Vet Clin Path 2013 Flashcards
Histologic section of the inguinal lymph node. Dx? Describe.
Dx: B-cell lymphoma with plasmacytoid differentiation
(A) Note the effacement of normal architecture.
(B) The lymphocyte population has a bimorphic appearance and contains a high number of mitotic figures (arrows). The inclusions seen in the cytologic specimen are poorly visible.
B-cell lymphoma with plasmacytoid differentiation, atypical cytoplasmic inclusions, and secondary leukemia in a dog. Vet Clin Pathol 42/1 (2013) 40–46.
Cytochemical and immunochemical staining of histologic (A, B) and cytologic (C) specimens of inguinal lymph node of a dog with B-cell lymphoma with plasmacytoid differentiation. What is the staining characteristics?
(A) The inclusions are distinctly positive (bright pink) with periodic acid-Schiff, indicating carbohydrate content.
(B) Positive nuclear staining for MUM-1 is seen in both large and small lymphocytes. MUM-1 immunostain with 3-amino-9-ethylcarbazole (AEC) chromogen.
(C) Intense diffuse cytoplasmic IgM staining is observed within both large and small lymphocytes. Abundant background staining indicates large amounts of extracellular IgM. IgM immunostain
B-cell lymphoma with plasmacytoid differentiation, atypical cytoplasmic inclusions, and secondary leukemia in a dog. Vet Clin Pathol 42/1 (2013) 40–46.
Fine-needle aspirate of a mesenteric lymph node from a dog. Dx? Describe.
Dx: Mesocestoides tetrathyridium infection
Hundreds of clear, refractile, calcareous corpuscles (arrows) from a ruptured cestode larva.
Cestode infection in 2 dogs: cytologic findings in liver and a mesenteric lymph node. Vet Clin Pathol 42/1 (2013) 103–108.
Fine-needle aspirate of liver from a dog. Dx? Describe.
A Mesocestoides tetrathyridium with 4 visible round suckers (arrows).
Cestode infection in 2 dogs: cytologic findings in liver and a mesenteric lymph node. Vet Clin Pathol 42/1 (2013) 103–108.
Direct smear from tracheal wash in a dog. What are the structures?
diatoms
The presence of diatom algae in a tracheal wash from a German Wirehaired Pointer with aspiration pneumonia. Vet Clin Pathol 42/2 (2013) 221–226.
Endotracheal wash from a dog. Dx? What stain is this?
Dx: Mixed inflammation with intra- and extracellular lipid accumulation, compatible with lipid pneumonia.
Oil Red O stain reveals accumulation of lipid, both free within the background, and within the cytoplasm of a macrophage.
What is your diagnosis? An endotracheal wash from a dyspneic 3-month-old female Labrador Retriever. Vet Clin Pathol 42/4 (2013) 527–528.
Histo from an abdominal mass arising from a kidney of a dog. Dx? Describe. What is the stain in B? What are the important structures in D?
Renal carcinoma in a dog.
(A) Neoplastic renal tubules are surrounded by a thick, eosinophilic basement membrane and contain eosinophilic material within their lumina. H&E.
(B) Laminin immunostain. Light brown staining of the globules indi- cates positive immunoreactivity. 3,3′-diaminobenzidine tetrahydrochlo- ride chromogen. (C) and
(D) Transmission electron microscopy images of hyaline globules in renal carcinoma in a dog. Laminated accumulations of basement membrane are seen surrounding neoplastic renal tubules (asterisk) and within tubular lumens (boxed).
What is your diagnosis? Intracranial mass in a dog. Vet Clin Pathol 42/3 (2013) 389–390.
Peripheral blood smears made one day (Dog 1, A, B, and Dog 2, C, D), 4 days (Dog 3, E, F), 3 days (Dog 4, G, H), and 5 days (Dog 5, I, J) after vincristine administration. Describe the changes.
(A) Two polychromatophils contain several atypical nuclear remnants (Howell-Jolly bodies).
(B) A polychromatophilic RBC contains 2 nuclear bodies of unequal sizes and with undulated margins.
(C) Asynchronous maturation of the nucleus and cytoplasm in a nucleated RBC.
(D) A polychromatophilic RBC with 4 variably sized Howell-Jolly bodies.
