Ed Friedlander, M.D., Pathologist

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Welcome to Ed's Pathology Notes, placed here originally for the convenience of medical students at my school. You need to check the accuracy of any information, from any source, against other credible sources. I cannot diagnose or treat over the web, I cannot comment on the health care you have already received, and these notes cannot substitute for your own doctor's care. I am good at helping people find resources and answers. If you need me, send me an E-mail at Your confidentiality is completely respected. No texting or chat messages, please. Ordinary e-mails are welcome.

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Freely have you received, give freely With one of four large boxes of "Pathguy" replies.

I'm still doing my best to answer everybody. Sometimes I get backlogged, sometimes my E-mail crashes, and sometimes my literature search software crashes. If you've not heard from me in a week, post me again. I send my most challenging questions to the medical student pathology interest group, minus the name, but with your E-mail where you can receive a reply.

Numbers in {curly braces} are from the magnificent Slice of Life videodisk. No medical student should be without access to this wonderful resource.

I am presently adding clickable links to images in these notes. Let me know about good online sources in addition to these:

Freely have you received, freely give. -- Matthew 10:8. My site receives an enormous amount of traffic, and I'm still handling dozens of requests for information weekly, all as a public service.

Pathology's modern founder, Rudolf Virchow M.D., left a legacy of realism and social conscience for the discipline. I am a mainstream Christian, a man of science, and a proponent of common sense and common kindness. I am an outspoken enemy of all the make-believe and bunk that interfere with peoples' health, reasonable freedom, and happiness. I talk and write straight, and without apology.

Throughout these notes, I am speaking only for myself, and not for any employer, organization, or associate.

Special thanks to my friend and colleague, Charles Wheeler M.D., pathologist and former Kansas City mayor. Thanks also to the real Patch Adams M.D., who wrote me encouragement when we were both beginning our unusual medical careers.

If you're a private individual who's enjoyed this site, and want to say, "Thank you, Ed!", then what I'd like best is a contribution to the Episcopalian home for abandoned, neglected, and abused kids in Nevada:

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Especially if you're looking for information on a disease with a name that you know, here are a couple of great places for you to go right now and use Medline, which will allow you to find every relevant current scientific publication. You owe it to yourself to learn to use this invaluable internet resource. Not only will you find some information immediately, but you'll have references to journal articles that you can obtain by interlibrary loan, plus the names of the world's foremost experts and their institutions.

Alternative (complementary) medicine has made real progress since my generally-unfavorable 1983 review. If you are interested in complementary medicine, then I would urge you to visit my new Alternative Medicine page. If you are looking for something on complementary medicine, please go first to the American Association of Naturopathic Physicians. And for your enjoyment... here are some of my old pathology exams for medical school undergraduates.

I cannot examine every claim that my correspondents share with me. Sometimes the independent thinkers prove to be correct, and paradigms shift as a result. You also know that extraordinary claims require extraordinary evidence. When a discovery proves to square with the observable world, scientists make reputations by confirming it, and corporations are soon making profits from it. When a decades-old claim by a "persecuted genius" finds no acceptance from mainstream science, it probably failed some basic experimental tests designed to eliminate self-deception. If you ask me about something like this, I will simply invite you to do some tests yourself, perhaps as a high-school science project. Who knows? Perhaps it'll be you who makes the next great discovery!

Our world is full of people who have found peace, fulfillment, and friendship by suspending their own reasoning and simply accepting a single authority that seems wise and good. I've learned that they leave the movements when, and only when, they discover they have been maliciously deceived. In the meantime, nothing that I can say or do will convince such people that I am a decent human being. I no longer answer my crank mail.

This site is my hobby, and I do not accept donations, though I appreciate those who have offered to help.

During the eighteen years my site has been online, it's proved to be one of the most popular of all internet sites for undergraduate physician and allied-health education. It is so well-known that I'm not worried about borrowers. I never refuse requests from colleagues for permission to adapt or duplicate it for their own courses... and many do. So, fellow-teachers, help yourselves. Don't sell it for a profit, don't use it for a bad purpose, and at some time in your course, mention me as author and William Carey as my institution. Drop me a note about your successes. And special thanks to everyone who's helped and encouraged me, and especially the people at William Carey for making it still possible, and my teaching assistants over the years.

Whatever you're looking for on the web, I hope you find it, here or elsewhere. Health and friendship!


