclature issues that were presented, along with select images that were used for audience voting and discussion. Some lesions and topics covered during the symposium included hepatocellular lesions, a proposed harmonized diagnostic approach to rat cardiomyopathy, crop milk in a bird, avian feeding accoutrement, heat exchanger in a tuna, metastasis of a tobacco carcinogen-induced pulmonary carcinoma, neurocytoma in a rat, pituicytoma in a rat, rodent mammary gland whole mounts, dog and rat alveolar macrophage ultrastructure, dog and rat pulmonary phospholipidosis, alveolar macrophage aggregation in a dog, degenerating yeast in a cat liver aspirate, myeloid leukemia in lymph node aspirates from a dog, Trypanosoma cruzi in a dog, solanum toxicity in a cow, bovine astrovirus, malignant microglial tumor, and nomenclature challenges from the Special Senses International Harmonization of Nomenclature and Diagnostic Criteria Organ Working Group.

A Monograph on Histomorphologic Evaluation of Lymphoid Organs

Shortly after the 2005 publication of the “Society of Toxicologic Pathology (STP) Position Paper on Best Practice Guidelines for the Routine Pathology Evaluation of the Immune System” (Haley et al., 2005), the National Toxicology Program (NTP) Satellite Symposium that preceded the 2005 annual STP meeting provided an interactive forum on this topic. Using specific examples of normal and abnormal lymphoid tissue histology, both during and after the NTP Satellite Symposium, it became apparent that a set of specific examples to illustrate the STP position paper would be useful to the toxicologic pathology scientific community. The present Monograph on the Histomorphologic Evaluation of Lymphoid Organs represents that endeavor. In the process of assembling the photomicrographs to support the STP Best Practices position paper, we realized that an illustrated review of normal structure, function, and histology of lymphoid organs as well as representative examples of common spontaneous and treatment-related lesions would provide useful background reference material. This monograph consists of peer-reviewed papers covering normal structure, function, pathology, and enhanced histopathology for lymph nodes, thymus, bone marrow, spleen, and mucosa-associated lymphoid tissues. In addition there is a paper on the immunohistochemistry of lymphoid organs. Papers dealing with enhanced histopathology are grouped separately in this monograph. Hopefully, topics covered will serve to bring focus to some relevant issues such as the distinction between thymic atrophy and physiological involution and assessment of direct immunomodulatory effects versus effects secondary to stress. We have not covered methods related to collection, processing, sectioning, and staining of lymphoid tissues or recommended a uniform grading scheme for severity of tissue alterations. The monograph emphasis is on rodent lesions with occasional addition of canine and nonhuman primate examples and is intended to be a guide and atlas for the general practicing toxicologic pathologist. All images are from hematoxylin and eosin-stained slides unless otherwise noted in the legend. The majority of images are produced in grayscale to maintain reasonable publication costs. All images are available in color on a CD-ROM inserted into this Monograph issue of Toxicologic Pathology. The images on the CD are of suitable resolution for teaching purposes. The occasional redundancy between papers and between the text and legends, plus some duplication of photomicrographs is a deliberate attempt to have individual papers as well as the enclosed CD of images be sufficiently comprehensive to stand-alone as a definitive resource. There was also