The Case: Splenic Mass(es)

Presentation

An 8-year-old neutered male German shepherd was presented with a chief complaint of lethargy.

He had been eating and drinking well and his owners had noticed no abnormalities with urination or defecation. This morning he ate breakfast and lunch with a normal appetite, then was let outside with his housemate in the early afternoon. When the patient came back inside, he was unable to get comfortable and was salivating. The owner stated that there is no pest bait or other toxins (eg, mushrooms, etc) on the property. The patient has a history of subdermal cysts and treatment for ocular discharge but is otherwise healthy.

Physical Examination

• Bright, alert, and responsive

• Weight: 33 kg

• Temperature: 100.8⁰F

• Heart Rate: 140 bpm

• Respiratory Rate: Panting

• Mucous Membranes: Pale pink, slightly tacky

• Capillary Refill Time: <2 seconds  

• Hydration: Normal

• Eyes/Ears/Nose/Throat: Eyes clear OU

• Integument: Multiple subdermal cysts, hair coat in good condition

• Musculoskeletal: No significant findings, ambulatory ×4

• Cardiovascular: No murmurs or cardiac arrhythmias auscultated

• Respiration: Eupneic with normal bronchovesicular sounds in all lung fields

• Abdomen: No pain noted on palpation, fluid wave present

• Neurologic:  Normal findings

• Lymph Nodes:  Within normal limits (<2 cm)

Related Article: Top 5 Emergencies Requiring Anesthesia

Diagnostics

• Blood Gases/Electrolytes: Lactate 4.5 mmol/L (range, 0.6–2.9), all other values within normal limits

• Packed Cell Volume/Total Protein: 41% /5.4 g/dL (ranges, 33–58%/5.0–7.4)

• FAST* Scan: Free fluid was observed.

• Abdominal Ultrasound: Liver appeared normal in size and echotexture. Cranial aspect of the spleen was unremarkable in echotexture but small in size; a large, poorly defined mass appeared to extend from the body and/or tail. The mass was surrounded by mesentery and the colon was ventral to a portion of it, making it appear indistinct. Margins of the mass were somewhat irregular. Nodular appearance along the peripheral areas of the mass could have been separate masses, hematomas, or projections from the mass.  

• Abdominocentesis: Sanguinous fluid

• Packed Cell Volume/Total Protein of abdominal fluid: 35%/3 g/dL (ranges, 33–58% /5.0–7.4)

• Thoracic Radiographs: No obvious metastatic disease present, cardiovascular/pulmonary structures appeared normal.

*Focused assessment with sonography in trauma

Treatment

The results of the FAST scan and abdominocentesis were discussed with the owner and the differentials for a hemoabdomen were explained.

• Abdominal ultrasound was performed. The results showed an actively bleeding splenic mass; multiple masses potentially present. A quick scan of the heart showed no pericardial effusion.

• Surgery was advised with 3-view thoracic radiographs for a thorough metastasis check. The owners consented and radiographs were performed. Radiologist’s final review was pending at time of surgery. Splenectomy was performed and a liter of blood was removed from the abdomen. Patient recovered well in ICU with telemetry and PCV/TP monitoring (stabilized at 24%/4.2 g/dL) throughout the night.  A single short-lived period of ventricular tachycardia occurred and did not require treatment.

Related Article: Treatment of Acute Hemoabdomen in a Dog

Supportive Treatment

• Hetastarch: 27 mL/hr

• Lactated Ringer’s Solution: 75 mL/hr

• Fentanyl: 2 μg/kg/hr

Outcome

• ICU monitoring was continued overnight. The patient remained stable, with one episode of tachycardia the next day. He ate well and urinated regularly.

• Fentanyl was discontinued early in the afternoon and tramadol (4 mg/kg q8h PO) was instituted.

• Final radiologist report noted pulmonary nodules highly suspicious of metastasis.  

• The owners declined an oncology referral and agreed to monitor the patient closely for signs of decompensation at home.  

• He was euthanized a month later.

The Generalist’s Opinion

Barak Benaryeh, DVM, DABVP

Hemoabdomen is an occasional presentation in every general practice. The major concerns include stabilizing the patient, identifying the underlying cause, and recommending the appropriate course of action. In this case the underlying cause was appropriately and quickly identified and supportive care for the patient was initiated. The misstep was in the workup and subsequent information given to the owners.

Neoplastic Considerations

Reported incidence rates of neoplasia in dogs presenting with a splenic mass have varied over the years. Recent studies have noted that approximately 50% of splenic masses are neoplastic and, of those, approximately three fourths are hemangiosarcomas.^1,2 The clinicians in this case performed the appropriate diagnostics to identify metastatic disease. Thoracic radiographs (presumably a 3-view screen) and abdominal ultrasound including a screening of the right atrium were performed. These tests cover the common sites of metastasis, which include abdominal organs (mainly the liver) and lungs. A metastatic lesion in the lungs needs to be approximately 4 to 5 mm to show up radiographically.³ Lesions this small can be missed and a review by a radiologist, if available, is always helpful. Overlooking the metastatic lesions in the lungs was unfortunate; hemangiosarcoma that has metastasized carries a grave prognosis. It is likely that the choice would have been made not to carry through with surgery had the lesions been noted.

