Page 1260 - Cote clinical veterinary advisor dogs and cats 4th

Mass, Splenic 631

○ Diffuse splenomegaly associated with 24 hours) and typically resolve after 1-5
immune-mediated disorders, may/may • Long-term follow-up depends on diagnosis
days.
VetBooks.ir ○ Splenectomy is contraindicated in cases (e.g., thoracic radiographs q 3 months to Diseases and Disorders
not help underlying disease process
monitor for pulmonary metastasis)
of babesiosis and other hematologic
infections.
PROGNOSIS & OUTCOME
Chronic Treatment
• Supportive care in the postoperative period • Prognosis varies with cause for malignant
○ Analgesia and nonmalignant causes of splenic mass.
○ Fluid therapy must replace blood volume • Hemangiosarcoma (most common malignant
that was present in the mass. splenic neoplasm in dogs); median survival
SPLENIC MASS The large splenic mass was removed ○ Transfusion therapy (p. 1169)
and diagnosed as benign nodular hyperplasia. Size time: 0-3 months with surgery alone, 4-8
and shape of the mass are not a substitute for ○ Treatment of cardiac arrhythmias (pp. months with surgery and chemotherapy
histopathologic diagnosis. 1033 and 1457) • Cats with systemic mastocytosis that undergo
• Adjunct chemotherapy for malignant splenectomy often have extended survival
neoplasia times and may be cured.
• Prognostic indicators: NOTE: these findings
shock with IV fluids and blood products as Drug Interactions are suspicious for but do not confirm a
needed. Immediate surgery is indicated for • Avoid acepromazine or other phenothiazine diagnosis. Only histopathologic evaluation of
patients with active hemorrhage if pressures tranquilizers before surgery. tissue can definitively differentiate malignant
cannot be stabilized or if blood products are ○ Causes splenic enlargement; may worsen and benign disease.
not available. bleeding and complicate removal ○ Preoperatively, dogs with anemia, nucle-
• Some causes of splenic mass are amenable to ○ Can cause hypotension through central ated RBCs, abnormal RBC morphology,
medical treatment (e.g., lymphoma, diffuse mechanisms and through alpha-adrenergic or splenic rupture are more likely to have
splenomegaly associated with congestion from actions; may progress to cardiovascular malignant splenic neoplasia.
right heart failure or from infectious [e.g., collapse ○ In one study, 50% of large incidentally
babesiosis, cytauxzoonosis] or inflammatory • Avoid phenylephrine unless splenic mass is discovered splenic masses in the absence
disease [e.g., immune-mediated hemolytic confirmed benign of hemoabdomen were benign.
anemia]). ○ Risk of seeding of tumor cells
PEARLS & CONSIDERATIONS
Acute General Treatment Possible Complications
• Initial stabilization for acute intraabdominal • Rupture of splenic mass Comments
hemorrhage ○ Hemoabdomen • In the dog, a splenic mass may be non-
○ IV fluid resuscitation (crystalloids ± ○ Hypotension neoplastic (e.g., hematoma) or may be a
colloids) ○ Hemorrhagic/hypovolemic shock benign (e.g., hemangioma) or malignant
○ Blood product transfusion if needed ○ Coagulation disorders (e.g., hemangiosarcoma) neoplasm, and the
(p. 1169) ○ Cardiovascular collapse and death entire mass and/or spleen should always be
○ Definitive surgical therapy is recom- • Intraoperative and postoperative complica- submitted for histopathologic exam.
mended after patient is stabilized. tions • Be sure to section (bread-loaf) large masses
○ Immediate surgery if patient cannot be ○ Hemorrhage into slices < 1-2 cm thick to allow appropri-
stabilized (i.e., massive, ongoing internal ○ Ventricular arrhythmias ate penetration of formalin.
hemorrhage) ○ Damage to blood supply of pancreas • It is impossible to differentiate splenic
• Treat coagulation disorders if prothrombin ○ Pancreatitis from traumatic handling of masses based on their gross appearance.
time/activated partial thromboplastin time pancreas Diagnosis is always based on histopathologi-
(PT/aPTT) significantly prolonged (> 2 × ○ Chronic anemia from loss of red cal exam.
normal) (p. 1325): blood cell reservoir and decreased hema- • Accelerated idioventricular rhythms do not
○ Fresh-frozen plasma, fresh whole blood topoiesis require treatment; however, monitor closely
• Correct/control ventricular arrhythmias. ○ Diminished immune function (especially because they can convert to ventricular
○ Correction of anemia/hypovolemia or vector-borne and fungal disease) tachycardia.
electrolyte abnormalities often resolves ○ Portal vein thrombosis (uncommon)
ventricular arrhythmias without antiar- ○ Gastric dilation/volvulus (uncommon); Technician Tips
rhythmic drugs. consider gastropexy in predisposed breeds • The volume lost by removal of large masses
○ Treat if arrhythmia persists and is patho- frequently causes postoperative hypovolemia.
logic (pp. 1033 and 1457). Recommended Monitoring Familiarity with the signs of hypovolemia is
• Complete splenectomy is necessary for • Standard postoperative patient monitoring imperative for postoperative management.
control of hemorrhage and definitive • Serial PCV and total protein (TP) to monitor • Be able to recognize accelerated idioven-
diagnosis by histology. for hemorrhage tricular rhythm, R-on-T complexes and
○ Partial splenectomy is not recommended • Heart rate, blood pressure, and urine output ventricular tachycardia to know when to
for splenic masses. to evaluate hydration status and restore alert the clinician for treatment of ventricular
○ Consider liver biopsy ± lymph node biopsy euvolemia arrhythmias (pp. 1033 and 1457).
for staging purposes. • ECG monitoring for cardiac arrhythmias
• Nonsurgically treated splenic masses ○ Continuous ECG for first 24 hours Client Education
○ Some neoplasms (e.g., lymphoma) treated postoperatively; spot checks thereafter • Bleeding splenic masses
with chemotherapy if no arrhythmias noted and/or prior ○ Two-thirds are malignant, and two-thirds
○ Diffuse metastatic disease (e.g., heman- arrhythmias resolving of those are hemangiosarcoma.
giosarcoma, histiocytic sarcoma): owner ○ Ventricular arrhythmias may develop in • Splenic masses may rupture and cause lethal
may elect palliative treatment only. first 3 days postoperatively (most within intraabdominal hemorrhage.

www.ExpertConsult.com