Hemtopoietic Flashcards
Where do hematopoietic cells originate in the embryo before moving to the liver, spleen and bone marrow?
Yolk sac
What species does not release reticulocytes into the blood, even in times of high demand?
Equines
This bone marrow aspirate shows both early and late stage erythroid and myeloid cells. Is this a sample from healthy or pathologic bone marrow?
Healthy
When hematopoiesis is stimulated by cytokines, hormones, or growth factors, mature cells are released into the blood. Under what circumstances will we see immature cells released?
Bone marrow stress or disease
What blood test results will indicate examination of a bone marrow aspirate?
Unexplained cytopenias
Maturation defects/morphologic abnormalities
Myeloproliferative/Lymphoproliferative disease
Potential metastatic malignancies
T/F: A sample of bone marrow taken anywhere in the body is representative of the marrow as a whole.
TRUE
The bone marrow responds as a single tissue unit
A bone marrow core biopsy from a young cat, showing a megakaryocyte and adipose tissue. Who would you send this to for evaluation?
Morphologic pathologist
Diagnose this bone marrow of a neonatal calf.
Normal, hematopoietically active
Diagnose this bone marrow from a 13 day old foal.
Normal, hematopoietically active
Diagnose this bone marrow from a 2 month old calf.
Normal.
Yellow, butter-like marrow begins to replace red marrow as the calf ages. It serves as fat storage. The yellow color comes from carotenoids.
Diagnose this bone marrow from a goat. What is causing this change?
Serous atrophy of fat
Can be caused by starvation, severe cachexia
In addition to radiation, chemicals, and drugs, viruses can also interfere with hematopoiesis. What are some viruses responsible?
Feline parvovirus (panleukopenia)
Canine parvovirus
Equine Infectious Anemia
What pathology in this bone marrow can lead to pancytopenia?
Necrosis
What is the pathology in this bone marrow? What is probably causing it?
Supperative osteomyelitis (septic osteomyelitis)
Usually the result of bacterial infections.
What type of osteomyelitis would be diagnosed in this patient?
Granulomatous osteomyelitis.
*This patient has histoplasmosis. Granulomatous osteomyelitis is usually the result of fungal infections (histoplasma, coccidioides), and sometimes TB.
What is a potential complication of osteomyelitis?
Pancytopenia
Necropsy on a cat from the Ohio River Valley shows granulomatous uveitis, hepatitis, and splenitis. What is the likely causative agent?
Histoplasma capsulatum
Tissue aspirates from a necropsy of a cat in Missouri show large macrophages filled with schizonts. What was the likely cause of death?
Occlusion of the vessels of the lungs, brain, liver, LN, and spleen.
*The protozoal parasite is Cytauxzoon felis. In the schizogenous phase, marcophages become very large after phagocytosing schizonts and will occlude vessels. In the erythrocytic phase, anemia results.
Bone marrow hypoplasia or atrophy, or decreased proliferative activity, is associated with an increase in what type of marrow?
Yellow
Bone marrow aspirate from a Guinea Pig showing replacement of marrow with collagen-rich fibrous connective tissue. What is this called and what was the cause?
Myelofibrosis cused by Vitamin C deficiency (scurvy)
*Replacement of marrow is called myelophthisis. It can be replaced with CT, or by malignant neoplasias.
What are the 2 mechanisms of pancytopenia?
Myelophthisis
Abnormality/Destruction of hematopoietic cells
Replacement of yellow marrow by red marrow at the metaphysis and endosteal surface of the diaphysis indicates what process?
Marrow hyperplasia
What mechanisms will cause increased cell production (hyperplasia) in the bone marrow?
Decreased cells in the blood due to increased peripheral demand
Adequate numbers of hypofunctional cells in the blood.
Hyperplastic bone marrow is found in a 4 month old calf with leukocytosis and a history of recurrent bacterial infections. What disease does this cow likely have?
Bovine Leukocyte Adhesion Deficiency (BLAD)
Bone marrow of a horse. What is the process?
Bone marrow (erythroid) hyperplasia
A horse dies after recurrent episodes of fever and severe thrombocytopenia. PM exam of the bone marrow shows very red, active marrow. What is the pathogenesis?
Bone marrow hyperplasia secondary to EIA
What class of lymphoid/myeloid neoplasias are more aggressive, with poorly differentiated cells, making them harder to diagnose?
Acute leukemias
Acute Lymphoid Leukemia in cattle is assocated with infection by what virus?
Bovine Leukemia Virus (BLV)
*BLV can cause lymphoma
Myeloproliferative diseases are less common than lymphoproliferative, and are mainly diseases of what species?
Dogs and cats
Diagnosis of a myeloproliferative disorder can be supported if there is expression of:
CD34
A dog presents to your clinic for weakness and lethargy. The dog is pale, and on abdominal palpation you think you can feel the spleen. Radiology confirms that the spleen and liver are enlarged. You preform a blood smear and find lymphoblasts in circulation. What is the tenative diagnosis?
Lymphoproliferative disease
(lymphoblastic leukemia)
PM exam of bone marrow from a cow shows soft, white nodules that bulge on cut surface, and a bone marrow cavity that is filled with yellow/white tissue. What is the diagnosis?
