Ed Friedlander, M.D., Pathologist

No texting or chat messages, please. Ordinary e-mails are welcome.

This website is certified by Health On the Net Foundation. Click to verify. This site complies with the HONcode standard for trustworthy health information:
verify here.

Search only trustworthy HONcode health websites:

Cyberfriends: The help you're looking for is probably here.

This website collects no information. If you e-mail me, neither your e-mail address nor any other information will ever be passed on to any third party, unless required by law.

This page was last modified January 1, 2016.

I have no sponsors and do not host paid advertisements. All external links are provided freely to sites that I believe my visitors will find helpful.

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.

I am active in HealthTap, which provides free medical guidance from your cell phone. There is also a fee site at

If you have a Second Life account, please visit my teammates and me at the Medical Examiner's office.

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:

I've spent time there and they are good. Write "Thanks Ed" on your check.

Help me help others

My home page
More of my notes
My medical students

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

Skin / Eye (?!)
Taiwanese pathology site
Good place to go to practice

Surgical Pathology Atlas
Nice photos, hard-core

Skin in Cinema

Tunisian Dermatopathology
Mostly in French
Great photos

Skin Pathology
Photomicrograph collection
In Portuguese

Skin Slides
Iowa Virtual Microscopy
Have fun

Dermatopathology Quizzes
Nice photos and explanations

Pathology of skin infections
Great site
Yutaka Tsutsumi MD

Italian dermatopathology
Great photomicrographs

Italian dermatopathology
Great photomicrographs

Skin Atlas
Dr. Dubin, from Israel
Great photos

From Johns Hopkins, really good
For more advanced learners

Skin Exhibit
Virtual Pathology Museum
University of Connecticut

Pathology of Biowarfare
Great review and photos,
including Saddam's old facility

Photos, explanations, and quiz
Indiana U.

Brown Digital Pathology
Some nice cases

Skin histopathology
Lots to see
Wikimedia Commons

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

QUIZBANK Skin (all)

For leprosy, click here.


Secondary syphilis

Yutaka Tsutsumi MD


      "No, I don't suffer from freckles," said Pippi.

      Then the lady understood but she took one look at Pippi and burst out, "But my dear child, your whole face is covered with freckles!"

      "I know it," said Pippi, "but I don't suffer from them. I love them. Good morning."

Pippi Longstocking
Pippi Longstocking

We're all of us sentenced to solitary confinement inside our own skins, for life!

Skin Tumors I
From Chile
In Spanish

Skin Tumors II
From Chile
In Spanish

Skin Tumors III
From Chile
In Spanish

Apocrine glands
From somebody's armpit
Photo by Ed

{11815} skin model
{00690} epidermis, histology
{11760} skin, histology

{12184} miliaria

SUNLIGHT AND THE SKIN (Postgrad. Med. 89(8): 59, June 1991; Am. Fam. Phys. 50: 32, 1994)

You do not beg the sun for mercy.


{25015} senile atrophy of the skin


Common ichthyosis
Prize photograph
Institute of Medical Illustrators

Ichthyosis "Collodion baby"
From a Saddam-era Iraqi
propaganda website (!)

Harlequin ichthyosis
Med student site

Harlequin ichthyosis
Med student site


{12183} vitiligo
{12474} vitiligo
{12489} vitiligo

    A patch of non-pigmented hair is "poliosis"; usually it is idiopathic though you may see it with various syndromes

URTICARIA ("hives"; Am. Fam. Phys. 83: 1078, 2011)

{09716} urticaria
{09717} urticaria
{09720} urticaria
{12241} dermographism

THE ECZEMA FAMILY (Postgrad. Med. 89(8): 75, June 1991)

Eczema family
From Chile
In Spanish

{12298} lichen simplex chronicus
{13114} lichen simplex chronicus

PHYTODERMATITIS ("fruit mask", "Club Med" dermatitis) results from the photosensitizing effects of psoralens (furocoumarins) from plants (limes, lemons and celery are notorious) on the skin. The term may also include allergic or toxic reactions to a variety of plants and their fluids.