(E) A rubricyte either with 2 nuclei of unequal sizes, or one nucleus with an abnormal nuclear bleb.
(F) An RBC with an abnormally large nuclear remnant adjacent to a smaller nuclear remnant (Howell-Jolly body) or an abnormal bleb.
(G) A metarubricyte has extruded its nucleus (on the left) and another one is in the process of extruding its nucleus (on the right).
(H) A polychromatophilic RBC has a diameter smaller than the mature RBC adjacent to it.
(I) A metarubricyte has a cerebriform nucleus. (J) An atypical erythroid mitotic figure with lagging chromosomes is present.
Erythrocyte dysplasia in peripheral blood smears from 5 thrombocytopenic dogs treated with vincristine sulfate. Vet Clin Pathol 42/4 (2013) 458–464
Histologic appearance of scapular mass in a hamster. Dx? Describe.
Dx: extraskeletal OSA
(A) Malignant mesenchymal neoplasm with both myxoid and compact areas, comprised of spindloid, hyperchromatic cells
(B) Presence of small amounts of extracellular material admixed within the compact areas
What is your diagnosis? Scapular mass in a Chinese hamster. Vet Clin Pathol 42/4 (2013) 533–534.
Histologic section from a submandibular fluid-filled mass in a horse. Dx? What are the cells + for? Describe.
Dx: Reactive lymphoid cell population, consistent with lymph fluid from an obstructed duct.
PROX-1 staining of the nuclei of lymphatic endothelium lining the channels of the mass (arrow), while normal vascular endothelium fails to stain.
What is your diagnosis? Fluid surrounding a submandibular mass from a horse. Vet Clin Pathol 42/4 (2013) 531–532.
Histologic sections of affected intestinal epithelium from a dog with peritonitis after enterotomy for foreign body removal. Dx? Describe.
Candida peritonitis
Serosa (*) is markedly thickened by infiltration of a mixed population of inflammatory cells, including neutrophils, macrophages, lymphocytes, and plasma cells. H&E, bar = 1 mm. Insets: The left inset is a magnified area of inflammation taken from the box in the serosa. H&E. The right inset highlights numerous Candida yeast and pseudohyphae from the box in the serosa. Gomori’s Methamine Silver stain.
Candida peritonitis in dogs: Report of 5 cases. Vet Clin Pathol 42/2 (2013) 227–233.
Imprints of a cystic lesion closely associated with the choroid plexus within the fourth ventricle of a dog. Dx?
Dx: Epidermoid cyst
What is your diagnosis? Cystic mass in the fourth ventricle of the brain of a dog. Vet Clin Pathol 42/3 (2013) 387–388.
Histologic section of a mammary mass of a dog. Dx? Describe. What is the arrow pointing to?
Pyogranulomatous mastitis characterized by an infiltration of mammary gland tissue by numerous macrophages, leaving few remnants of normal glandular tissue (arrowhead). Dx: Mycobacterium kansasii
Mastitis caused by Mycobacterium kansasii infection in a dog. Vet Clin Pathol 42/3 (2013) 377–381.
Serum protein electrophoresis in a cat. Describe. Dx?
Dx: multiple myeloma
monoclonal gammopathy
Left to right, fractions are albumin (29.68%, 3.44 g/dL; reference interval [RI] 2.1–3.3 g/dL), alpha 1 globulins (3.88%, 0.45 g/dL; RI 0.2–1.1 g/dL), alpha 2 globulins (13.11%, 1.52 g/dL; RI 0.4–0.9 g/dL), beta globulins (9.92%, 1.15 g/dL; RI 0.9–1.9 g/dL), and gamma globulins (43.40%, 5.03 g/dL; RI 1.7–4.4 g/dL).
Total protein was 11.59 g/dL (RI 5.4–7.8 g/dL), and A/G ratio was 0.42 (RI 0.45–1.19).
Hemophagocytic syndrome in a cat with multiple myeloma. Vet Clin Pathol 42/1 (2013) 55–60.
Cytocentrifuged preparation of BAL (upper) and CSF (lower) in a dog. Dx? Describe.