Lymphoma
(Lymphoid leukemia or Leukemic lymphoma?)
Necropsy on a dog shows hepatosplenomegaly. What neoplasia of the hematopoietic system can cause these features?
Lymphosarcoma (LSA) -lymphoproliferative disease
A 9 year old dog presents to your clinic for sudden lameness, and the xrays are as pictured. What diagnostic lab values will confirm your diagnosis?
Hypercalcemia
Monoclonal gammopathy (paraprotein/M protein)
Markedly increased plasma cells in marrow
*The disease is multiple myeloma (neoplasia of plasma cells). Osteolysis is present in 25-66% of cases and starts in the vertebrl bodies, and flat bones of the skull and pelvis.
Cutaneous plasmacytomas of the skin or mucous membranes are usually (benign/malignant).
Benign
Extramedullary plasmacytomas, featuring amyloidosis in dogs, horses, and cats, are (benign/malignant).
Malignant
A client brings in her Rottweiler to have a lump examined. You aspirate the lump and see many abnormal histiocytes. Aspirate of a lymph node nearby shows multinucleated cells, anisokaryosis, anisocytosis, and abnormal mitotic figures. What is the diagnosis?
Histiocytic sarcoma (malignant)
Cutaneous and systemic histiocytosis are ______ canine immunoregulatory disorders.
Non-neoplastic
Benign tumors of young dogs, of Langerhans cell origin.
Canine cutaneous histiocytoma
Cutaneous neoplasm of cats, which is initially indolent, and is derived from dendritic cells.
Feline progressive histiocytosis
A FeLV positive cat has cytopenia of multiple cell lines and non regenerative anemia. A bone marrow aspirate shows hypercellularity of the cytopenic cell lines with less than 30% blasts. What is the diagnosis?
Myelodysplastic Syndrome (MDS)
*maturation abnormality of marrow cells, but not clearly neoplastic. About half of these cases in humans will progress to leukemia. This can be hereditary in Polled Herefords.
What system is responsible for eliminating waste products from the CNS while we sleep, and becomes less effective as we age?
Glymphatic system
Hemal lymph nodes, which are small and dark red, are common in what animals?
Ruminants
Biposy of a lymph node, showing proliferation of abnormal cells in the subcapsular sinus. This is likely metastasis from what neoplasia in felines?
Mammary carcinoma
*Tend to metastsize to lymph nodes. Mammary carcinomas are usually malignant in cats and benign in dogs.
Lymph node of a dog from a polluted urban area. What is the MDx and etiology?
MDx: anthracosis
Et: Carbon particles retained in macrophages
Histo of a swollen lymph node from a cow. Why is the LN enlarged?
The LN is draining. The cortex appears normal, and there are many cells in the subcapsular sinus.
Young horse with abscessation of the mandibular, pharyngeal, and parotid lymph nodes. What is the causative agent?
Streptococcus equi subsp equi
*Strangles
Mesenteric LN from a horse confirmed to be infected with Streptococcus equi subsp equi. What is the disease name?
Bastard Strangles
*Infection with Strep equi subsp equi that causes abscesses anywhere other than in the pharyngeal area.
You arrive on a farm to examine a horse that recently recovered from Strangles. You find the horse to have edema of the head and limbs, and the mm of the eye are as pictured. What is the disease and pathogenesis?
Purpura Hemorrhagica
Complication of infection with S. equi. Type III immune-mediated vasculitis caused by IgA and AgM complexes.
You arrive at a farm to examine a sheep with a large swelling in the mandibular area. What is the likely cause?
Infection with Corynebacterium pseudotuberculosis
*Caseous lymphadenitis
LN from a sheep infected with C. pseudotuberculosis. Which of the following is the chronically infected lymph node?
Bottom (onion)
Lymph node from a cow infected with Mycobacterium bovis (tuberculosis). What is the MDx?
Granulomatous lymphadenitis
What is causing granulomatous lymphadenitis in this patient?
Infection with Histoplasma capsulatum
Enlarged and bulging LN from a pig.
MDx: Diffuse granulomatous lymphadenitis
What disease causes this condition in pigs?
Postweaning Multisystemic Wasting Disease (PMWS)
*Porcine circovirus 2
(causes B and T cell depletion)
Botryoid inclusions in macrophages are indicative of what disease?
PMWS in pigs
*porcine circovirus 2
What are the white areas in this reactive LN from a canine?
Lymphocyte proliferation
A bovine lymph node that is bulging on cut surface. What is the pathology?
Lymphosarcoma
Necropsy on a 3 month old chicken shows the following lesions. What is causing the pathogenesis?
T cell lymphoma.
*Marek’s Disease: Gallid Herpesvirus 2. The only herpesvirus capable of causing cancer. T cells proliforate and infiltrate tissues. Sciatic nerves will also be affected and will look enlarged (peripheral neuritis).
On PM exam of the abdomen of a recently euthanized dog, you find the spleen as pictured. Is this a normal finding?
Yes, barbiturates will produce an enlarged, congested (bloody) spleen.
