Alimentary System
Salivary Gland, Duct - Dilation
Narrative
Comment:
Ductular dilation of salivary glands is typically more generalized (involving multiple ducts), and the ducts tend to have an irregular profile (Figure 1 and Figure 2), whereas salivary gland duct cysts tend to involve one or a few ducts and usually have a circular profile (see
). Ductular dilation is sometimes associated with squamous metaplasia of the duct epithelium. Ductular dilation and ductular cysts are not common in NTP rodent studies.
Recommendations:
Whenever present, ductular dilation should be diagnosed and graded based on the number of ducts involved and size of the dilated ducts. If squamous metaplasia of the ductal epithelium is present, it should be diagnosed and graded separately.
References:
Germann PG, Ockert D, Tuch K. 1995. Oropharyngeal granulomas and tracheal cartilage degeneration in Fischer-344 rats. Toxicol Pathol 23:349-355.
Abstract: https://www.ncbi.nlm.nih.gov/pubmed/7659957National Toxicology Program. 1989. NTP TR-350. Toxicology and Carcinogenesis Studies of Tribromomethane (Bromoform) (CAS No. 75-25-2) in Fe44/N Rats and B6C3F1 Mice (Gavage Studies). NTP, Research Triangle Park, NC.
Abstract: https://ntp.niehs.nih.gov/go/6961Neuenschwander SB, Elwell MR. 1990. Salivary glands. In: Pathology of the Fischer Rat (Boorman GA, Montgomery CA, MacKenzie WF, eds). Academic Press, San Diego, CA, 31-42.
Abstract: https://www.ncbi.nlm.nih.gov/nlmcatalog/9002563
Salivary gland, Duct - Dilation in a female F344/N rat from a chronic study. Multiple ducts in this gland are dilated (arrows).
All Images
Salivary gland, Duct - Dilation in a female F344/N rat from a chronic study. Multiple ducts in this gland are dilated (arrows).
Salivary gland, Duct - Dilation in a female F344/N rat from a chronic study (higher magnification of Figure 1). The dilated duct has an irregular profile and contains some debris.