Macroscopic Veterinary Pathology There is no one correct way to describe a slide. Bruce Williams, DVM, DACVP Senior Pathologist, JPC Email: williams@cldavis.org Tissue from a sheep Tissue from a foal Be concise. Look at the center of the slide. Gotcha! 1
Assume the color balance is correct. Handwriting is important. Your answers must be legible. (Reports, too!) 2
Know which lesions are important. Tissue from a pig Pay attention to the question. This image cannot currently be displayed. Never change your answer. Get your eyes checked 30 days before the exam. This image cannot currently be displayed. Leave no answers. 3
Practice, practice, practice Tissue from a rat Noah s Archive C. L. Davis Foundation Gross Course every March in Washington John King s Show and Tell Every department has diamonds in the rough! Tissue from a foal Tissue from a turkey New for 2008! Morphologics and causes are not enough anymore Pathogenesis Other lesions or affected organs Likely sequela Associated clinical signs 4
Tissue from a guinea pig. Pathogenesis? Name another organ where you may find a lesion.. Tissue from a cat. Name an associated clinical sign. Name a pre-existent lesion. Have some canned morphologics ready in advance. Tissue from a rat 5
Tissue from a frog Conventional Wisdom If you can t recognize it, it s got to be... Reproductive tract (especially female) Mammary gland Lymph node Tissue from a llama 6
Tissue from a llama Tissue from a rabbit Tissue from a horse Tissue from a rat 7
How low can you go? Tissue from a frog Tissue from a calf Tissue from a puppy Tissue from a rat 8
Beware of: Tissue from a cat. Common lesions in uncommon species Unique views of common lesions Tissue from a black rat snake Tissue from a leopard Tissue from a squirrel 9
Tissue from a guinea pig Beware of: Something missing or reduced in size Aplasia Hypoplasia Atrophy Necrosis Tissue from a calf 10
Tissue from a horse Tissue from a horse Examine the whole slide before jumping to an answer. 11
Tissue from a cat Tissue from a horse. Tissue from a cat 12
COLOR Red Hyperemia Congestion Hemorrhage Remember, it s usually masking NECROSIS!!! Tissue from a pig Tissue from a pig White Inflammation Mineral Bone Keratin Fibrous connective tissue Urates Lipid Necrosis (it s not white, it just has no color) 13
Tissue from a monkey Tissue from a hawk Tissue from a horse Tissue from a rabbit Tissue from a sheep 14
Tissue from a pig Tissue from a chicken Tissue from a king snake Tissue from a duck 15
Tissue from a piglet Yellow Bilirubin Fat Myelin breakdown (it s mostly fat) Meconium Inflammation, fibrin Tissue from a foal. Tissue from a foal. 16
Tissue from a deer Orange Sterols Fat is a major component Green Tissue from a foal Bile pigments Eosinophilic inflammation Necrosis Algal or fungal organisms Hemosiderin 17
Tissue from a rat Tissue from a chicken Black Melanin Blood pigments (especially oxidized) Fluke pigment Exogenous carbon Hydrogen sulfide Tissue from a piglet Tissue from a sheep 18
Tissue from a sheep Tissue from a sheep Tissue from a cat 19
Tissue from a cat Clear Yes, it s not really a color Fluid filled cysts Transudates Mucin Tissue from a cat Tissue from a rabbit Contour Something has been added. Fluid - edema or hemorrhage Cells - inflammation, neoplasia, or normal elements Gas - usually bacterial 20
Tissue from a rabbit Tissue from a chicken Tissue from a goat Tissue from a rat 21
Tissue from a ferret Tissue from a rat Tissue from a cat Tissue from a calf Tissue from a pig 22
Tissue from a fish Contour Something has been added. Fluid - edema or hemorrhage Cells - inflammation, neoplasia, or normal elements Gas - usually bacterial Tissue from a pig Tissue from a rabbit Tissue from a sheep Shape Triangular Usually vascular in origin Point of triangle often is at a thrombosed vessel. 23
Shape Rhomboid Also vascular in origin Tissue from a pig Shape Round Vascular Cysts Tissue from a rat 24
