General Pathology

VPM 152

Disorders of Cell Growth

& Neoplasia

Lab/tutorial 1

Enrique Aburto Winter 2015

MOCK LABORATORY EXAM GENERAL PATHOLOGY - VPM 152

Friday April 4, 2014 YOU NEED TO BRING: CLIP BOARD (TO WRITE ON) & PEN / PENCIL YOU NEED TO WEAR: LAB COAT + Gloves (optional, don’t “pick at” specimens) Schedule: Group A (Breau to Emmons) 10:30 to 10:50 Group B (Forcier to Korechy) 10:55 to 11:15 Group C (Lebang to Profit) 11:20 to 11:40 Group D (Quinlan to Wilson) 11:45 to 12:05 Exam in PM Demo room -- PLEASE BE ON TIME! REMINDERS: This is a MOCK EXAM - you will gain more information from this experience if you conduct the examination as if it was REAL! (note, an answer key will be provided to check your answers) There will be 6 stations with 18 minutes to complete the mock exam - so organize your time accordingly. Read the history carefully and answer the questions that are asked. [An answer key will be provided to check your answers] Do not panic! This is only a practice. This is a good time for you to evaluate yourself as to

what you do know and what you might need to learn or review for the final laboratory examination.

LABORATORY PRACTICAL EXAM

GENERAL PATHOLOGY - VPM 152

Thursday April 17, 2014

YOU NEED TO BRING: Clip Board (To Write On), Pen / Pencil

WHAT TO WEAR: Lab Coat

Gloves (optional - since specimens can only be touched under supervision)

REMINDERS: Read the history carefully and answer the questions that are asked!

There will be 25 stations with 80 minutes to complete the exam - so organize your time accordingly (~ 3

minutes per station)

With 30 students and 25 stations there will be times when there are 2 people at one station

(but no more than 2 people at any one station at a time)

Do not touch the specimens without supervision - if you need to manipulate a

specimen to see a different angle or determine texture, please put your hand up so an instructor can assist

you.

Be warned that any observation of cheating will result in a grade of zero for this exam - -- - do not let your

eyes wander

SCHEDULE: Group A 9:30 to 10:50 Breau to Korecky

Group B 11:00 to 12:20 Labang to Wilson

Gross Description:

A proper description must include:

•Distribution - spatial arrangement of the lesions (random, focal,

multifocal, coalescing, segmental, diffuse, symmetrical etc.)

•Contour/Shape (raised, depressed, round, square etc.)

•Colour

•Size (size of lesions, increases or decreases in organ size)

•Texture/consistency - what does the surface look like and how

does it feel (soft, firm, hard, friable, fluctuant, crepitus)

Morphologic diagnosis?

(includes the organ or tissue and the name of the main lesion)

What kind of growth does this lesion represent?

(anaplasia, hypoplasia, hyperplasia, dysplasia, neoplasia etc)

Normal calf

Brain from a 3 day old calf (right side)

Hypoplasia = failure of an organ / tissue to reach its normal size

• Breach calf, pulled by producer

• Unable to rise or stand

• Hyperextension of head and neck

Morphologic

Diagnosis::

Cerebellar

hypoplasia

Etiology?

In-utero infection

with BVD virus

Hip dysplasia, bilateral, dog.

Both femoral heads and

acetabula are flattened and

distorted by periosteal new bone

proliferation (arrows) .

Note - These changes are

secondary to the abnormal

organization/maturation

(dysplasia) of the tissues that

compose the coxofemoral joint.

Dysplasia of the hip causes

biomechanical abnormalities

and instability of the joint, which

predisposes it to repetitive

subluxation (loss of contact

between the joint surfaces)

Single pale raised nodular mass (top left). Histo (top right): The mass is well-

defined, non-encapsulated and composed of mature pale (vacuolated)

hepatocytes, pushing the adjacent normal parenchyma (arrows).

Pathologic Basis of Veterinary Disease (2006), 4th ed., Mosby-Elsevier

Liver from a dog. Describe the lesion.

Morphologic diagnosis? Hepatic nodular hyperplasia, focal

Clinical significance? Usually an incidental finding; needs to be

differentiated from hepatocellular tumors (adenoma /

well-differentiated carcinoma); preneoplastic change?

http://w3.vet.cornell.edu/nst/nst.asp

Hyerplastic nodules are white and

project above the surface (left , top).

Microscopically hyperplastic nodules

(N) are composed of numerous

small, well differentiated acini (a)

a a

Pathologic Basis of Veterinary Disease (2006), 4th ed., Mosby-Elsevier

Pancreas from an old dog.

Describe the lesion.

Morphologic diagnosis?

Pancreatic exocrine nodular

hyperplasia, multifocal

Other examples of

pancreatic nodular hyperplasia

Clinical significance?

Usually an incidental finding;

preneoplastic change in cats?

Nodular hyperplasia, spleen,

dogs. Multiple, red to pale, firm,

well-delineated and

nonencapsulated nodules are

present within the spleen. Nodules

are composed of mature

lymphocytes and hematopoietic

cells separated by congested red

pulp. These are a common age-

related change in dogs. Need to

differentiate these masses from

benign and malignant tumors.

Multiple nodules in the abomasal mucosa of a sheep (inset: higher magnification).