More of Ed's Notes: Ed's Medical Terminology Page

Perspectives on Disease
Cell Injury and Death
Accumulations and Deposits
What is Cancer?
Cancer: Causes and Effects
Immune Injury
Other Immune
HIV infections
The Anti-Immunization Activists
Infancy and Childhood
Environmental Lung Disease
Violence, Accidents, Poisoning
Red Cells
White Cells
Oral Cavity
GI Tract
Pancreas (including Diabetes)
Adrenal and Thymus
Nervous System
Lab Profiling
Blood Component Therapy
Serum Proteins
Renal Function Tests
Adrenal Testing
Arthritis Labs
Glucose Testing
Liver Testing
Spinal Fluid
Lab Problem
Alternative Medicine (current)
Preventing "F"'s: For Teachers!
Medical Dictionary

Courtesy of CancerWEB

Learning Objectives

Review the major players in the immune system, both cellular and humoral. Be sure you can explain what a hapten is.

For each of the following, describe the essential mechanism and mention some real-life illustrations: Type I, Type II, Type III, and Type IV hypersensitivity injury.

Briefly describe each of the following:

Describe and recognize the various anatomic signs of transplant rejection and graft versus host disease.

Critique the following statement, overheard at a party: "By strengthening our immune system, we prevent or cure most diseases. We strengthen our immune system by nutritional supplements and mental imagery to reduce stress."

Immune Disease
Iowa Virtual Microscopy
Have fun

Immune Pathology
Photos, explanations, and quiz
Indiana U.

KCUMB Students
"Big Robbins" -- Immuno
Lectures follow Textbook



HAPTENS are atoms or small molecules that elicit an immune response when, and only when, they are bound to a larger carrier molecule, generally a protein. The body's rejection of the hapten-protein adduct does the damage. Some famous examples are:


{14252} lymphocytes
{14720} lymphocyte
{14716} lymphocyte, large (i.e., a little bit turned-on)
{14718} lymphocyte, small (i.e., resting)
{16197} lymphocyte, small
{26001} lymphocytes in sputum
{26226} lymphocyte and neutrophil
{39919} lymphocytes (there's also a nice plasma cell right at the center)

Osmosis Jones

{46429} plasma cell, electron micrograph

{08230} macrophage containing leishmania (Baghdad boil)

{09205} mast cell granules (electron micrograph)
{13733} mast cells
{14539} mast cells (purple ones) and fibroblasts
{14542} mast cell degranulating
{15117} mast cell city!
{46472} mast cell, electron micrograph, intact
{46473} mast cell, electron micrograph, degranulating

{09207} eosinophil granules
{14099} eosinophils
{14708} eosinophil

IMMUNOGLOBULINS and COMPLEMENT should be familiar to you. For a pathologist's perspective on complement today, see Am. J. Path. 171: 715, 2008.



Local anaphylaxis: more often a nuisance than a real danger

{09716} urticaria
{09719} urticaria
{09720} urticaria; this is a variant with pressure-sensitive mast cells ("dermographism")
{12238} urticaria
{12240} urticaria
{25474} urticaria

{08161} atopic dermatitis ("eczema")
{12301} atopic dermatitis ("eczema"); this was probably contact dermatitis

Allergic to packed red cells
Pittsburgh Pathology Cases


Lewis A antibody
Pittsburgh Pathology Cases

Transfusion reaction
Pittsburgh Pathology Cases

{00049} Goodpasture's, immunofluorescent view of antibody along glomerular basement membrane

Goodpasture's disease
Linear fluorescence
WebPath photo


Lupus kidney
Antibodies deposited in glomerulus
Urbana Atlas of Pathology


{24955} dermatologist skin test; the guy was allergic to the ramrod (no, I don't know how it happened or what it was made of)


Transplant Immunology
Great site
Transplant Pathology Internet Services

Renal allograft rejection
Pittsburgh Pathology Cases

Acute transplant rejection
Vessel changes
KU Collection

Acute rejection
WebPath photo

Acute rejection
WebPath photo

Acute rejection
Antigen-antibody complexes
WebPath photo

Acute rejection
WebPath photo

Acute rejection
Immune complexes
WebPath photo

Acute rejection
WebPath photo

Chronic rejection
WebPath photo

Chronic rejection
WebPath photo


{12006} graft vs. host, skin lesions
{12007} graft vs. host, skin lesions

Graft vs. Host in the lung
Lung pathology series; follow the arrows
Dr. Warnock's Collection

Graft vs. host disease
Trust me; dead and dying cells
KU Collection

Graft vs. host disease
Trust me
KU Collection

Graft vs. host
Jaundice and rash
WebPath photo

Graft vs. host
Cloudy swelling and apoptosis
WebPath photo

Graft vs. host
Biliary scarring and obstruction
WebPath photo

Graft vs. host
Biliary scarring and obstruction
WebPath photo


* Sir Winston Churchill, in hospital with an infection during World War II, looked at his hospital chart and asked his physician, "What are these lymphocytes?" He was told: "We don't know, Prime Minster." "Then why do you count them?" Churchill retorted. Retold in Nature 333: 804, 1988.


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Teaching Pathology

Pathological Chess

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