Dx: Disseminated angiostrongylosis
Angiostrongylus vasorum LI larvae have a characteristic cephalic button (short arrow) and a sinuous and sharp tail with an indented subterminal dorsal spine (long thin arrow). (Lower) Cerebrospinal fluid in a Nageotte counting chamber. Turk’s solution
What is your diagnosis? Bronchoalveolar lavage and cerebrospinal fluid from a dog in Italy. Vet Clin Pathol 42/1 (2013) 109–110.
FNA of a mammary mass in a dog. Dx? Describe the arrangements.
Dx: canine mammary micropapillary carcinoma revealing different architectural patterns.
(A) and (B)- Small papillary arrangements without fibrovascular cores.
(C) A morula-like cluster of epithelial cells.
Clinical, cytologic, and histologic features of a mammary micropapillary carcinoma in a dog. Vet Clin Pathol 42/3 (2013) 382–385.
Fecal smear from a Mallard duckling. Dx?
Dx: Coccidiosis
What is your diagnosis? Fecal smear from a Mallard duck (Anas platyrhynchos). Vet Clin Pathol 42/1 (2013) 111–112.
Cytochemistry on blood smears from a turtle with lymphoid leukemia. Which stains was this tumor + for?
Cytochemistry on blood smears, 9100 objective (A–D); and immunohistochemistry on kidney sections, 910 objective (E–F), from a turtle with lymphoid leukemia.
The neoplastic cells were positive for CD3 and some were positive for ANBE.
Heterophils positive for SBB and ALP.
Erythrocytes often have a single focal area of positive staining with ANBE and SBB.
(A) Alpha naphthyl butyrate esterase (ANBE); (B) Sudan black B (SBB); (C) Chloroacetate esterase (CAE); (D) Alkaline phospha- tase (ALP); (E) CD-3; (F) Pax-5.
Chinese Box turtle (Cuora flavomarginata) with lymphoid leukemia characterized by immunohistochemical and cytochemical phenotyping. Vet Clin Pathol 42/3 (2013) 368–376.
Neutrophil with cytoplasmic inclusions in a blood smear from a cat. Dx?
Phagocytized mast cell granules
What is your diagnosis? Blood smear from a cat. Vet Clin Pathol 42/3 (2013) 393–394.
Histologic section of an intraoperative cerebral mass biopsy from a dog. Dx? Describe. What is the stain in the second picture?
Dx: Granular cell tumor, PAS
What is your diagnosis? Impression smears of a cerebral mass from a dog. Vet Clin Pathol 42/2 (2013) 240–241.
Histologic sections of small intestine from a Mallard duckling. Dx? Describe the structures in each pic.
Dx: coccidiosis.
(A) Multiple enterocytes contain a single schizont with multiple merozoites
(B) Sloughed epithelial cells within the intestinal lumen contain unsporulated oocysts
What is your diagnosis? Fecal smear from a Mallard duck (Anas platyrhynchos). Vet Clin Pathol 42/1 (2013) 111–112.
Mass around optic nerve of a dog. Dx? Describe. What are the cell types in each picture?
Dx: Meningioma
(A) The long, rod-shaped, gray structures on the left and upper center are outer segments of photoreceptor rod cells. A few wider, perhaps cone- shaped, cytoplasmic fragments may be present, but outer segments of cone cells were not confidently identified. Nuclei of these photoreceptor cells are bi-lobed with a linear white cleavage between dense chromatin on 2 sides. These small, round nuclei are on the right and bottom and are slightly larger in diameter than an erythrocyte.
(B) Two small clusters of bi-lobed nuclei from the photoreceptor cells are at the upper center and toward the lower right. Several nuclei on the right are damaged, swollen and lack this bi-lobed pattern. The nerve fibers on the lower left were likely from the outer plexi- form layer of the retina.
(C) Nuclei of the outer nuclear layer are in the upper right. Flat, wide polygonal cells from the pigmented epithelial layer are in the left center.
(D) Cells of the pigmented epithelial layer have characteristic pointed oval-shaped melanin granules.
Cytologic appearance of retinal cells included in a fine-needle aspirate of a meningioma around the optic nerve of a dog. Vet Clin Pathol 42/2 (2013) 234–237.
Fine-needle aspirates from cervical lymph node (top) and spleen (bottom) from a dog that whelped stillborn puppies. Dx?
