2014 Descriptive Vet Path Course. Histo Exam #1 Key

Transcription

1 2014 Descriptive Vet Path Course Histo Exam #1 Key

2 Test 1, Slide 1. Tissue from a dog. MICROSCOPIC DESCRIPTION: Prostate gland: Multifocally and extensively infiltrating the prostate gland (1 pt.), and lining or filling and effacing the urethra, prostatic glands and ducts (1 pt.) or forming islands and trabeculae and short interwoven papillary fronds (1 pt.) is an unencapsulated (1 pt.), moderately cellular, poorly circumscribed (1 pt.) neoplasm composed of polygonal epithelial cells (1 pt.) on a dense fibrovascular stroma (1 pt.). Neoplastic cells have indistinct cell borders, a moderate amount of eosinophilic cytoplasm (1 pt.) which often contain a large clear vacuole which peripheralizes the nucleus (signet ring) (1 pt.), an irregularly round vesiculate nucleus (1 pt.) with finely stippled chromatin and variably distinct nucleoli. Anisocytosis and anisokaryosis is moderate to marked, and the mitotic rate averages 2 per 400X HPF (1 pt.). There are scattered individually necrotic neoplastic cells or islands of neoplastic cells have central areas of comedo lytic necrosis admixed with mineral (1 pt.). Islands of neoplastic cells are often surrounded by desmoplasia (1 pt.), and the intervening stroma is infiltrated by moderate numbers of lymphocytes, plasma cells, macrophages, and fewer neutrophils (1 pt.). The remainder of the gland exhibits diffuse papillary and cystic hyperplasia (1 pt.), and there are multifocal dilated ducts lined by attenuated epithelial cells and are either empty or filled with eosinophilic homogenous secretory product (1 pt.). MORPHOLOGIC DIAGNOSIS: 1. Prostate gland: Transitional cell carcinoma (2 pt) 2. Prostate gland: Hyperplasia, papillary and cystic, diffuse, marked (1 pt.). O/C: (1pt.)

3 Test 1, Slide 2: Tissue from a horse MICROSCOPIC DESCRIPTION: Spinal cord: Multifocally and most notably in the ventral (1 pt.) half of the spinal cord are extensive coalescing areas of infarction (1 pt.) In these areas, there is loss of normal neurofibrillary architecture (1 pt.) and replacement by numerous foamy macrophages (Gitter cells) (1 pt.), fewer astrocytes and oligodendroglia. The larger infarcts have areas of cavitation (1 pt.) with drop-out and loss of all neural tissue. Vessels in the affected areas are lined by plump, reactive endothelial cells.(1 pt.) Multiple vessels, particularly in the meninges are occluded by variably eosinophilic to gray (1 pt.), vaguely laminated (1 pt.) material (fibrocartilagenous emboli) (1 pt.). In the less affected areas of spinal cord, neurons are markedly swollen, have lost their pyramidal shape (1 pt) and have displacement of Nissl substance (1 pt.) to the periphery (central chromatolysis) (1 pt.). White matter tracts, including spinal nerve rootlets have marked myelin sheath swelling (1 pt.); swollen, deeply eosinophilic degenerate axons (1pt.); or loss of axons with replacement by Gitter cells (Wallerian degeneration) (1pt.) MORPHOLOGIC DIAGNOSIS: Spinal cord: Necrosis, bilateral, severe, with spheroids, neuronal central chromatolysis, Wallerian degeneration, and multiple fibrocartilaginous emboli. (3 pt.) NAME THE CONDITION: Fibrocartilaginous embolus (fibrocartilaginous infarcts OK) (2 pt.)

4 Test 1, Slide 3: Tissue from a dog. MICROSCOPIC DESCRIPTION: Liver: There is diffuse hepatocellular degeneration and loss (1pt.). Diffusely, centrilobular and midzonal hepatocytes are markedly swollen (1pt.) due to an accumulation of numerous variably-sized discrete cytoplasmic lipid droplets (2pt.); the marked swelling effaces plate architecture and obstructs sinusoids. There is less prominent microvesicular lipidosis of portal hepatocytes. Multifocally, centrilobular hepatocytes are shrunken, hypereosinophilic, rounded up and individualized, and have pyknosis or karyorrhexis (necrosis) (1pt.). Hepatocytes contain small amounts of a brown granular pigment (1pt.), which is also present in Kupffer cells (1pt.) as well. In subcapsular areas, hepatocytes occasionally contain moderate amounts of an amphophilic material which has a fan-shaped, crystalline appearance (1pt.). There is marked biliary reduplication (1pt.) extending from portal areas and dissecting between periportal hepatocytes. Rarely, the lumens of hyperplastic biliary ducts contains rare sloughed epithelial cells, neutrophils, or macrophages. Biliary epithelial cells are often enlarged, crowded, and have vesicular nuclei. (1pt.) Bile casts are common (cholestasis) (1pt.).Portal lymphatics are dilated and contain numerous lipophages and fewer sloughed hepatocytes (1pt.)., often with brown granular pigment, and there are moderate numbers of histiocytes as well as low numbers of lymphocytes and plasma cells within portal triads (1pt.) There is mild fibrosis of portal triads. MORPHOLOGIC DIAGNOSIS: Liver: Hepatocellular degeneration, necrosis, and loss, diffuse, moderate, with marked hepatocellular lipidosis and biliary hyperplasia. (4pt.) CAUSE: Aflatoxin (2pt.) O/C: (1pt.)

