Page 510 - Feline diagnostic imaging

522 29 Hemolymphatic System

(a)

(b) (c)

Figure 29.28 Ultrasonography of splenic hemangiosarcoma. A 9-year-old cat was admitted for a recheck evaluation after removal of
cutaneous hemangiosarcoma one month earlier. (a) Ultrasonography showed multiple nodules throughout the spleen. The nodules
were hypoechoic or hypoechoic with a hyperechoic center (“target” lesion). Histopathology confirmed splenic hemangiosarcoma.
(b) Additional ultrasound image of the spleen. (c) Hypoechoic nodules were also seen in the liver. St, stomach.

Infarction typically causes hypoechoic or lacey lesions in complex echogenicity – there will be anechoic and hypo-
the spleen of dogs [31]. echoic areas intermingled with hyperechoic areas
Focal, anechoic lesions usually contain nonviscous fluid. because hemangiosarcomas tend to undergo various
Cysts classically have well‐defined margins and deep stages of hemorrhage and clotting. In dogs, large masses
acoustic enhancement. Acquired pseudocysts, possibly old without rupture were shown to be less likely to be malig -
hematomas, can have a similar appearance. Anechoic nant [33]. Warning signs of malignancy include hemor-
lesions can be associated with neoplasia so that surround- rhage in the abdomen, disruption of the splenic capsule,
ing tissue should be carefully analyzed for abnormalities. and evidence of spread to other organs including the
One type of focal lesion has been described as a “target” liver, heart, lungs, and muscle or bone. Radiographs and
lesion (Figure 29.28). This lesion has a hyperechoic center additional ultrasonography should be done to evaluate
and a hypoechoic periphery. In one study, this type of these organs, particularly the heart. Cardiac hemangio-
lesion in the spleen and liver of dogs and cats was shown to sarcoma is most common in the right atrium but can
have a higher potential for malignancy [32]. occur in other locations in the heart. Pericardial effusion
may also be present. Pulmonary nodules are usually
numerous, variably sized, and poorly defined fluid
29.5.5 Complex Sonographic Lesions
opacities. Hepatic hemangiosarcomas can present as
Hemangiosarcoma (Figure 29.28) occurs less commonly large masses similar to splenic masses or small nodules.
in cats than in dogs. Hemangiosarcomas usually have Metastatic peritoneal nodules can also occur. Blood in