Dx: Disseminated Mycobacterium avium complex infection
What is your diagnosis? Lymph node aspirates from a dog with stillbirth. Vet Clin Pathol 42/3 (2013) 391–392.
Mass around optic nerve of a dog. Dx? Describe.
Dx: Meningioma (The cytologic diagnosis was mesenchymal neoplasia without prominent signs of malignancy)
Meningioma cells had moderate to large amounts of cytoplasm. Variable cell shapes and indistinct “fuzzy” cell borders suggested a mesenchymal cell type. Nuclei displayed mild anisokaryosis, a uniform chromatin pattern and small nucleoli, suggesting a benign tumor. Nuclei were about 1.5–2.5 times an erythrocyte in diameter.
Cytologic appearance of retinal cells included in a fine-needle aspirate of a meningioma around the optic nerve of a dog. Vet Clin Pathol 42/2 (2013) 234–237.
Blood smear from a Common Buzzard. Dx? Describe.
Dx: avian malaria
Note the long cylindrical organism with brown to black refractile granules in an RBC.
What is your diagnosis? Blood smear from a Common Buzzard (Buteo buteo)
Photomicrograph of a histologic section of a lung mass in a rabbit. Dx? Describe. What are the cells positive for in the bottom picture?
Dx: histiocytic sarcoma
(A) Sheets of round-to-polygonal neoplastic histiocytic cells expand alveolar septa (double-head arrow). Alveolar spaces lined by cuboidal epithelial cells (type II pneumocytes, arrowheads) are filled with large atypical neoplastic histiocytic cells with mitotic figures (arrows). H&E stain.
(B) The cytoplasm of neoplastic cells shows strong diffuse immunoreactivity for vimentin, while bronchiolar epithelial cells lining a bronchiolus (*) are negative.
Pulmonary histiocytic sarcoma in a rabbit. Vet Clin Pathol 42/3 (2013) 364–367.
Direct smears of abdominal fluid from a dog with bile peritonitis due to a gall bladder rupture and a dog with peritonitis after enterotomy for foreign body removal. Dx? Describe.
Candida peritonitis
(A) Numerous budding yeast within a degenerative neutro- phil. (B) Yeast elongation with germ tube formation within a macrophage (arrows). (C) Elongated pseudohyphae noted as a series of conjoined yeast with obvious constrictions at septal sites. (D) True hyphae with no constrictions at septal sites.
Candida peritonitis in dogs: Report of 5 cases. Vet Clin Pathol 42/2 (2013) 227–233.
(A) Blood smear from a horse, (B) lymph node aspirate. Dx?
Dx: leukemic small cell leukemia or chronic lymphocytic leukemia.
Small lymphocytes with small rim of basophilic cytoplasm and occasional cytoplasmic pseudopodia, and round nuclei, with a dense chromatin pattern and rare incospicuos small nucleoli. (B) Note also occasional cytoplasmic pseudopodia and frequent cytoplasmic fragments in the background.
Leukemic small cell lymphoma or chronic lymphocytic leukemia in a horse. Vet Clin Pathol 42/3 (2013) 301–306.
Cystic mass in the fourth ventricle of the brain of a dog. Dx? Describe.
Histologic section of an epidermoid cyst closely associated with the choroid plexus within the fourth ventricle of a dog. Note the lining with stratified squamous epithelium on the right side, the desquamated epithelial cells and keratin debris in the cystic center, and the hemorrhagic areas on the far right side.
What is your diagnosis? Cystic mass in the fourth ventricle of the brain of a dog. Vet Clin Pathol 42/3 (2013) 387–388
Blood smear from a turtle. Dx? Describe.
Dx: lymphoid leukemia.
There are numerous atypical neoplastic cells, including some with cytoplasmic granulation (A) and some karyorrhectic cells (B).
Macrophage with nonspecific cell debris and yellow-brown cytoplasmic pigment (melanomacrophage) (C). A
small phagocytic cell and 3 heterophils (H) (D).
Chinese Box turtle (Cuora flavomarginata) with lymphoid leukemia characterized by immunohistochemical and cytochemical phenotyping. Vet Clin Pathol 42/3 (2013) 368–376.