5 Test 1, Slide 4. Tissue from a rat. MICROSCOPIC DESCRIPTION: Small intestine and mesentery: Diffusely, the walls of mesenteric arteries are markedly thickened (1pt.) and the vessels themselves are tortuous (1pt.). Centrally, lumina are often narrowed (1pt.) and occluded by organizing fibrin thrombi (1pt.), which occasionally contain lines of Zahn, entrapped hemorrhage, and numerous elongate rhomboid hemoglobin crystals (1pt.), as well as degenerate neutrophils and cell debris. The endothelium is multifocally eroded. Multifocally, the subendothelial tunica intima is markedly expanded by thick bands of deeply eosinophilic hyaline protein (1pt.) which is occasionally lamellated and fibrillar (fibrinoid material) (1pt.). The tunica media is markedly expanded by hyperplastic and disorganized smooth muscle (1pt.) which is often separated by mild edema, and more centrifugally reactive fibroblasts (1pt.), collagen, numerous small caliber blood vessels (1pt.), aggregates of hemosiderin and hematoidin-laden macrophages (1pt.) and infiltrated by numerous viable and degenerate neutrophils (1pt.), fewer macrophages, lymphocytes, plasma cells, rare multinucleated giant cells macrophages, eosinophils and necrotic debris (1pt.). Similar inflammatory cells extend into the tunic adventitia, and the adjacent, mildly edematous mesentery (1pt.). Multifocally, there is mild atrophy of mesenteric fat. MORPHOLOGIC DIAGNOSIS: Mesenteric arteries: Arteritis, proliferative and necrotizing, chronic-active, diffuse, severe, with fibrinoid necrosis and thrombosis. (3pt.) NAME THE CONDITION: Polyarteritis (periarteritis) nodosa (2pt.) O/C: (1pt.)

6 Test 1, Slide 5. Tissue from a mouse MICROSCOPIC DESCRIPTION: Lung: Effacing 90% (1 pt.) of the lung are multifocal to coalescing pyogranulomas (1 pt.) centered on up to 300 um diameter (1 pt.) large colonies (1 pt.) of basophilic 1um cocci bacteria (1 pt.), which are surrounded by abundant central lytic necrosis (1 pt.) and degenerate neutrophils (1 pt.) admixed with mineral surrounded by numerous large foamy epithelioid macrophages (1 pt.) and fewer Langhans and foreign body multinucleated giant cell macrophages.(1 pt.), Surrounding these are numerous lymphocytes and plasma cells (1 pt.), which are rimmed by dense fibrosis (1 pt.). Bacterial colonies are rarely encased by hypereosinophilic, hyaline clubbed Splendore-Hoeppli material. Adjacent bronchioles are filled with an exudate (1 pt.) composed of numerous degenerate neutrophils, lytic necrotic debris, and sloughed respiratory epithelial cells. Adjacent less affected alveoli are filled with numerous large foamy alveolar macrophages (1 pt.) and multinucleated giant cells which often contain clear acicular cholesterol clefts (1 pt.) and numerous 2-7 um long hyaline, refractile, acicular eosinophilic crystals (1 pt.) admixed with eosinophilic edema fluid (1 pt.) and fewer lymphocytes and plasma cells. MORPHOLOGIC DIAGNOSIS: 1. Lung: Pneumonia, pyogranulomatous, multifocal to coalescing, severe, with numerous large colonies of cocci. (3 pt.) 2. Lung: Pneumonia, histiocytic, multifocal, marked with intrahistiocytic eosinophilic crystals. (1 pt.)

7 Test 1, Slide 6. Tissue from a ringneck pheasant chick. ULTRASTRUCTURAL DESCRIPTION: This electron micrograph contains cross sections of up to four epithelial cells (1 pt.) with a low, even microvillar border (1 pt.), apical tight junctions, rare desmosomes, variably dense cytoplasm, endoplasmic reticulum, numerous mitochondria, and lysosomes containing dark black material (likely lipid) (1 pt.) (intestinal or colonic epithelium) (1 pt.). There is a single erythrocyte within the lumen, and cross sections of several macrophages (1 pt.) subjacent to the epithelial cells (1 pt.). There are no cross sections of nuclei visible within the epithelial cells.. All of the epithelial cells show evidence of cellular degeneration (1 pt.), to include loss of surface substructure (microvilli) (1 pt.), cellular swelling (1 pt.), cytosolic lucency (1 pt.), numerous dilated profiles of endoplasmic reticulum (1 pt.), and large lysosomes with dense lipid containing material (likely an autophagosome). The two more degenerate epithelial cells contain a single round moderately electron-dense cytoplasmic viroplasmic inclusion (1 pt.). One cell contains numerous large irregularly shaped vacuoles (1 pt.) (presumably either dilated endoplasmic reticulum or lysosomes) which contain numerous mature membrane-bound viral particles (2 pt.) which are randomly arrayed. ULTRASTRUCTURAL DIAGNOSIS: Small intestine (colon OK): Enterocyte degeneration, diffuse, moderate to severe, with cytoplasmic viral particles and viral inclusion. (2 pt.) CAUSE: Avian rotavirus (avian coronavirus OK) (2 pt.) O/C: (1 pt.)