Case of the month is our diagnostic challenge. We present cases seen by Cornell University's Clinical Pathology Laboratory. These cover the gamut of venous blood smears, cytologic specimens and result (CBC, chemistry) interpretation, including those pesky erroneous results (usually due to preanalytical errors). A new case will be presented every month. Test yourself with the questions and photomicrographs and make your own diagnosis! The answer along with explanations and discussion is provided on the following page to see how close you came to the diagnosis. We also have an index of our previous cases (with answers) if you wish to see a list of all the cases. Please note, that the search tool does not search case of the month (yet!).
Kidney and third eyelid swelling in a dog
Case InformationA 12 year old male neutered mixed breed dog was brought to the Cornell University Veterinary Specialists (Cornell's satellite clinic in Connecticut) for evaluation of 3 abdominal masses involving the spleen, kidney and mesentery. The dog also had a prominent swelling of the third eyelid that was reported to have a mass-like effect. All four of the lesions were aspirated and submitted for cytological evaluation. The splenic aspirate contained components of red and white pulp, with no atypical cells or evidence of inflammation. The aspirate of the mesenteric mass contained free lipid admixed with blood. Photomicrographs of the kidney mass (Figure 1) and the swelling in the third eyelid (Figure 2) are shown below. Questions:
- Which lesion is likely the primary site?
- If the third eyelid mass was not present, how would this change the differential diagnosis list?
Peripheral blood from a cat
Case informationWhole blood from a 3 year old male neutered Himalayan cat was collected into an EDTA tube and submitted to the Animal Health Diagnostic Center at Cornell University for a complete blood count. The submitting hospital provided no clinical history. Review the pertinent data generated by the automated hematology analyzer (ADVIA 2120) and evaluate the photomicrographs below to answer the following questions: Complete Blood Count (CBC) – Truncated; Data from analyzer
- For which cell line is the analyzer clearly reporting spuriously decreased results?
- What is an artifact on a typical serum biochemistry panel that may be associated with this condition (in dogs), and what other type of specimen could you evaluate to confirm the artifact?
- How would you classify the large cells in Figures 2-3?
Laboratory data from a vomiting painful cat
Case InformationA 3 year old male neutered domestic short haired cat, presented to Cornell University Hospital for Animals Emergency Service with a 24 hour history of inappetence and acting painful when picked up. The cat had also vomited several times but was drinking water. On presentation, the cat was agitated, alert, responsive and vital parameters (temperature, pulse and respiration) were within normal limits. The cat was extremely painful on caudal abdominal palpation, but appeared to have a large bladder. A complete blood count (CBC) and serum chemistry was summited for analysis. A urinary catheter was passed with some difficulty but urine was obtained and submitted for urinalysis. Review the laboratory data provided and answer the following questions (only abnormal and pertinent laboratory data has been included).
|Complete Blood Count (CBC)|
|Serum Chemistry Panel|
- How would you interpret the leukogram?
- What type of acid-base disturbance(s) can you identify from the serum chemistry panel?
- What other diagnostic tests should be performed in this case?
Peritoneal fluid from an alpaca
Case informationA 6 year old female alpaca presented to the Cornell University Large Animal Hospital with a history of recumbency, anorexia, and dull mentation. Initial physical examination and diagnostic testing showed the animal was dehydrated and had clinical signs consistent with a proximal intestinal obstruction (decreased fecal output, significantly distended third gastric compartment, empty small intestine, and a shadowing object in the caudal aspect of the duodenal ampulla on abdominal ultrasonography). The hemogram showed a mild lymphopenia of 0.2 thousand/µL (reference interval, 1.1-5.5 thousand/µL), likely due to stress. Pertinent biochemical results are shown on the table below:
- What type of metabolic derangement is present?
- Identify and evaluate the cells labeled as "A" and "B" in Figure 2.
- What additional diagnostic tests would you do in this case?