Splenic aspirate from a cat. Dx? Describe. What are the arrows pointing at?
Dx: multiple myeloma and hemophagocytic syndrome
There are numerous plasma cells (short arrow) and moderate numbers of macrophages with phagocytized mature erythrocytes, platelets (long arrow), and rarely plasma cells (arrowhead). Inset: Macrophage containing mature erythrocytes and platelets.
Hemophagocytic syndrome in a cat with multiple myeloma. Vet Clin Pathol 42/1 (2013) 55–60.
Histopathologic appearance of the right prescapular lymph node of a dog. Dx? Describe. What is the stain in the lower picture?
Dx: mycobacterial granulomatous lymphadenitis
(A) The lymph node topography is disrupted by typical confluent epithelioid granulomas characterized by central necrosis (a) surrounded by epithelioid macrophages (b) with a peripheral rim of lymphocytes (c) H&E, 10 objective.
(B) Numerous acid-fast positive bacilli (red-stained rods), consistent with mycobacteria within the cytoplasm of epithelioid macro- phages and outside of cells in the central necrotic material. Ziehl– Neelsen
A mycobacterial coinfection in a dog suspected on blood smear. Vet Clin Pathol 42/4 (2013) 516–521.
Impression smears of an intraoperative cerebral mass biopsy from a dog. Dx? What is the stain in the second picture?
Dx: Granular cell tumor, PAS
What is your diagnosis? Impression smears of a cerebral mass from a dog. Vet Clin Pathol 42/2 (2013) 240–241.
Concentrated abdominal fluid from a dog. Dx?
Dx: T-cell lymphoma with eosinophilic infiltrates
(cyto interp was highly suspicious for neoplastic effusion, most likely lymphoma, with marked eosinophilic inflammation; other differential diagnoses included parasitic infection, hypereosinophilic syndrome, and mast cell neoplasia with secondary eosinophilic peritonitis)
What is your diagnosis? Abdominal fluid from a dog. Vet Clin Pathol 42/1 (2013) 113–114.
Fine-needle aspirate of liver from a dog. Dx? Describe.
A tadpole-like Mesocestoides tetrathyridium with 2 round suckers (arrows) adjacent to a larger acephalic metacestode. Inset. A Mesocestoides tetrathyridium with 2 visible, round suckers (arrows).
Cestode infection in 2 dogs: cytologic findings in liver and a mesenteric lymph node. Vet Clin Pathol 42/1 (2013) 103–108.
FNA from a lung mass in a rabbit. Dx? Describe.
Dx: histiocytic sarcoma (cytologic interpretation was malignant neoplasm with histiocytic sarcoma considered most likely)
(A) Note many individualized and loosely adherent sheets of pleomorphic round cells.
(B) Atypical cells demonstrate marked anisokaryosis, binucleation, and occasional mitotic figures.
Pulmonary histiocytic sarcoma in a rabbit. Vet Clin Pathol 42/3 (2013) 364–367.
Cytocentrifuged preparation of transtracheal wash fluid from a horse. Dx?
Marked neutrophilic inflammation, septic; given morphology of bacteria and association with cilia, Bordetella spp. most likely
What is your diagnosis? Equine transtracheal wash fluid. Vet Clin Pathol 42/4 (2013) 529–530
What is important about this cell and in what condition can it be found?
Botryoid nuclei characterized by increased numbers of nuclear segments radially arranged with spoke-like, deli- cate chromatin filaments that connect them to the center of the cell. Chromatin condensation is lacking. Heatstroke.
Botryoid nuclei in the peripheral blood of a dog with heatstroke. Vet Clin Pathol 42/2 (2013) 145–149.
Bone marrow aspirate from a cat. Dx? Describe.
Dx: multiple myeloma and hemophagocytic syndrome
There are many plasma cells (short arrow) and moderate numbers of macrophages with phagocytized mature ery- throcytes, metarubricytes, and neutrophils (long arrow).
Hemophagocytic syndrome in a cat with multiple myeloma. Vet Clin Pathol 42/1 (2013) 55–60.
Endotracheal wash from a dog. (A) direct smear, (B) cytocentrifuge preparation. Dx?
Mixed inflammation with intra- and extracellular lipid accumulation, compatible with lipid pneumonia.
