Veterinary Diagnostic

Investigation and Consultation

Nov 12th, 2024

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Ultrasonographic liver nodules are more often benign lesions in dogs with hemoperitoneum secondary to splenic tumor rupture

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The use of abdominal ultrasonography is often included in the care of these patients. The purpose of this ultrasonography is both to determine the origin of the bleeding tumor and, more importantly, to look for the presence of possible metastasis within the abdomen. Specifically, the presence of liver or other intra-abdominal nodules on a preoperative abdominal ultrasonography may reasonably raise concerns for possible metastatic disease and may dissuade some owners from electing to go forward with treatment. Previous research investigating the prevalence of hepatic metastasis secondary to splenic hemangiosarcoma at the time of diagnosis is limited. Clendaniel et al observed an overall 37% prevalence of hepatic metastasis from splenic hemangiosarcoma, consistent with findings by Hammond and Pesillo-Crosby. Another study reported that the presence of nodules on both the spleen and liver indicated a 48% likelihood of a splenic hemangiosarcoma diagnosis. A retrospective study of 14 dogs with retroperitoneal sarcoma reported an overall prevalence of metastasis to be 29%. Nine of the dogs in that study had a diagnosis of retroperitoneal hemangiosarcoma, with 3 of those dogs having concurrent metastasis, resulting in a hemangiosarcoma-specific prevalence of 33%.

 

Recently we reported on a small cohort of dogs with splenic tumor rupture and found that only 33% of liver nodules found on preoperative ultrasonography were subsequently histologically confirmed to be metastatic hemangiosarcoma lesions. Accordingly, these preliminary data raise questions about the value of ultrasonography as a preoperative staging diagnostic for identifying potential metastatic disease in the liver. Furthermore, ultrasound failed to identify most omental metastases that were subsequently identified intraoperatively in this same cohort.

 

Based on these collective data, we were prompted to inquire whether relying solely on conventional abdominal ultrasonography as a method to detect the bleeding source and potential visceral metastasis is satisfactory for deciding to proceed with surgery. To address this query, we examined data obtained from a comprehensive prospective study (Ethos Precision Medicine Umbrella Study for Hemangiosarcoma [Ethos-PUSH]) involving dogs experiencing hemoperitoneum attributed to suspected splenic tumor rupture

 

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OBJECTIVE

To evaluate the reliability of preoperative abdominal ultrasonography as a staging tool for dogs with hemoperitoneum due to presumed splenic tumor rupture, focusing on the detection of metastatic lesions in the liver.

 

ANIMALS

99 dogs from 20 emergency and specialty hospitals across the US.

 

METHODS

Dogs with nontraumatic hemoperitoneum secondary to splenic tumor rupture were included. A post hoc analysis was conducted on data from a nationwide prospective trial investigating novel treatments for canine hemangiosarcoma. The accuracy of preoperative staging was assessed by comparing ultrasonographic findings with intraoperative observations and histologic findings.

 

RESULTS

On preoperative ultrasonography, there was a 20% incidence of liver lesions identified, with no association to liver lesions seen during operation. Notably, 22% of liver lesions observed during operation were missed on preoperative ultrasonography. The presence of liver lesions on preoperative ultrasonography was associated with a higher likelihood of a benign splenic tumor diagnosis. There was no association between the identification of liver lesions on preoperative ultrasonography and the presence of metastatic disease on liver biopsy, with a sensitivity and specificity of 19% and 82%, respectively. Additionally, ultrasound had low sensitivity in detecting intra-abdominal lesions beyond the liver and spleen, with 82% of these lesions missed preoperatively.

 

CLINICAL RELEVANCE

This study challenges conventional perceptions around the approach to staging in dogs with hemoperitoneum. These findings advocate for a reevaluation of the staging approach, with more comprehensive modalities like whole-body CT or MRI potentially being more warranted.