Phytodermatitis from a lime on a cocktail
Juice dripped down onto her wrist
McGill Center for Tropical Disease


{08161} "eczema"
{12498} "eczema"
{24990} "eczema"
{12523} eczema secondary to photodermatitis
{12293} atopic dermatitis
{12294} atopic dermatitis
{12531} atopic dermatitis
{12534} atopic dermatitis, lichenified
{08160} contact dermatitis, hat band
{25581} she was allergic to her tincture of benzoin
{19349} contact dermatitis, earring
{12127} contact dermatitis
{12538} contact dermatitis, weepy
{12542} contact dermatitis, metal hapten
{12544} contact dermatitis, shoe
{12546} contact dermatitis, spray-on deodorant
{19358} contact dermatitis, balloon cells
{08154} poison ivy
{12562} nummular dermatitis

ERYTHEMA MULTIFORME ("EM"; Am. Fam. Phys. 46: 1171, 1992; Postgrad. Med. 107: 87, 2000)

{09698} erythema multiforme
{09699} erythema multiforme
{09701} erythema multiforme
{09702} erythema multiforme
{09704} erythema multiforme
{09705} erythema multiforme
{12261} erythema multiforme
{12516} erythema multiforme, vesicular
{12126}erythema multiforme bullosum
{12529} erythema multiforme, purpuric
{09710} bad erythema multiforme
{05943} Stevens-Johnson syndrome, skin
{05944} Stevens-Johnson syndrome, oral ("cheilitis")
{10304} toxic epidermal necrolysis
{09711} toxic epidermal necrolysis
{09713} toxic epidermal necrolysis

Pustular dermatitis
Prize photograph
Institute of Medical Illustrators

{13313} leukocytoclastic vasculitis
{12259} leukocytoclastic vasculitis, palpable purpura


From Chile
In Spanish

{12484} erythema nodosum

PSORIASIS (Madison Avenue's "heartbreak", etc.; Lancet 361: 1197, 2003; Lancet 370: 263, 2007)

{12264} psoriasis
{12574} psoriasis
{12576} psoriasis
{12579} psoriasis
{12580} psoriasis
{12582} psoriasis
{12585} psoriasis
{19367} psoriasis
{19370} psoriasis
{19385} psoriasis
{24875} psoriasis
{12475} psoriasis, Koebner phenomenon
{12513} exfoliative erythroderma, maybe psoriasis, maybe mycosis fungoides, maybe who-knows?

From Chile
In Spanish

LICHEN PLANUS (Am. Fam. Phys. 61: 3319, 2000; NEJM 366: 723, 2012)

{12280} lichen planus
{12476} lichen planus
{12591} lichen planus
{12592} lichen planus
{12597} lichen planus
{12600} lichen planus
{12601} lichen planus
{12591} lichen planus
{12604} lichen planus, filigree lesions in mouth

Lichen Planus
From Chile
In Spanish


{12188} lichen sclerosus et atrophicus
{24988} lichen sclerosus et atrophicus

DISCOID LUPUS: Very common

{12273} discoid lupus
{25674} discoid lupus
{25676} discoid lupus
{12324} alopecia secondary to discoid lupus

ACNE VULGARIS (Lancet 379: 361, 2012)

Comedone nevus
Prize photograph
Institute of Medical Illustrators

{09722} acne
{09725} acne
{12144} acne
{12145} acne
{24919} acne, face; your lecturer age 13
{24981} acne, blackhead city
{12495} acne, closed and open comedones
{12148} acne, open comedone, world's largest blackhead
{12221} acne, open comedone, world's second largest blackhead
{25672} histology of the comedone!
{25673} histology of the comedone!

