A Spontaneous Seminal Vesicle Adenocarcinoma in an Aged F344 Rat

Abstract

P rark seminal vesicle adenocarcinoma was found in a 109-wk-old Fischer 344 (F344) rat. At necropsy, the right seminal vesicle was enlarged, containing a 15-X 18-Xl8-mm mass. The neoplasm occupied almost the entire seminal vesicle lumen and consisted of epithelial cells arranged in papillary, glandular, and solid patterns. Tumor cells were larger than their normal counterparts in the seminal vesicles and had round nuclei and abundant cytoplasm. Clusters of macrophagelike cells with less abundant cytoplasm and indented nuclei were apparent in the lumina of the glandular structures formed by the tumor cells. No metastasis to other tissues or organs was observed. Immunohistochemically, tumor cells were positive for keratin and S-100, and the macrophagelike cells bound antibodies against vimentin and ED-I. Ultrastructurally, the tumor cells exhibited many small secretory granules, some microvilli, and intercellular junctions. The macrophagelike cells, in contrast, were characterized by lysosomes and abundant rough endoplasmic reticulum. Therefore, a diagnosis of seminal vesicle adenocarcinoma with intraluminal macrophage infiltration was made. This is the first case report of such a seminal vesicle tumor in an F344 rat.Keyvords. Neoplasm; keratin; vimentin; S-100; ED-I; PCNA Spontaneous neoplasms of the seminal vesicles are extremely rare in laboratory and domestic animals and in humans. Even in rats that have a high incidence of spontaneous prostate tumors, almost no proliferative lesions develop in the seminal vesicles. Based on the records for 51,230 male Fischer 344 (F344) rats used in more than 300 long-term toxicity and carcinogenicity studies in the National Toxicology Program, an incidence of only 0.004% was reported for seminal vesicle adenomas; only 2 lesions were found (6). As part of background data for life span studies of male F344 rats, 1 seminal vesicle adenocarcinoma (0.19%) was found in 529 control males (9). There are a small number of reports of spontaneous seminal vesicle tumors in the rat, but most of these reports did not give detailed descriptions (2, 3, 10) and no ultrastructural observations have been documented. Neoplasms of the seminal vesicle, however, can be experimentally induced in rats by several agents such as Nnitrosobis(2-oxopropyl)amine, N-methylnitrosourea, and irradiation (5, 7, 8).In this report, we describe 1 case of a spontaneous seminal vesicle adenocarcinoma in an aged F344 rat maintained as a control for a carcinogenicity study. This is the first such case reported for F344 rats.The tumor was found in a 109-wk-old male F344/' DuCrj strain rat (Charles River Japan, Kanagawa), one of 150 controls for each sex in a 2-yr carcinogenicity study. The rat was housed in a plastic cage with woodchip bedding in an air-conditioned barrier-system animal FIG. 1 .-Seminal vesicle adenocarcinoma filling the seminal vesicle lumen of a rat. Note the continuation from the normal glandular epithelium of the seminal vesicle to the tumor (arrows) and the compression of the coagulating ...

A Retrospective Analysis of Background Lesions and Tissue Accountability for Male Accessory Sex Organs in Fischer-344 Rats

“…This interstrain susceptibility was suggested to be related to a possible decreased sensitivity of androgen receptors in F-344 rats (44). Epithelial hyperplasia and adenoma, as well as adenocarcinoma, are rarely reported in the seminal vesicle in the F-344 rat (22,30,46); similar ndings were observed in the present investigation. Spontaneous proliferative lesions including hyperplasia and adenoma have not been reported in the ampullary gland in rats (7).…”

Squamous Cell Carcinoma of the Seminal Vesicle from Zinner Syndrome: A Case Report and Review of Literature

“…Although the specimen displayed some immunoactivity for vimentin ( Fig. 3E ), the staining was positive in macrophages, as reported in murine seminal vesicle carcinoma [ 5 ]. Histochemical studies (periodic acid–Schiff [PAS] and mucicarmine) were positive for mucin ( Fig.…”

Proliferative and Nonproliferative Lesions of the Rat and Mouse Male Reproductive System

“…Cribriform adenocarcinoma of the ventral prostate and coagulating gland may lack clear invasive growth but is characterized by marked cellular and nuclear polymorphism. Adenocarcinoma of the prostate and seminal vesicle are rare spontaneous tumors in most strains of rat and mouse (Bosland 1987a, 1987b; Shoda et al 1998). They have been observed in some strains, notably in ACI/segHapBR rats (Oshima et al 1985; Ward et al 1983).…”

“…The predominant growth pattern of the induced lesion was described as microglandular to tubular; cribriform and comedo patterns were not found. Spontaneous proliferative lesions of prostate lobes in mice are uncommon but some transgenic mice show a high incidence (Reznik et al 1981;Shappell et al 2004;Suttie et al 2003 (Bosland 1987a(Bosland , 1987bShoda et al 1998). They have been observed in some strains, notably in ACI/ segHapBR rats (Oshima et al 1985;Ward et al 1983).…”