High-frequency ultrasound of Peyer’s patches in the small intestine of young cats

Abstract

Presumed normal lymphatic tissue in the small intestinal submucosa can be seen with high-frequency ultrasound and is a common finding in young cats.

Ex Vivo Correlation of Ultrasonographic Small Intestinal Wall Layering With Histology in Dogs

“…In our study, in the ileal samples where this line was observed, there was no evidence of dilated lymphatic vessels or mucosal fibrosis histologically and only the enlarged submucosal lymphoid follicles (Peyer's patches) differed from the other intestinal samples lacking this hyperechoic thin mucosal line. Our finding is similar to a recent study in cats, reporting an asymmetrically positioned hypoechoic extra layer in the submucosa of the distal jejunum and ileum (separated from the mucosa by a thin hyperechoic line identical to the one observed in our study) using high‐frequency ultrasound, representing asymmetrically positioned normal lymphatic tissue (Peyer's patches) in the lamina propria and submucosa histologically . The difference of distribution of this line between our study (circumferential) and the aforementioned feline study may be due to the difference of distribution of the lymphoid tissue in these two species, more circumferential in the canine ileum and antimesenteric in cats .…”

“…Our finding is similar to a recent study in cats, reporting an asymmetrically positioned hypoechoic extra layer in the submucosa of the distal jejunum and ileum (separated from the mucosa by a thin hyperechoic line identical to the one observed in our study) using high‐frequency ultrasound, representing asymmetrically positioned normal lymphatic tissue (Peyer's patches) in the lamina propria and submucosa histologically . The difference of distribution of this line between our study (circumferential) and the aforementioned feline study may be due to the difference of distribution of the lymphoid tissue in these two species, more circumferential in the canine ileum and antimesenteric in cats . In dogs, a total of 26–29 Peyer's patches are described, with two different types reported, depending on their location .…”

“…Due to the lack of extensive history and blood work in the dogs included in this study, we cannot definitively conclude that these ultrasonographic findings were clinically nonsignificant. However, due to the minor histological changes associated with them, their high prevalence, the recent literature describing them as incidental findings, and the fact that most of these findings are commonly observed in a clinical setting at our hospital, in healthy dogs as well, it should also be considered that they could merely be associated with improved ultrasonographic transducer technology.…”

“…Mild lymphoid hyperplasia likely represents a response to nonsignificant immune stimulus; therefore, the significance of this line, if observed ultrasonographically in clinical cases, would be uncertain. Its visualization in cats has been considered a nonsignificant ultrasonographic finding …”

Feline abdominal ultrasonography: What’s normal? What’s abnormal? The normal gastrointestinal tract

“…An additional, asymmetrically positioned, hypoechoic layer of around 1 mm thickness within the submucosa of the feline distal jejunum and ileum is often visible when using high frequency ultrasound(Figure 8) 12. In some cats, the extra layer may have a lobulated appearance owing to the presence of multiple separate rounded hypoechoic structures located adjacent to each other.…”