Cool Cases (Gross and Histo)
Case 8. Molluscum Contagiosum, Equine.
Case 7. afip-07-08-conference-14-slide-3
Case 6. afip-07-08-conference-15-slide-3
Case 5. Dr. Craig’s Mystery Case (4-08)
Case 4.
This macaque was innoculated with SIV as part of a research study. The animal presented with diarrhea and was euthanized due to poor response to treatment and poor prognosis.
This macaque became immunosuppressed following SIV inoculation, permitting secondary infections to occur. This image shows the classic colonic suppurative inflammation associated with Cytomegalovirus infection. CMV is an unusual virus because it induces host cells to produce inflammatory proteins that draw a neutrophilic immune response. Neutrophils are seen expanding the interstitial spaces between the colonic epithelium. The colon is abnormally proliferative — how many mitotic figures can you see?
The same macaque (with SIV and CMV) acquired another secondary infection — with Balantidium coli. The B. coli organisms are visible amongst the colonic glands. The suppurative inflammation from the CMV infection is still visible in the interstitium.
Case 3.
A 9 yo MBD presented for weakness, ataxia, and syncopal/seizure episodes. The dog was hypoglycemic and was euthanized due to poor prognosis. This image is from a section of the dog’s pancreas. Recall that the pancreas has both exocrine and endocrine functions performed by cells that have distinct histological appearances. In the bottom right corner of the image are normal acini of exocrine pancreas. These pancreatic cells are large with “bi-colored” cytoplasm (pink and purple) and these cells are responsible for secreting enzymes like lipase and enzyme precursors such as trypsinogen. Separated from the normal exocrine tissue by a thin fibrous band is a large population of smaller cells with pale cytoplasm. These cells are beta cells — the cells that make and secrete insulin. Normal beta cells are usually located in small islands of endocrine pancreas, and respond to normal feedback mechanisms. When beta cells become neoplastic, they may secrete insulin constitutively. Since insulin promotes cellular uptake of glucose, the result is hypoglycemia. Insulinomas are “benign” tumors — notice the encapsulation and the regular, homogenous appearance of the beta cells. Despite their benign classification however, insulinomas can cause severe clinical signs and even death due to hypoglycemia.
Case 2.
This image shows a section of liver from a mouse. In the center of the image is a small blood vessel that is surrounded by an abnormal granulomatous (macrophage) infiltrate. Granulomatous inflammation can be associated with many etiologies, such as fungal infections or mycobacterial infections. By applying an acid fast stain, we see that the perivascular macrophages are filled with pink rods — a positive result for Mycobacterium! Enlarge the image to see the rods more closely.
Case 1.
This is liver from a mouse — but what is different about it compared to case 2? Most of the field is composed of large, polygonal hepatocytes. In the center of the field is a collection of neutrophils — but watch out! This is not suppurative inflammation! Notice how small and “neat” the neutrophils are. When neutrophils are part of an inflammatory response they are reactive and much larger. This case is an example of extramedullary hematopoeisis — in other words, these are baby neutophils being born in the liver!