{12149} acne rosacea
{09728} acne rosacea

* SEBACEOUS HYPERPLASIA refers to the common multiple soft, yellowish, slightly-raised spots seen on the noses, foreheads, and cheeks of many pregnant women, babies, older folks, and cyclosporine takers. Look hard and you'll find it on

PEMPHIGUS VULGARIS (Lancet 354: 667, 1999) and the other blistering disorders

{12123} pemphigus vulgaris
{12124} pemphigus vulgaris
{12651} pemphigus vulgaris
{12657} pemphigus vulgaris
{12658} pemphigus vulgaris

Immunofluorescence "chicken wire"
KU Collection

(BULLOUS) PEMPHIGOID (Lancet 381: 320, 2013)

{12125} pemphigoid
{12633} pemphigoid
{12634} pemphigoid
{12636} pemphigoid
{12637} pemphigoid
{12640} pemphigoid
{12643} pemphigoid, histology
{12644} pemphigoid, immunofluorescence (yellow)
{12694} cicatricial pemphigoid

POMPHOLYX ("dyshydrotic eczema") is a very common, banal, but annoying disease in which little blisters cover the palms and soles. A minor mystery of medicine, there's a link to nickel allergy (J. Derm. 19: 964, 1994; Cutis 47: 157, 1991), or other metal allergy, in people with sweaty palms.


    * Jean-Paul Marat, amateur scientist and quack doctor turned far-left-wing ideologue, was the French Revolution's first mass-murderer. His skin disease was intensely pruritic, blistering, began in the perianal region, and was associated with weight loss leading to emaciation. He was sick with it for the three years prior to his assassination, and spent most of this time in his bathtub. My choice is dermatitis herpetiformis. Another pathologist agrees: Am. J. Dermpath. 1: 251, 1979.

    And now you sit in your bathtub, testing the validity of the proposition, "The more you scratch, the more you itch."

          -- Marat-Sade


{12122} dermatitis herpetiformis
{12663} dermatitis herpetiformis
{12524} dermatitis herpetiformis, eczematized
{12672} dermatitis herpetiformis, immunofluorescence for IgA


Epidermolysis Bullosa

WARTS ("verrucae")

{08203} warts
{12138} wart
{24894} wart
{08983} wart, histology
{08986} wart, histology
{12164} condyloma acuminata

HPV-1 myrmecia
Advanced students
Yutaka Tsutsumi MD

Verruca plana
Yutaka Tsutsumi MD

Plantar wart
Yutaka Tsutsumi MD


{08205} molluscum contagiosum
{12174} molluscum contagiosum
{12175} molluscum contagiosum
{24730} molluscum contagiosum
{24731} molluscum contagiosum

Molluscum Contagiosum
Electron micrographs
VCU Pathology

PITYRIASIS ROSEA (Am. Fam. Phys. 69: 87, 2004)

Pityriasis rosea
Patient photo
Thanks Brian!

{12279} pityriasis rosea
{12487} pityriasis rosea
{12610} pityriasis rosea
{12616} pityriasis rosea


{24970} impetigo
{24971} impetigo
{24972} impetigo
{24973} impetigo
{12128} impetigo, bullous

Staph impetigo

Yutaka Tsutsumi MD

NECROTIZING FASCIITIS ("flesh-eating strep" Science 264: 1665, 1994; MRSA NEJM 352: 1445, 2005; update JAMA 299: 79, 2008)

* FACTITIOUS DERMATITIS ("dermatitis artefacta") is self-inflicted and usually obvious enough to a skilled physician. English beggars actually had a technology ("cleymes") to cause horrid-appearing sores; they would use a mix of calcium salts, soap, iron rust, and sometimes arsenic under an occlusive dressing.