These represent areas of mucous metaplasia and hyperplasia, the sequelae of an

infection by the nematode (parasite) Ostertagia circumcincta.

Abomasum from a sheep

Section taken from an abomasal mucosal fold, at the level of a nodule of mucous metaplasia.

See the junction (curve line) between normal abomasal mucosal glands (N) and glands that have

undergone mucous metaplasia (M). A small number of lymphocytes are at the base of the

mucosa; likely remnants of the inflammation that was triggered by the parasitic infection.

N

M

Skin biopsy from an old dog (cut in half). Describe the lesion.

Morphologic diagnosis? Cutaneous polyp (fibroepithelial polyp, acrochordon)

An approximately 3 cm in largest dimension, firm to rubbery, pedunculated mass

protruding from the skin. The external surface is black (hyperpigmented and corrugated

(cawliflower-like). Cut surface is smooth and white.

Polyps may be hyperplastic /

inflammatory, hamartomatous or

neoplastic (benign). Intestinal

(colorectal) polyps (may lead to

carcinomas) Colonic adenomas. A, Pedunculated adenoma (endoscopic view). C, Pedunculated tubular adenoma supported by a stalk of fibrovascular connective tissue (s).

Schematic representation that shows the progression of intestinal adenomas (pedunculated and sessile polyps) into carcinomas

Robbins and Cotran Pathologic Basis of Disease (2010), 8th ed., Elsevier, Inc.

s

Clinical significance depends on

the nature or origin of the polyp

Polyps are any mucosal protrusion

usually supported by a stalk of

fibrovascular tissue (peduncle).

The normal liver architecture is replaced by numerous,

coalescing, pale yellow nodules, ranging in size from

~0.2 to 2 cm in diameter. The surrounding parenchyma

is retracted and rubbery.

Describe the changes:

Liver from an 8 year old Labrador Retriever

• The mass-like lesions are

nodules of hyperplastic tissue

(regenerative change)

• The surrounding (retracted)

parenchyma has been replaced

by fibrous tissue (fibrosis)

Morphologic Diagnosis:

Liver: Nodular hyperplasia,

multifocal, disseminated;

diffuse fibrosis (cirrhosis,

“end-stage liver”)

Compare cirrhosis with malignant hepatic neoplasia

Cirrhosis Malignant hepatic neoplasia

Pathologic Basis of Veterinary Disease (2006), 4th ed., Mosby-Elsevier

Abdominal cavity from a dog

Dx: Unilateral cryptorchidism and testicular hypoplasia (testicle in the right side)

Comment: Besides hypoplasia, retained testicles are predisposed to develop

Sertoli cell tumors.

Prostatic hyperplasia, dog, histo Prostate squamous metaplasia, dog

Prostate and urinary bladder

from a dog

There is marked symmetrical

enlargement of the prostate

Dx: Marked prostatic hyperplasia with multifocal squamous metaplasia

Comment: These changes are

commonly associated with estrogen-producing Sertoli cell tumors

Horse, normal bronchial

pseudostratified ciliated

columnar epithelium.

Horse, bronchial epithelium that

has undergone squamous

metaplasia in response to chronic

irritation / allergy.

Prostatic hyperplasia, dog

Prostate from a castrated dog

Morphologic diagnosis:

Prostatic atrophy, diffuse

Skin tumor in a 10-year-old Rottweiler.

Considering the external appearance and color,

what would be the most likely diagnosis?

Dx: Malignant melanoma

Post mortem examination revealed the presence of

multiple well-defined, dark-brown to black masses in

different areas of the brain. Assuming that these lesions

are metastases from the cutaneous mass, which would

be the most likely pathway of dissemination?

Answer: Hematogenous

Case #84

Clinical History:

• 5 yr-old, West Highland White terrier.

• skin mass from axillary region.

• has been present for the last 10 months with no apparent

change in size.

Skin biopsy, dog. Note well delineated, diffuse red mass in skin /

subcutis.

on low-power exam,

the mass is well

circumscribed and

extends from the

deep dermis of the

overlying skin into

the underlying

subcutis with at least

narrow zones of

normal tissue at the

peripheral margins.

the mass is well circumscribed but non-encapsulated.

at higher magnification, it consists of variable sized,

endothelial lined spaces / channels which are separated by

usually small amounts of fibrous stroma.

the nuclei of the lining endothelial cells are elongate with dense

chromatin, usually inapparent nucleoli, mild anisokaryosis and

no apparent mitotic figures.

Case #84

Description:

• on low-power exam, the mass is well circumscribed and extends from the deep

dermis of the overlying skin into the underlying subcutis with at least narrow zones of

normal tissue at the peripheral margins.

• at higher magnification, it consists of variable sized, endothelial lined spaces /

channels which are separated by usually small amounts of fibrous stroma.

• the nuclei of the lining endothelial cells are elongate with dense chromatin, usually

inapparent nucleoli, mild anisokaryosis and no apparent mitotic figures.

Morphologic diagnosis: Cutaneous hemangioma

Comment:

• a relatively common benign neoplasm of the dermis / subcutis of dogs

• usually solitary, but occasionally can occur at multiple sites.

• some cutaneous hemangiomas are associated with prolonged exposure to sunlight.