Tissue from a deer Shape Amorphous Vascular This image cannot currently be displayed. Tissue from a horse Shape Tissue from a monkey Cavitated Schirrous neoplasm Pox lesion (central necrosis and peripheral hyperplasia) 25
Tissue from a turkey This image cannot currently be displayed. Shape This image cannot currently be displayed. Straight lines Think distention of pre-existent anatomical structure. This image cannot currently be displayed. Tissue from a rabbit This image cannot currently be displayed. Tissue from a rabbit 26
This image cannot currently be displayed. Formulating a Morphologic Diagnosis Required Organ Distribution Process Optional Modifiers Severity Duration Formulating a Morphologic Diagnosis Organ Formulating a Morphologic Diagnosis Distribution Distribution Modifiers Tissue from a ferret Focal - a single discrete site Focally extensive - a large discrete site 27
Distribution Modifiers Multifocal - multiple discrete sites separated by normal tissue Distribution Modifiers Multifocal to coalescing - Multiple lesions which come together to form a larger lesion Tissue from a nude mouse Tissue from a pig Distribution Modifiers Diffuse - total involvement of a tissue 28
Tissue from a donkey Distribution Modifiers Unilateral Distribution Modifiers Bilateral Tissue from a chicken Distribution Modifiers Bilaterally symmetrical 29
Tissue from a horse Distribution Modifiers Miliary Disseminated Embolic Tissue from a calf Distribution Modifiers Transmural - throughout all layers of the wall of a hollow organ Tissue from a piglet 30
Inflammatory Modifiers Suppurative Tissue from a foal Tissue from a rat Inflammatory Modifiers Tissue from a pig Fibrinous 31
Tissue from a guinea pig Inflammatory Modifiers Yes, you can combine them! (You re welcome.) Inflammatory Modifiers Granulomatous 32
Inflammatory Modifiers Necrotizing Tissue from a rhesus monkey Tissue from a turkey Inflammatory Modifiers Hemorrhagic NO!!! It s NECROSIS!! Tissue from a pig 33
Inflammatory Modifiers Ulcerative Inflammatory Modifiers Proliferative Tissue from a ferret Tissue from a snake 34
Tissue from a horse Inflammatory Modifiers Lymphocytic-plasmacytic Tissue from a cat Tissue from a bison Inflammatory Modifiers Catarrhal Tissue from a pig 35
Tissue from a cow Tissue from a seal pup Temporal Modifiers Acute Subacute Chronic Chronic-active Types of Gross Diagnosis Types of Gross Diagnosis Morphologic Diagnosis - summarizes the lesion, but does not identify the cause Diffuse severe granulomatous enteritis Etiologic Diagnosis - Composed of the site and the causative agent Mycobacterial enteritis or Intestinal mycobacteriosis 36
Types of Gross Diagnosis Etiology or Cause - be as specific as you can. Mycobacterium avium, var. paratuberculosis Types of Gross Diagnosis Name the Disease - the commonly acknowledged name of the condition or disease. Johne s disease Formulating a Morphologic Diagnosis Tissue from a cat Name the Disease - the commonly acknowledged name of the condition or disease. Johne s disease The Withs Two or more related lesions which combine to result in a single morphologic diagnosis. Proliferative and eosinophilic mesenteric arteritis with aneurysm formation Necrotizing vasculitis with dermal infarcts 37
Tissue from a rat Tissue from a rat Neoplasms The morphologic diagnosis for a neoplasm is simply a combination of the site and type of neoplasm. Iridal melanoma Cutaneous hemangiosarcoma Thyroid adenocarcinoma Tissue from a horse 38
Exceptions One-word morphologics abound (the word contains both the organ and process. Tissue from a cat Tissue from a pig Tissue from a turkey Exceptions Tissue from a horse When in doubt, use both a morphologic description and the name of a disease entity....focally extensive epithelial agenesis (epitheliogenesis imperfecta)... 39
Tissue from a horse Avoid: Use of vague morphologic diagnoses which may represent different lesions to different pathologists. Cirrhosis - Macronodular hepatic regeneration Nephrosis - Acute renal tubular necrosis 40