What is your diagnosis? An endotracheal wash from a dyspneic 3-month-old female Labrador Retriever. Vet Clin Pathol 42/4 (2013) 527–528.
Mass around optic nerve of a dog. Dx? Describe.
Dx: Meningioma
The cells are often arranged in swirling concentric circles and whorls. No psammoma bodies are seen. The cell shapes varied from elongated, thin cells to more plump rounded cells with more abundant cytoplasm. Nuclei often had 1–2 small to medium sized nucleoli and displayed mild to moderate anisokaryosis.
Cytologic appearance of retinal cells included in a fine-needle aspirate of a meningioma around the optic nerve of a dog. Vet Clin Pathol 42/2 (2013) 234–237.
Blood smear from a Common Buzzard. Dx? Describe the structures.
Dx: Avian malaria
2 types of intracellular organisms. The smaller one, ranging in diameter from 2 to 3 lm, was frequently observed (4–5 parasites/100 RBCs) and had a ring-shaped body with a single circular nucleus.
What is your diagnosis? Blood smear from a Common Buzzard (Buteo buteo)
Histologic sections of a gingival oral malignant melanoma with cartilaginous differentiation in a dog. What is the tumor positive for?
(A) S100 (B,C) Melan-A
What is your diagnosis? Gingival mass in a dog. Vet Clin Pathol 42/1 (2013) 115–116.
Fine-needle aspirate of a mesenteric lymph node from a dog. Dx? Describe.
Dx: Mesocestoides tetrathyridium infection
Clear refractile calcareous corpuscles (arrows) within a segment of a cestode larva.
Cestode infection in 2 dogs: cytologic findings in liver and a mesenteric lymph node. Vet Clin Pathol 42/1 (2013) 103–108.
Histologic section of duodenum in a dog. Dx? Describe. What are the cells + for in the inset?
Dx: T-cell lymphoma with eosinophilic infiltrates
Note the focal aggregate of discrete large lymphocytes with small amounts of amphophilic cytoplasm and large round-to-oval nuclei with finely stippled chromatin and multiple prominent nucleoli. Mitotic figures (long arrow) and few eosinophils (arrowheads) also are present.
Inset: Immuno- histochemical staining of duodenum. The aggregate of large round cells are immunoreactive for CD3.
What is your diagnosis? Abdominal fluid from a dog. Vet Clin Pathol 42/1 (2013) 113–114.
Cytocentrifuged preparations of bronchoalveolar lavage fluid and CSF from a dog. Dx?
Disseminated angiostrongylosis
What is your diagnosis? Bronchoalveolar lavage and cerebrospinal fluid from a dog in Italy. Vet Clin Pathol 42/1 (2013) 109–110.
Histologic sections of lung from a dog. Describe the findings and what the arrows are pointing to. What stain is C & D?
(A) Bronchial and bronchiolar lumina and adjacent alveolar spaces contain numerous large macrophages (long thin arrow) admixed with moderate numbers of foreign body type multinucleated giant cells (short wide arrow), fi- broblasts, neutrophils (long wide arrow), fibrin, moderate numbers of lymphocytes (short thin arrow), and plasma cells. H&E.
(B) Low numbers of extra- cellular fungal hyphae (short arrow) are present; they are tan, up to 5 lm wide, septate, and have thin parallel walls. Numerous macrophages (long arrow) are also seen.
(C) Extracellular plant material and mixed inflammatory cells are present. Periodic-acid Schiff stain.
(D) Low numbers of extracellular fungal hyphae are observed. Periodic-acid Schiff stain
The presence of diatom algae in a tracheal wash from a German Wirehaired Pointer with aspiration pneumonia. Vet Clin Pathol 42/2 (2013) 221–226.
Cytocentrifuged preparation of transtracheal wash fluid from a horse. Dx? Describe.
Dx: Marked neutrophilic inflammation, septic; given morphology of bacteria and association with cilia, Bordetella spp. most likely
A cluster of ciliated respiratory epithelial cells are present with cilia-associated rod-shaped bacteria (long arrow). Rod-shaped bacteria are also found free in the background (short arrow).
What is your diagnosis? Equine transtracheal wash fluid. Vet Clin Pathol 42/4 (2013) 529–530
Fine-needle aspirate of a gingival mass in a dog. Dx?