* "Morgellon's disease", in which patients say they see horrid little worms coming out of their skin lesions, which otherwise look like they result from scratching, remains a mystery (Nat. Med. 12: 982, 2006). Patients bring in pieces of lint, skin, or hair as proof ("matchbox sign"; Mayo Clin. Proc. 79: 1470, 2004); so far, they have never withstood examination by pathologists. A lone report of identification of the structures as nematodes or something similar remains unconfirmed. Click here for a 2004 article claiming to find collembola springtails. Nothing since, and if it were true, the research piranhas would have confirmed it by now. Delusional parasitosis in an organic psychosis from medication: World J. Gastro. 13: 2379, 2007. Of course, cocaine is infamous for producing the sensating of critters crawling under your skin ("the cocaine bug"; update J. Am. Acad. Derm. 59: 483, 2008). The drug pimozide seems to work better than the others; there's talk about a specific dopamine problem (Med. Hypoth. 68: 1351, 2007).

* PITTED KERATOLYSIS is a corynebacterial infection of macerated super-thick keratin on the soles of the feet, especially in people who go barefoot or wear wet shoes or have super-tight boots. It looks warty and smells like decomposition.



HIDRADENITIS SUPPURATIVA ("acne inversa"; NEJM 366: 158, 2012)

{12230} hidradenitis suppurativa, vulva

SUPERFICIAL FUNGI ("dermatophytes")

{12499} seborrheic dermatitis
{12565} seborrheic dermatitis
{12571} seborrheic dermatitis

{12348} candida paronychia
{14238} candida, penis
{12507} candida exacerbating intertrigo
{08163} moniliasis of skin ("diaper rash")

{14234} tinea capitis ("ringworm of the scalp")
{08148} tinea pedis ("athlete's foot")
{12268} tinea pedis
{14227} tinea pedis
{12270} tinea cruris ("crotch-rot")
{12477} tinea corporis ("ringworm of the body")
{14221} tinea corporis
{14223} tinea corporis, leg
{08149} ringworm, id reaction
{08152} more ringworm
{12625} pityriasis rubra pilaris (mysterious disease that simulates ringworm)

{12182} tinea versicolor
{12505} tinea versicolor
{12519} tinea versicolor
{14247} tinea versicolor
{14250} tinea versicolor

Pityrosporum, KOH prep
from a doctor buddy with
folliculitis of his beard area

Malassezial folliculitis

Yutaka Tsutsumi MD


{09753} scabies
{43077} scabies
{43079} scabies mite
{24872} scabies

{12222} bug bites

Demodex folliculorum
Yutaka Tsutsumi MD

Botfly video
Human myiasis from Panama
Educational, some profanity


{12327} alopecia areata

{12328} trichotillomania

THE SKIN TUMORS, both malignant and premalignant (i.e., the ones we care about) are often discovered unexpectedly when the doctor sees you for something else.

FRECKLES ("ephelides", singular is "ephelis")

{12191} ephelis

MELASMA ("raccoon eyes", "mask of pregnancy")

LENTIGINES (singular is "lentigo")

Some CAFÉ AU LAIT SPOTS (better, "melanotic macules") look like freckles under the microscope, but are usually single and larger. These lesions are homogeneously pigmented and present at birth. Despite their usefulness in confirming your clinical suspicions of neurofibromatosis ("coast of California" -- these may contain giant melanosomes) or McCune-Albright's ("coast of Maine"), several percent of normal people have at least one little one.

{09645} lentigo city! ("old age spots")
{09647} lentigo
{09648} lentigo
{12192} lentigines
{12525} lentigo city

NEVOCELLULAR NEVI ("pigmented nevi", "melanocytic nevi", "moles"; single is "nevus")

{09636} melanocytic nevus, gross
{09638} melanocytic nevus, gross
{12177} melanocytic nevus, gross; this was intradermal
{12194} melanocytic nevus, gross; this was compound
{12195} melanocytic nevus, gross; this was intradermal
{08150} intradermal nevus, histology
{08153} intradermal nevus, histology
{25680} junctional nevus with melanophages
{25681} junctional nevus with melanophages
{08156} nevus cells

Intradermal nevus
Great labels
Romanian Pathology Atlas

WebPath Photo

{09650} nevus spilus
{09651} nevus spilus
{09653} nevus spilus
{09656} nevus spilus

    BECKER'S NEVUS ("Becker's hypermelanosis") is a big, dark, extra-hairy (usually) patch that usually appears on a man's upper back or shoulder (occasionally elsewhere) at puberty. There are also extra arrector pili muscles, sometimes enough to make the region extra-firm. Common, and sometimes hereditary. Keep an eye on it (slight melanoma risk, just remove the melanomas in a timely way before they get dangerous -- Dermatologica 182: 77, 1991), and reassure the owner that a Becker's nevus is very macho and studly.