Other causes of bloody spleen include:
Congestion (volvulus and sedation)
Acute hyperemia (inflammation and anthrax)
Acute hemolytic anemia (autoimmne, parasites)
While performing a necropsy of a dog with a history of storage disease, you find the spleen uniformly enlarged and firm. What are the causes of “meaty” spleens?
Proliferation of cells (inflammation, lymphoma, mast cell tumor)
Storage material and amyloid (plasma cells)
Phagocytosis
What is the cause of the splenic degeneration in this old canine patient?
Siderofibrosis of the capsule
*Gamma-Gandy bodies. Not usually significant but can be a sequel of hemorrhage.
What is the cause of splenic nodules in this patient?
Incomplete contraction
Necropsy on a 4 year old hamster shows splenomegaly. What likely caused this abnormality?
Amyloidosis
(extracellular)
This bloody spleen of a recently euthanized horse represents what type of circulatory disturbance?
Acute passive congestion
*Barbiturate-induced
This spleen, taken from a dog with gastrosplenic torsion, represents what type of circulatory disturbance?
Acute passive congestion
Necropsy of a pig who died from Hog Cholera (Classical Swine Fever) with spleen as pictured. What is the circulatory disturbance?
Infarct
Seeding of the omentum in this patient was caused by:
Splenic rupture (splenosis) and formation of numerous accessory spleens
The splenic hematoma seen in this canine patient presents what risk to the live animal?
Risk of rupture and internal hemorrhage
You find a cow dead in pasture, bloated and with blood coming out of its nose, mouth, and anus. You carefully collect the ear to send to a reference lab, and state veterinarians perform a necropsy. The spleen is acutely enlarged and oozes blood when cut. Cytology results are as pictured. What is causing acute splenic hyperemia in this patient?
Anthrax
Lymphoid hyperplasia in this horse is causing _______ splenitis.
Chronic (granulomatous)
PM exam on a Beaver shows white-grey milliary foci throughout the splenic parenchyma. What is the etiology for the necrosupperative splenitis in this animal?
Francisella tularensis
Necropsy on a Great Horned Owl shows acute, miliary necrotizing hepatitis and splenitis. You suspect Herpes Inclusion Body Disease. How did the owl contract this?
Consuming pigeons that are subclinically infected with Columbid Herpesvirus 1 (CoHV-1)
Spleen of a turkey infected with Mycobacterium avium. What is the MDx?
Multifocal granulomatous splenitis
Necropsy on a dog that had a history of trauma 2 years ago shows multiple splenic fragments in the abdomen, with the rupture sites having been healed by fibrosis. Which of these fragments would have still been functional?
The one attached to the hilus (blood supply)
What complication of nodular hyperplasia was possible in this patient?
Splenic rupture.
(The capsule is tense and stretched over the nodule)
A 9 year old dog is brought in to the clinic after being HBC. The dog is tachycardic with thready pulses. You perform a FAST scan and find that there is fluid in the abdominal cavity. Exploratory surgery reveals splenic abnormalities as pictured. What likely caused the hemoabdomen in this patient?
Splenic rupture.
*Spleens with nodular hyperplasia are prone to rupture with trauma, resulting in hemoabdomen and exsanguination. Nodules in this patient could be an age related change.
Xrays on a dog show a possible mass in the cranial abdomen. Exploratory surgery reveals a very large mass associated with the spleen. How likely is it that this mass is malignant?
Unlikely. Since the mass is so large, it is likely a splenic hemangioma.
A dog presents to the clinic anemic and lethargic. ALT and AST are increased, and platelet counts are low. Abdominal xrays indicate that there may be a mass on the spleen. Considering the most likely diagnosis, do you expect the splenic mass/messes to be large or small?
Small.
*Hemangiosarcoma. More common than hemangioma and masses will be smaller.
Spleen of a dog, with multifocal nodules. What is the diagnosis?
Lymphosarcoma
During surgery, you find the spleen of a cat to be diffusely covered in multiple white nodules. FNA shows macrophages with vacuolation, and a couple that are multinucleated. What is the most likely diagnosis?
Histiocytic sarcoma
A herd of cattle was exposed to Bovine Leukemia Virus, and necropsy on one of them shows a large mass in the cranial mediastinum. What age is this particular animal likely to be?
Young. Calves will get thymic lymphomas when exposed to virus, whereas adults will develop more systemic lymphomas.
Necropsy on a cat reveals a large mass in the cranial mediastinum. What is the most likely diagnosis?
Thymic lymphosarcoma
You find a large mass in the cranial mediastinum of a goat. Considering the species, what is the most likely diagnosis?
Thymoma
*Goats have the highest incidence of thymomas
Multiple 4 week old chicks die on a farm, and illness seems to be spreading to the others. Necropsy on the chicks shows varying degrees of bursal abnormality, as pictured. Some are enlarged and edematous, some normal size and hemorrhagic, and some are severely atrophied. What is the likely cause of death in these chicks?
Immunodeficiency caused by lymphoid depletion
*Infectious Bursal Disease (the most important disease of broilers in the US) targets pre-B lymphocytes in the Bursa of Fabricius. (Gumboro Disease, Avian Infectious Bursitis)