Answers on next page
Tracheal wash from a horse
Case informationAn 8 year old Morgan gelding presented to the Cornell University Hospital for Animals with a 3 week history of serohemorrhagic skin lesions and a 1 week history of a progressively worsening cough. The horse had also recently lost 100 lb. On physical examination, multifocal oozing lesions were present on the left hip, lower aspects of three limbs and neck. No abnormal lung sounds were detected on auscultation with or without a rebreathing bag. Thoracic ultrasonographic and radiographic examination revealed diffuse lung consolidation and pleuritis, with a mixed pulmonary pattern and coalescing nodules, respectively. Blood samples were taken for a hemogram plus fibrinogen by heat precipitation and chemistry profile. Hemogram abnormalities included a mild neutrophilia of 7.3 thou/uL (reference interval: 2.7–6.6 thou/uL) and a mild hyperfibrinogenemia of 400 mg/dL (reference interval, 0-200 mg/dL). There was a mild hypoalbuminemia (2.5 g/dL, reference interval: 3.0–3.7 g/dL) and hyperglycemia (141 mg/dL, 71-113 mg/dL) on the biochemical panel. An endoscopic tracheal wash and blind bronchoalveolar lavage were performed and submitted for cytologic evaluation. Evaluate the representative photomicrographs of the direct smear of the tracheal wash and answer the questions posed below:
- What cell types are present in the smears (how would you characterize the results)?
- What are your differential diagnoses for the findings?
Joint aspirate from a tortoise
Case information:An approximately 18 month old, male Hermann’s tortoise presented for raspy breathing, exuberant, pink tissue over the eyes and being less active than normal. On physical examination the tortoise was small for his age, had increased respiratory rate and effort, was 5% dehydrated and would not open his eyes. While the tortoise was fully ambulatory, his left rear leg was swollen in the tarsal region. Whole body radiographs were taken to better assess the animal’s overall health. No abnormalities were seen in the lungs, but extensive bone loss and soft tissue swelling was noted in the region of the left tarsus. The left tarsal joint was aspirated and thick, gritty material was obtained. A portion of this sample was submitted for culture, while the remainder of the sample was assessed cytologically. Evaluate the photomicrographs of the submitted joint material and consider the following questions:
- What types of inflammatory cells are present?
- What are the structures indicated by the arrows in Figure 3 (also pictured in Figure 1A)?
- What is the final diagnosis based on the cytological findings?
Answers are on the next page
Biochemical results from a vomiting dog
Case information:A 2 year-old male castrated Cane Corso presented to the Cornell University Hospital for Animals for a two-day history of vomiting, hypoglycemia, and bradycardia. Blood-work performed at the referring veterinarian revealed a hyponatremia and hyperkalemia. No abnormalities were found on abdominal radiographs. Prior to referring the dog to the Cornell Emergency service, the rDVM began treatment with a bolus of 50% dextrose and 0.9% NaCl. The dog had a previous history of hospitalization for sepsis, vomiting, and diarrhea that had occurred one week after vaccination for rabies and distemper. Consequently, all vaccine protocols were discontinued and were therefore not up-to-date. On presentation, the dog was quiet but alert, and hypothermic at 97.3ºF. The remainder of the physical examination was within normal limits. The dog was started on intravenous fluids supplemented with glucose. Rapid in-house assessment tests, venous blood gas analysis, complete blood count, and a full serum chemistry panel were performed. Fluids, supplemented with dextrose, were continued overnight and a constant rate infusion of hydrocortisone was started. A free catch urine and stool sample were also submitted for evaluation. Review the laboratory data provided, and answer the following interpretive questions. (Abnormal and pertinent laboratory data have been included. Test results not included were within reference intervals.)
- Given the dog's clinical history and presentation, what is an unexpected finding in the hemogram results?
- What are the differential diagnoses for hypocholesterolemia and which is the most likely in this case?
- Presuming the dog's azotemia resolves with fluid therapy, how would you explain the reduced concentrating ability of the kidney?