      * Richard Gere has one, which he does not cover with makeup during his love scenes.

      * Sometimes the affected region also features hypoplasia of arm and/or breast, scoliosis, lots of little skin leiomyomas, and/or spina bifida occulta (Am. J. Med. Genet. 68: 357, 1997). This is only a small minority of Becker's people, but is called "Becker's nevus syndrome."

{09659} Becker's nevus

Becker's Nevus
Richard Gere in "Breathless"
Becker's Nevus
Richard Gere in
"An Officer and a Gentleman"

Becker's Nevus
Richard Gere in "American Gigolo"
Heath Ledger
What do you think?

{24902} blue nevus, trust me, this was deep-deep in the dermis.

{09639} halo nevi, gross
{09641} halo nevus, gross
{09642} halo nevus, gross

{12204} giant congenital pigmented nevus
{24625} giant congenital pigmented nevus

{24903} hairy nevus, congenital
{24904} hairy nevus, congenital
{25108} compound nevus, histology

DYSPLASTIC NEVI ("BK moles", etc.; Clin. Lab. Med. 31: 255, 2011)

{12196} dysplastic nevus
{12197} dysplastic nevus
{09663} dysplastic nevus

MALIGNANT MELANOMA ("malignant mole", "black mole cancer"): Am. Fam. Phys. 63: 1359, 2001; Surg. Clin. N.A. 83: 77, 2003; melanoma atlas Cancer 94: 3192, 2002; Lancet 365: 687, 2005; Mayo Clin. Proc. 82: 364, 2007; CA 60: 301, 2010; Am. Fam. Phys. 85: 161, 2012.

Lentigo maligna
Pittsburgh Pathology Cases

Lentigo Maligna
Pittsburgh Illustrated Case

Malignant Melanoma
Australian Pathology Museum
High-tech gross photos

Malignant Melanoma
Text and photomicrographs. Nice.
Human Pathology Digital Image Gallery

Electron micrographs
VCU Pathology

{09683} melanoma, gross
{09684} melanoma, gross
{09687} melanoma, gross
{09689} melanoma, gross
{09690} melanoma, gross
{09692} melanoma, gross
{09695} melanoma, gross
{09098} melanoma, gross, amelanotic (i.e., this one makes no melanin)
{09099} melanoma, gross, amelanotic
{24916} melanoma, gross
{24741} superficial spreading melanoma, vertical growth phase
{10940} superficial spreading melanoma, gross
{12198} superficial spreading melanoma, gross
{24914} superficial spreading melanoma, vertical
{24915} superficial spreading melanoma, vertical growth phase
{25601} superficial spreading melanoma
{12199} nodular melanoma
{25516} nodular melanoma
{25600} nodular melanoma
{24911} spindle cell melanoma
{12200} lentigo maligna
{24912} lentigo maligna
{24913} lentigo maligna
{13121} lentigo maligna
{13122} melanoma
{13123} melanoma
{13306} melanoma
{13307} melanoma
{13308} melanoma
{15400} melanoma, electron micrograph showing melanosomes
{13309} superficial spreading melanoma
{13310} superficial spreading melanoma
{12201} acral lentigenous melanoma
{08967} invasive malignant melanoma
{08968} invasive malignant melanoma
{08969} invasive malignant melanoma
{10546} melanoma, metastatic in liver
{08035} melanoma, metastatic in heart

Tom Demark's Site

Melanoma metastases
Only one side of the body is involved
New England Journal of Medicine

Metastatic Melanoma, Lung
Text and photomicrographs. Nice.
Human Pathology Digital Image Gallery

Superficial spreader
Wikimedia Commons

Wikimedia Commons

NEVUS SEBACEUS ("nevus sebaceous") is a common, often large congenital hamartoma (skin, hair, big sebaceous glands, apocrine glands), usually on the hairline on the temple. It looks like skin, but with a bumpy surface and often less hair than usual. There are syndromes with very large lesions. There is much controversy about the rate of malignancy, but the tendency nowadays is to excise them.

