Small Animal Radiology and Ultrasound: A Diagnostic Atlas and Text

452 Small Animal Radiolo g y and Ultrasono graphy
Fig. 3-271 Transverse sonograms of
the spleen of a 9-year-old female
Vizsla with a history of acute collapse
associated with thrombocytopenia
and mild anemia. There is a
hypoechoic round mass associated
with the tail of the spleen (open
arrows) (A). There is a hyperechoic
lesion adjacent to the splenic vein
(arrows) (B and D). An additional
small hypoechoic mass can be identified
(closed arrow) (C). These
hypoechoic lesions could be tumors
or areas of nodular hyperplasia. The
position of the hyperechoic lesion
adjacent to the splenic vein identifies
it as an area of infolding of fat at the
splenic hilus. Diagnosis: Nodular
hyperplasia.
A
B
C
D
Fig. 3-272 A 10-year-old neutered male German
Shorthaired Pointer with vomiting and a tense abdomen.
A and B, Radiographic findings include a midventral
soft-tissue intraperitoneal mass. C, Ultrasonographic
findings include an infiltrative, mixed echo mass (M) in
the spleen (S) with no liver or other abdominal abnormalities
except some mildly complex abdominal fluid.
Diagnosis: Leiomyosarcoma.
Continued
A
the splenic contour, or a diffuse hypoechoic or heteroechoic coarse pattern without marginal
deformity (Fig. 3-273). 902
A B D O M I N A L LY M P H N O D E S
The remainder of the intraabdominal hemolymphatic system is composed of various lymphatic
vessels and lymph nodes. One group is clustered around the mesenteric root ventral
to L2. These rarely are seen radiographically unless they are severely enlarged (Fig. 3-274).
The other major group constitutes the sublumbar lymph nodes: the external iliac, internal
iliac, and coccygeal lymph nodes. These lymph nodes are located ventral to the caudal lumbar
vertebrae and extend into the pelvic canal. Enlargement of these lymph nodes produces
an increased density dorsal to the colon, which alters the normal smooth contour of the
sublumbar muscles. There may be ventral colonic displacement, and in extreme cases the