Answers are on the next page
Conjunctival swab from a cat
Case informationA 6 year old male castrated domestic shorthair cat presented to the Cornell University Hospital for Animals (CUHA) emergency service for evaluation of worsening eye pain and inappetance. The cat was previously seen by the ophthalmology service at CUHA one week prior for evaluation of ocular discharge and conjunctival swelling of the left eye. In the latter examination, there was no evidence of penetrating trauma or foreign body. The cat was diagnosed with conjunctivitis and discharged with erythromycin ophthalmic ointment q 8 hours. Upon presentation to the emergency service, the cat demonstrated blepharospasm in both eyes. No other physical examination abnormalities were noted. A CBC and serum chemistry panel were performed and were largely unremarkable. A swab of the conjunctiva was performed and applied to a slide for cytologic evaluation. Representative images from the Wright’s stained smears are provided. Evaluate the provided images below and answer the following questions:
- What type of inflammation is present?
- Can you identify the cause of the inflammation?
- What additional diagnostic could be performed to confirm the cytologic diagnosis?
Synovial Fluid from a Foal
Case InformationA 3-week-old thoroughbred filly was presented to the Cornell University Hospital for Animals (CUHA) for acute left hind limb lameness and fever. Two days prior to presentation to CUHA, the filly was found acutely lame with a suspicion of trauma (stepped on by another horse). On presentation, the filly weighed 88 lb and had a temperature of 102.9ºF. The foal was quiet, alert and responsive, but was non-weight bearing on the left pelvic limb and had a moderately sized warm swelling over the left hip with no signs of external trauma. The rest of the physical examination was within normal limits. Blood was drawn for a complete blood count (CBC), equine IgG and serum amyloid A (SAA) testing. The CBC revealed a microcytic normochromic anemia (27% Hct, 34-46%) with a leukocytosis of 15.8 x 103/uL (reference interval, 5.2 - 10.1 x 103/uL) consisting of a mature neutrophilia of 13.1 x 103/uL (reference interval, 2.7 - 6.6 x 103/uL). The SAA concentration was higher than the upper detection limit of 2500 ug/mL and the fibrinogen concentration by heat precipitation was 700 mg/dL (reference interval, 100-200 mg/dL). The serum IgG was 671 mg/dL (reference interval in adults, 984 - 1685 mg/dL). Radiographic examination of the left pelvic limb and an abdominal ultrasonographic examination revealed no abnormalities. An ultrasound-guided fine needle aspirate was performed on the swelling and submitted to Clinical Pathology for a joint fluid analysis. The fluid was medium red, opaque and had decreased viscosity. The nucleated cell count was 51.5 x 103/uL, the RBC count was 441.2 x 103/uL, and the total protein (refractometer) was 5.7 g/dL. Examine the representative images of the joint fluid that are provided below and answer the following questions:
- How would you classify this joint fluid?
- Based on the cytological findings and the history of this foal, what are your differential diagnoses?
- What other diagnostic test should be performed?
Liver aspirate from a cat
Case informationAn 11-year-old male castrated domestic longhair cat presented to the Cornell University Hospital for Animals (CUHA) Emergency Service for a five day history of lethargy, anorexia, persistent hyperthermia, and increased liver enzymes. The cat was first brought to the primary care veterinarian for a two day history of lethargy and inappetance. At that time, bloodwork revealed hypoproteinemia, hypoalbuminemia, and hypocholesterolemia. Radiographs of the chest and abdomen showed mild hepatomegaly. The cat was treated with subcutaneous fluids, antibiotics, and prednisone. After one week of treatment, no improvement was noted and the cat was brought to CUHA for further evaluation. On presentation, the cat was bright, alert, and responsive, but was hyperthermic (104.8°F), tachycardic (210 bpm), and mildly dehydrated (5-7%). Physical examination also revealed mild icterus in both sclera and discomfort on cranial abdominal palpation. Blood was drawn for a CBC and chemistry panel. The CBC showed a mild normocytic normochromic nonregenerative anemia (hematocrit: 29%, reference interval [RI]: 31-48%). Results also showed a normal total leukocyte and neutrophil count with a mild left shift (0.2 thou/uL, RI: 0.0-0.1 thou/uL) and mild toxic change. Abnormal liver biochemical results are shown below:
- How would you interpret the biochemical results reported above?
- Based on the cytologic findings, what are your differential diagnoses for the underlying cause?
- What other diagnostic tests could be done in this case?