SEBORRHEIC KERATOSIS (* "basal cell papillomas", * "barnacles")

{12502} seborrheic keratosis
{12765} seborrheic keratosis
{25496} seborrheic keratosis
{24895} seborrheic keratosis, histology
{24896} seborrheic keratosis, histology
{12771} seborrheic keratoses, think of Leser-Trelat

Seborrheic keratosis
Horn cysts


{25607} acanthosis nigricans
{25608} acanthosis nigricans

FIBROEPITHELIAL POLYPS ("acrochordons", "skin tags", "squamous papillomas", etc., etc.)

{12176} acrochordon
{12780} acrochordons
{12781} acrochordons
{12206} brown skin tag

Squamous Cell Papilloma
Ignore the text -- this one
is not an HPV-related lesion

{25116} Fabry's

EPITHELIAL CYSTS ("epidermoid inclusion cysts"; "wens"; "sebaceous cysts")

{12170} epidermoid inclusion cyst, shoulder
{10310} epidermoid inclusion cyst
{12504} epidermoid inclusion cyst


{12792} keratoacanthoma
{12795} keratoacanthoma
{12799} keratoacanthoma
{24892} keratoacanthoma, histology
{24893} keratoacanthoma, histology

Prize photograph
Institute of Medical Illustrators

Eye pathology site

Wikimedia Commons

SKIN ADNEXAL TUMORS ("appendage tumors"): A bewildering family of minor skin tumors.

{25595} cylindromas ("turban tumor")
{25596} cylindromas

{10307} syringoma

{11767} trichoepithelioma
{11788} trichofolliculoma

{11806} trichilemmoma

{24888} hidradenoma
{24889} hidradenoma
{24920} calcifying epithelioma of Malherbe ("pilomatrixoma")

ACTINIC KERATOSIS (review Am. Fam. Phys. 49: 817, 1994)

Skin horn
Source unknown
Not for young or sensitive visitors.

Skin horn
Source unknown
Not for young or sensitive visitors.

{12736} actinic keratosis
{12738} actinic keratosis
{25506} actinic keratosis

Simpsons character

Bowen disease
Wikimedia Commons

SQUAMOUS CELL CARCINOMA (Plast. Recon. Surg. 114: 82e, 2004; molecular pathways J. Cln. Inv. 122: 464, 2012)

{12735} squamous cell carcinoma
{12733} neglected squamous cell carcinoma
{21858} squamous cell carcinoma
{21859} squamous cell carcinoma of eye
{12169} squamous cell CA, lip

Squamous cell carcinoma of skin
Great labels
Romanian Pathology Atlas

Squamous Cell Carcinoma
Text and photomicrographs. Nice.
Human Pathology Digital Image Gallery

Squamous cell carcinoma
Eye pathology site

    You remember XERODERMA PIGMENTOSUM, a heterogeneous (Am. J. Hum. Genet. 54: 191, 1994) family of hereditary diseases in which the body has difficulty repairing actinic (and probably other) damage to DNA. Most common gene: Arch. Derm. 128: 971, 1992; the family Arch. Derm. 128: 1233, 1992.
The Others
The Others

{25012} xeroderma pigmentosum


Basal cell carcinoma of skin
Great labels
Romanian Pathology Atlas

Basal cell carcinoma
Eye pathology site

Basal Cell Carcinomas
Nice photomicrograph
Thanks Indigo

Basal Cell Carcinoma
John Hendrix MD
Wikimedia Commons

Basal Cell Carcinoma
Text and photomicrographs. Nice.
Human Pathology Digital Image Gallery