Dx: Oral malignant melanoma with cartilaginous differentiation (diagnosis was oral malignant melanoma, and the eosinophilic granules and extracellular matrix were noted as unusual for this tumor)
What is your diagnosis? Gingival mass in a dog. Vet Clin Pathol 42/1 (2013) 115–116.
Histologic section of a mammary mass in a dog. Dx? Describe the arrangements.
Dx: canine mammary micropapillary carcinoma.
(A) Neoplastic cells arranged in morula-like micropapillae without fibrovascular cores inside mammary lumina.
(B) Morula-like clusters of malignant epithelial cells surrounded by clear spaces, probably representing lymphatic invasion.
Clinical, cytologic, and histologic features of a mammary micropapillary carcinoma in a dog. Vet Clin Pathol 42/3 (2013) 382–385.
Histologic section of submandibular lymph node froma horse. What are the cells + for?
Dx: leukemic small cell lymphoma or chronic lymphocytic leukemia.
(A) The cortex is distended by a monomorphic population of small lymphocytes with very little cytoplasm and a round hyperchromatic nucleus.
(B) Small lymphocytes are immunoreactive for CD3.
Leukemic small cell lymphoma or chronic lymphocytic leukemia in a horse. Vet Clin Pathol 42/3 (2013) 301–306.
Bone marrow aspirates made 3 days (Dog 1, A) and 5 days (Dog 5, B) after vincristine administration. Describe the changes.
(A) An internuclear string between 2 erythroid precursors that have nuclei with bizarre, indented or blebbed nuclear margins, suggestive of incomplete segregation of the chromosomes during mitosis.
(B) An erythroid precursor is undergoing mitosis and has lagging chromosomes (right) and a polychromatophil has an abnormally large nuclear remnant (left).
Erythrocyte dysplasia in peripheral blood smears from 5 thrombocytopenic dogs treated with vincristine sulfate. Vet Clin Pathol 42/4 (2013) 458–464
Histologic section of a bone marrow core from a horse. Dx? What are the cells + for?
Dx: leukemic small cell lymphoma or chronic lymphocytic leukemia.
(A) Lym- phocytes are increased in number and account for 30% of all nucleated cells.
(B) Small lymphocytes are immunoreactive for CD3.
Leukemic small cell lymphoma or chronic lymphocytic leukemia in a horse. Vet Clin Pathol 42/3 (2013) 301–306.
Histologic section of a gingival mass in a dog. Dx? Describe.
Dx: Oral malignant melanoma with cartilaginous differentiation
cartilaginous foci (stars) and nests of pleomorphic neoplastic cells (arrows).
What is your diagnosis? Gingival mass in a dog. Vet Clin Pathol 42/1 (2013) 115–116.
Fine-needle aspirate of liver from a dog. Dx? Describe.
A Mesocestoides tetrathyridium containing one round sucker (thick arrow) and many clear, small, refractile, calcareous corpuscles (thin arrows).
Cestode infection in 2 dogs: cytologic findings in liver and a mesenteric lymph node. Vet Clin Pathol 42/1 (2013) 103–108.
Top- Blood smear, bottom- inguinal lymph node from a dog. Dx? Describe.
Dx: B-cell lymphoma with plasmacytoid differentiation with leukemia
Dx: B-cell lymphoma with plasmacytoid differentiation
(A) There is a markedly expanded population of intermediate-sized lymphocytes with clumped chromatin, inapparent or small nucleoli, and a moderate amount of pale blue cytoplasm. The lymphocytes lack the morphologic features of the lymphocytes in the inguinal lymph node.
(B) Note the bimorphic population of lymphocytes (large immature cells mixed with smaller plasmacytoid cells with small dark nuclei) and the variable appearance of the cytoplasmic inclusions.
B-cell lymphoma with plasmacytoid differentiation, atypical cytoplasmic inclusions, and secondary leukemia in a dog. Vet Clin Pathol 42/1 (2013) 40–46.
Histologic sections from a turtle (A) Kidney. (B) Liver. (C) Testis. Dx?
Dx: lymphoid leukemia. There is diffuse neoplastic lymphocyte infiltration.
