Page 1411 - Small Animal Internal Medicine, 6th Edition

CHAPTER 86 Combined Cytopenias and Leukoerythroblastosis 1383

evaluation of the cell factory is logical if no evidence of RBC
BOX 86.2 regeneration in the blood smear or CBC exists (see Chapter
VetBooks.ir Causes of Leukoerythroblastosis in Dogs and Cats 82). Therefore BM aspiration and, ideally, BM core biopsy to
obtain specimens for histopathologic studies should be per-
EMH*
except for dogs with highly likely or confirmed Evans syn-
Immune hemolytic anemia formed in all dogs and cats with combined cytopenias,
Blood loss anemia drome and dogs and cats with DIC; that is, the anemia is
Sepsis regenerative, so it is assumed that the factory is working
DIC properly. Algorithms for the evaluation of BM findings in
Chronic hypoxia (i.e., congestive heart failure) dogs and cats with bicytopenia and pancytopenia are shown
Neoplasia in Figs. 86.1 and 86.2. In private practice, obtaining a BM
Hemangiosarcoma
Lymphoma aspirate is usually easier; BM core biopsies are usually per-
Leukemias formed at specialty practices.
Multiple myeloma A BM evaluation should also be part of the clinical
Malignant histiocytosis workup in animals with LERs to determine whether the
Other immature WBCs and RBCs in the circulation are secondary
Diabetes mellitus to a primary BM disorder or a disorder such as EMH.
Hyperthyroidism Because abdominal neoplasms, particularly hemangiosar-
Hyperadrenocorticism coma, are commonly associated with LERs in dogs, abdomi-
Splenectomy nal ultrasonography should be done. If diffuse splenomegaly
is detected, percutaneous fine-needle aspiration of the spleen
Note: Entries in boldface are common causes; entries in italics
are relatively common causes; entries in regular typeface are should be performed. If splenic or hepatic masses or both
uncommon causes. are present, the patient should be evaluated as described in
DIC, Disseminated intravascular coagulation; EMH, extramedullary Chapter 78.
hematopoiesis; LER, leukoerythroblastic reaction. Abrams-Ogg et al. (2012) evaluated the use of a 15-
*Hematopoiesis may play a role in the pathogenesis of the LER in gauge needle and power driver in comparison to a standard
several of the disorders mentioned in the text.

CELLULAR

Normal/Hyperplastic Dysplastic Neoplastic

MDS HL
Splenomegaly Normal neoplasm
(FNA) spleen
Metastatic
neoplasm
EMH Neoplasia RE Immune-mediated
hyperplasia

Disorders in
release Hypersplenism Drug-induced

Peripheral
destruction

FIG 86.1
Algorithm for the diagnosis of a pancytopenic animal with hypercellular bone marrow.
EMH, Extramedullary hematopoiesis; FNA, fine-needle aspiration; HL, hemolymphatic;
MDS, myelodysplastic syndrome; RE, reticuloendothelium. Orange boxes indicate final
diagnoses.