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Splenomegaly 937

DIAGNOSIS ○ Retroviral testing feline leukemia virus/ these infectious diseases (e.g., Babesia spp,
feline immunodeficiency virus (FeLV/FIV) hemotrophic Mycoplasma spp) are harder to
VetBooks.ir Diagnostic plan depends on other historical and • Advanced diagnostics for disease suspected ○ Splenectomy can predispose to certain Diseases and Disorders
Diagnostic Overview
○ Bartonella serology and PCR
clear after splenectomy.
○ Others as suggested by other findings
infections (e.g., Mycoplasma haemocanis).
exam findings but often includes abdominal
imaging. Radiographs are preferred for assess-
ing size of the spleen, whereas ultrasound is to cause splenomegaly: • Splenectomy can predispose to GDV.
Although controversial, gastropexy should
○ Immune-mediated disease (e.g., Coombs’
preferred for differentiating focal and diffuse test, flow cytometry) be considered at the time of splenectomy
enlargement and assessing splenic parenchyma. ○ Lymphoid neoplasia (e.g., PCR for antigen in selected patients (e.g., deep-chested dog
Minimal laboratory data may guide prioritiza- receptor rearrangement [PARR], flow breeds).
tion of differential diagnoses and aid in deter- cytometry)
mining whether the platelet count is adequate ○ Right heart failure (e.g., echocardiogram, Recommended Monitoring
to perform a fine-needle aspiration (FNA) of heartworm test) Monitor for coagulopathy, ventricular arrhyth-
the spleen (if appropriate). Diseases commonly ○ Extramedullary hematopoiesis (e.g., bone mias, and anemia requiring blood transfusion in
diagnosed by cytology with an ultrasound- marrow aspirate ± core biopsy) patients with HSA. Monitor severity of anemia
guided FNA sample include extramedullary • FNA (ultrasound guided): allows for identi- in patients with IMHA, ITP, and erythrocytic
hematopoiesis (EMH), lymphoma, mast cell fication of infiltrative neoplasia (lymphoma, infections.
neoplasia, and some infectious diseases (e.g., mast cell tumor) and some infectious diseases
histoplasmosis, cytauxzoonosis). (e.g., histoplasmosis). PROGNOSIS & OUTCOME
○ Not usually indicated for cavitated splenic
Differential Diagnosis mass due to risk of hemorrhage/splenic • Prognosis depends on the underlying disease
Enlargement of other abdominal organs can rupture and low diagnostic yield process resulting in splenomegaly.
be mistaken for splenomegaly. • Splenic biopsy (splenectomy or, less com- • Benign masses of the spleen generally carry
monly, incisional biopsy): histopathologic a good prognosis with removal (64% alive
Initial Database evaluation ± culture. at 1 year).
CBC:
• Nonregenerative anemia: bone marrow TREATMENT PEARLS & CONSIDERATIONS
infiltrative disease with secondary EMH
• Regenerative anemia: IMHA, splenic mass Treatment Overview Comments
hemorrhage/rupture, erythrocyte organisms Treatment is aimed at the underlying disease. • Degree of splenomegaly cannot be used to
(e.g., Babesia spp) Diffuse enlargement of the spleen is rarely an predict malignancy or likelihood of disease
• Thrombocytopenia: vector-borne disease, ITP, indication for splenectomy because it could recovery. Splenic hematoma can cause
platelet consumption, splenic sequestration worsen the clinical condition (e.g., Babesia spp, profound splenomegaly but is a benign
• Blood smear evaluation for RBC organisms, EMH). Most causes of diffuse splenomegaly condition.
spherocytosis (IMHA), schistocytosis (HSA) are treated medically. However, splenic torsion • If a systemic disease or drug is recognized
Chemistry panel: or focal enlargement (i.e., splenic mass) often as a likely cause of splenomegaly, specific
• Hypercalcemia: lymphoma, other neoplastic calls for complete (or sometimes partial) splenic sampling may not be indicated.
disease, fungal/granulomatous disease splenectomy. • Diffuse splenomegaly is rarely an indica-
• Hyperglobulinemia: neoplasia (multiple tion for splenectomy (splenic torsion is an
myeloma, lymphoma), feline infectious Acute General Treatment exception).
peritonitis (FIP), nonspecific inflammatory • Red blood cell (RBC) transfusion (packed • Ultrasound-guided FNA samples can provide
disease RBC or whole blood): sometimes indicated important cytologic evaluation of the spleen
Urinalysis: for hemoabdomen due to splenic mass but is not advised if cavitation is recognized.
• Bilirubinuria, hemoglobinuria: hemolysis hemorrhage/rupture or severe anemia • If the whole spleen is removed, the entire
Imaging: secondary to IMHA or ITP spleen should be submitted for histopatho-
• Abdominal radiographs: confirm spleno- • Splenectomy: patients with a bleeding splenic logic evaluation. Use adequate volume of
megaly and identify additional issues (e.g., mass benefit therapeutically and diagnosti- formalin for diagnostic submission, and slice
effusion, concurrent hepatomegaly) cally from prompt splenectomy. Patients can excised spleen to allow proper fixation.
• Abdominal ultrasound: diffuse or focal (i.e., stabilize on their own if the bleeding stops
mass) enlargement, echogenicity of spleen, and they reabsorb peritoneal hemorrhage. Prevention
metastatic disease or involvement of other • Antiarrhythmic agents (e.g., lidocaine 2 mg/ Tick prevention reduces the chance of vector-
abdominal organs (e.g., liver), vascular kg IV bolus): treatment of ventricular borne disease.
occlusion (splenic torsion, thrombosis) arrhythmias is indicated in patients with
• Thoracic radiographs: metastatic disease, ventricular tachycardia or frequent ventricular Technician Tips
right-sided cardiac enlargement ectopy (especially if resulting in hemody- Patients with splenic mass or undergoing sple-
• Advanced imaging of the abdomen (CT or namic instability). nectomy should be monitored by continuous
MRI): provides more detailed information electrocardiogram (p. 1096) for arrhythmia.
but costly and requires anesthesia/sedation Chronic Treatment
Chronic management is specific for the disease SUGGESTED READING
Advanced or Confirmatory Testing process resulting in splenomegaly. Argyle DJ, et al: Nonneoplastic diseases of the spleen.
Choice of tests determined by initial data: In Ettinger SJ, et al, editors: Textbook of veterinary
• Specific infectious disease testing, when Behavior/Exercise internal medicine, ed 8, St. Louis, 2017, Elsevier.
appropriate Animals with a splenic mass should be handled
○ Babesia spp polymerase chain reaction with caution to reduce the risk of rupture. AUTHOR: Laura A. Nafe, DVM, MS, DACVIM
(PCR) and serology EDITOR: Leah A. Cohn, DVM, PhD, DACVIM
○ Cytauxzoon felis PCR Possible Complications
○ Ehrlichia spp serology and/or PCR • The spleen has an important role in
○ Histoplasma capsulatum urine antigen controlling some infectious diseases, and

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