Basal cell carcinoma
Pearly and vascular
Wikimedia Commons

Basal cell carcinoma
Early invasion
Wikimedia Commons

{12168} basal cell carcinoma, gross
{12706} basal cell carcinoma
{12711} basal cell carcinoma
{12714} basal cell carcinoma
{12723} basal cell carcinoma
{21847} basal cell carcinoma
{21850} basal cell carcinoma, histology
{21856} basal cell carcinoma, histology, sclerosing variant with desmoplasia

Basal cell carcinoma
Arising off a hair shaft

Nevoid basal cell carcinoma syndrome
Pittsburgh Pathology Cases

MERKEL CELL CARCINOMA (neuroendocrine skin cancer; Cancer 88: 1842, 2000; Am. J. Clin. Path. 115 S: S 68, 2001; Cancer 110: 1, 2007; Cancer 113: 2549, 2008; Arch. Path. Lab. Med. 134: 1711, 2010; Barnes series Ann. Surg. 254: 465, 2011)

Merkel Cell Carcioma
Electron micrographs
VCU Pathology

BENIGN CUTANEOUS FIBROUS HISTIOCYTOMA ("dermatofibroma", "sclerosing hemangioma")

{12203} dermatofibroma
{12772} dermatofibroma
{12774} dermatofibroma
{12775} dermatofibroma
{12777} dermatofibroma
{25593} dermatofibroma

XANTHOMAS ("xanth-" means "yellow", "-oma" here means "bump")

{09741} xanthomas
{09744} xanthomas
{12219} xanthoma
{24886} xanthoma

{05937} pseudoxanthoma elasticum

VASCULAR LESIONS: We examined these in other sections.

{12510} cherry angiomas
{05926} spider angioma
{05928} spider angiomas
{12235} hemangioma
{12237} Kasabach-Merritt hemangioma

Kaposi's sarcoma
AIDS patient
KU Collection

Kaposi's sarcoma in AIDS

Yutaka Tsutsumi MD


{09041} mycosis fungoides
{12754} mycosis fungoides
{12751} mycosis fungoides, tumor stage
{12757} mycosis fungoides (this was a Sezary case)
{12759} mycosis fungoides, Pautrier micro-abscess
{09042} mycosis fungoides, convoluted T-cell as seen on electron microscopy

MASTOCYTOSIS -- obscure enough to save for your clinical rotations, or the hematology section of your classroom time. Update Am. J. Clin. Path. 138: 416, 2012.


{08157} fifth disease
{08158} fifth disease
{08167} erythema chronicum migrans
{08170} heroin tracks
{08199} yaws, skin disease
{08200} yaws, skin disease
{08389} cutaneous larva migrans
{08393} leishmaniasis
{09734} pyoderma gangrenosum
{09737} pyoderma gangrenosum
{09738} pyoderma gangrenosum
{10067} abscess
{10081} squamous cell carcinoma, keratin pearl
{12215} amyloid of the skin
{12229} erysipelas, strep infection
{12486} squamous cell carcinoma
{12513} exfoliative erythroderma
{12523} photodermatitis
{12805} keloid
{13120} dermatomyositis, Gottron's sign
{13338} herpes, skin
{13343} leprosy
{14145} herpes zoster
{14146} herpes zoster
{14148} herpes zoster
{14200} folliculitis. ERF had this ages 11-17, probably tinea versicolor folliculitis.
{14202} folliculitis, ditto
{24917} scleroderma, skin
{12226} granuloma annulare
{24918} granuloma annulare
{24923} blastomycosis, skin
{24933} histology of chicken pox
{53760} linear nevus sebaceus (nevus sebaceous)