These owners chose not to follow up with chemotherapy. Hemangiosarcomas have a limited response to chemotherapy⁴ in general, and with metastases the benefits would be minimal. It’s important for any practitioner to have a working knowledge of available advanced therapeutics and prognoses.

Splenectomy

Perioperative mortality rates for dogs undergoing splenectomy have been reported at 7.6%.¹ Factors that affect surgical outcome include initial hematocrit, heart arrhythmias, changes in lactate, blood pressure, and concurrent health issues. This patient was supported with crystalloids and colloids and monitoring was performed for any electrocardiographic abnormalities. There was no mention of blood pressure being measured prior to surgery. Dogs with a hemoabdomen tend to be hypovolemic and continued blood loss is a major concern. Monitoring and maintaining an appropriate blood pressure is part of targeted therapy.

The patient made it through surgery and the owners had a month to spend with their pet. This part of the case was successful. We all miss the occasional lesion on a radiograph or a diagnosis may elude us. It’s important to stay sharp and current and then forgive ourselves and our colleagues when the occasional error happens.

Related Article: Total Splenectomy

The Specialist’s Opinion

Elisa M. Mazzaferro, MS, DVM, PhD, DACVECC

I applaud the authors submitting this case and the fact that the patient recovered well from a common and sometimes challenging surgery. I do, however, have some concerns about details that may have been inadvertently left out of the discussion. I suspect that many may have been considered and perhaps performed at the time that the animal was presented and treated.

Physical Examination

During the physical examination, a heart rate of 140 with pale mucous membranes and a palpable fluid wave in the abdomen raises the concern of hemoabdomen. The patient is tachycardic, but there is no mention of pulse quality or distal limb perfusion, which would help assess the degree of compensatory versus decompensatory hypovolemic shock. In addition, the patient was hyperlactatemic, which could be secondary to sepsis or hypoperfusion. With these factors in mind, I would strongly recommend measuring blood pressure and titrating intravenous fluid therapy to restore blood pressure/perfusion.

Fluid Therapy

There is no mention of intravenous fluid therapy prior to anesthesia and surgery. In cases of hemoabdomen of any cause, a preference is to implement goal-directed therapy and to titrate a combination of crystalloids and colloids to a specific blood pressure. Hypotensive resuscitation is one consideration, in which intravenous fluids are not administered and hypotension is allowed until the cause of bleeding has been surgically repaired. This concept has fallen out of favor owing to risk for organ damage secondary to hypoperfusion. Goal-directed, small-volume resuscitation should be implemented, with boluses of isotonic crystalloid solutions (0.9% NaCl, Plasmalyte-A, Normosol-R) in 10 mL/kg increments and colloids such as hydroxyethyl starch (5 mL/kg incremental boluses), to a blood pressure of 100 mmHg systolic, at least 40 mmHg diastolic, and a mean arterial pressure of 60 mmHg.

Related Article: Blood Transfusion Basics

Anesthesia

The report does not describe the type of anesthesia and anesthetic monitoring, whether the patient was hypotensive intra-operatively, or what type of monitoring was performed postoperatively. This omission is concerning, as some anesthesia drugs such as propofol, acepromazine, and gases can cause vasodilation and result in hypotension, particularly in a hypovolemic patient. In addition, balanced anesthetic protocols, such as a combination of a benzodiazepine with either fentanyl, small doses of propofol, or etomidate, are safe and can decrease the amount of drugs used. Intra-operatively, use of constant rate infusions of a benzodiazepine along with fentanyl, in addition to an epidural, also can decrease the amount of gas anesthesia required. Anesthetic plans and fluid therapy protocols for the emergent patient are of paramount importance to the outcome in any critical surgical patient.

Metastasis

The final major concern in this case discussion is the lack of identification of pulmonary metastatic nodules prior to surgery. Depending on the size of the nodules, a thoracic focused assessment using sonography for trauma (TFAST) could have been performed to evaluate for pleural effusion and pulmonary nodules. I applaud the authors for performing a cursory pericardial ultrasound to evaluate for pericardial effusion. If a splenic mass with hemoabdomen is found in a canine patient by ultrasound, client discussion should include that in approximately 1/3 of cases the lesion will be benign and more than 2/3 will be cancerous.¹ Of those masses that are malignant, the majority are hemangiosarcoma, with a median survival of 5 to 6 months with chemotherapy and only 3 months without chemotherapy.¹ Identification of the pulmonary nodules prior to surgery may have influenced the client’s decision as to whether or not to proceed with surgery.