Chinese Box turtle (Cuora flavomarginata) with lymphoid leukemia characterized by immunohistochemical and cytochemical phenotyping. Vet Clin Pathol 42/3 (2013) 368–376.
Fine-needle aspirate from a peripheral lymph node of a dog. Dx? What is the stain in the lower picture?
Dx: mycobacterial lymphadenitis.
(A) Few intact neutrophils and macrophages in a proteinaceous background with necrotic and calcified debris, lipid droplets, and numerous free long negatively stained rods suggestive of mycobacteria. Modified MGG,
(B) Numerous acid- fast positive rods (red-stained rods) consistent with mycobacteria, within the cytoplasm of neutrophils and macrophages, and free in the back- ground. Ziehl–Neelsen
A mycobacterial coinfection in a dog suspected on blood smear. Vet Clin Pathol 42/4 (2013) 516–521.
Peripheral blood smear (A-E) and bone marrow (F) from a dog. Dx? Describe.
Dx: Rangelia vitalii.
Note parasites in RBCs (A) and neutrophils (B), morphologic changes such as agglutination of RBCs (C) and spherocytes (D), increased numbers of reticulocytes (E), and nucleated erythroid precursors in bone marrow (F).
Hematologic and bone marrow changes in dogs experimentally infected with Rangelia vitalii.
Peripheral blood smear of a dog. Dx?
Dx: mycobacteriosis
A neutrophilic leukocytosis with a left shift was observed, accompanied by negatively stained rods suggestive of mycobacteria in the cytoplasm of monocytes (in the center of the picture), but also in some neutrophils (not shown).
A mycobacterial coinfection in a dog suspected on blood smear. Vet Clin Pathol 42/4 (2013) 516–521.
Cytocentrifuged preparation of fluid from a fluctuant submandibular mass in a horse. Dx?
Dx: Reactive lymphoid cell population, consistent with lymph fluid from an obstructed duct.
What is your diagnosis? Fluid surrounding a submandibular mass from a horse. Vet Clin Pathol 42/4 (2013) 531–532.
Peripheral blood film of a dog. Dx? What are the structures?
Trophozoites of Babesia canis vogeli.
(A) 1, 2, or 4 intraerythrocytic trophozoites.
(B) Four intracellular trophozoites (arrow).
(C) Four extracellular trophozoites (arrow)
Babesia canis vogeli, Ehrlichia canis, and Anaplasma platys infection in a dog. Vet Clin Pathol 42/4 (2013) 471–475.
Fine-needle aspirate from scapular mass in a hamster. Dx?
Dx: Extraskeletal osteosarcoma.
What is your diagnosis? Scapular mass in a Chinese hamster. Vet Clin Pathol 42/4 (2013) 533–534.
Peripheral blood smears from a dog. Dx?
Dx: chronic myelomonocytic leukemia.
(A) Blood sampled prior to treatment. Note the increased numbers of atypical monocytoid cells (arrow heads), the nuclei of which have atypical nuclear contour and chromatin patterns, and prominent nucleoli. Note immature cells in the neutrophil series (large metamyelocyte and band neutrophil, arrows). (B) Blood sampled one week after chemotherapy. Note the presence of large atypical monocytoid cells as well as smaller mature monocytes. (C) Faint magenta granules can be observed in the cytoplasm of the central large atypical monocytoid cell.
Molecular characterization of canine BCR-ABL-positive chronic myelomonocytic leukemia before and after chemotherapy. Vet Clin Pathol 42/3 (2013) 314–322.
Immunocytochemistry of small lymphocytes in a peripheral blood smear from a horse with leukemic small cell lymphoma or chronic lymphocytic leukemia. What were the cells positive/negative for?
(A) Positive immunoreactivity for CD3 (B) nega- tive immunoreactivity for CD79a
Leukemic small cell lymphoma or chronic lymphocytic leukemia in a horse. Vet Clin Pathol 42/3 (2013) 301–306.
Smears of fine-needle aspirates of an abdominal mass arising from a kidney of a dog. Dx?
Renal carcinoma with accumulation of basement membrane (BM, hyaline globules).
What is your diagnosis? Intracranial mass in a dog. Vet Clin Pathol 42/3 (2013) 389–390.