Larva migrans
Creeping eruption
Yutaka Tsutsumi MD

Tuberculosis of skin

Yutaka Tsutsumi MD

Madura foot

Yutaka Tsutsumi MD

Leishmania tropica
Cutaneous leishmaniasis
Yutaka Tsutsumi MD

Actinomycosis of skin

Yutaka Tsutsumi MD

* Pseudoscience: During the 1990's, an elaborate mythology about melanin (as the essence of human intelligence, a superconductor, the source of psychic powers, etc., etc.) has been promoted. There are "melanin conferences", etc. It's obvious to any real scientist or thinking physician that this is simply a crooked way to make money. Ironically, until recently, U.S. minorities were traditional victims of the same caliber of racist pseudoscience. Stay tuned, this business isn't funny.


{12189} balanitis xerotica
{12190} tuberous sclerosis ash-leaf spots
{12169} squamous cell CA, lip
{12214} necrobiosis lipoidica diabeticorum
{12226} granuloma annulare
{12227} furuncle
{12230} hidradenitis suppurativa, vulva
{5926} spider angioma
{5928} spider angioma
{12235} hemangioma
{12237} Kasabach-Merritt hemangioma
{12274} lupus, butterfly rash
{12292} measles (rubeola)
{12337} clubbing
{12305} abetalipoproteinemia, RBC's ("ET-finger cells")
{12668} nutmeg liver
{12762} Kaposi's
{12801} scar
{12807} keloid
{13053} granuloma annulare, gross
{13120} dermatomyositis, Gottron's sign
{13338} herpes, skin
{13343} leprosy
{12786} pyogenic granuloma
{12789} pyogenic granuloma
{12805} keloid
{13613} amyloid vessel, H&E
{13392} cystic hygroma
{13370} flea-bitten kidneys
{14137} varicella
{18250} phenylketonuria
{18253} phenylketonuria
{19377} melanoma of the eye
{21859} squamous cell carcinoma of eye
{24626} scleroderma, hands
{24854} hyperplastic arteriolar sclerosis in scleroderma
{24917} scleroderma, skin
{24918} granuloma annulare
{24923} blastomycosis, skin
{24933} histology of chicken pox
{25116} Fabry's
{25024} fatty streaks
{25675} lupus, butterfly rash


If your browser were java-capable, you could see my skin here. 11760 skin, normal
11761 skin, normal
14788 skin, thick
14789 skin, thick
14790 melanin in the skin, normal
14791 melanin in the skin, normal
14792 skin, thick
14793 skin, thick
14794 skin, thick
14795 skin, thick
14796 sebaceous gland, normal
14797 sebaceous gland, normal
14798 dermal papilla, normal
14799 dermal papilla, norma
14800 meissner's corpuscle
14801 meissner's corpuscle
15092 skin, normal
15093 skin, normal
15305 skin, thin
15306 skin, thin
15307 skin, thin
15308 skin, thin
15309 skin, thin
15310 skin, thin
15311 skin, thin
15313 skin, thick
15315 skin, stratum corneum and lucida
20914 skin
20916 skin, eccrine gland
20917 sebaceous gland, skin
20918 skin, thick
20919 skin, thick
20920 skin, thick
20921 skin, thick
20922 pacinian corpuscle, skin
20923 skin, thick
24860 skin, normal
25083 skin, normal
25084 skin, normal epidermis

Prayer Request

Ed's Autopsy Page
The Pathology Blues
Ed's Pathology Review for USMLE I

PathMax -- Shawn E. Cowper MD's pathology education links


New visitors to
reset Jan. 30, 2005:

Ed at homeDrop by and meet Ed

Ed says, "This world would be a sorry place if people like me who call ourselves Christians didn't try to act as good as other good people ." Prayer Request

If you have a Second Life account, please visit my teammates and me at the Medical Examiner's office.

Teaching Pathology

Pathological Chess

Taser Video
83.4 MB
7:26 min
Click here to see the author prove you can have fun skydiving without being world-class.

Click here to see the author's friend, Dr. Ken Savage, do it right.