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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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.

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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.

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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!

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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

Taiwanese pathology site
Good place to go to practice

Photo Library of Pathology
U. of Tokushima

Mediastinum (Thymus)
Photo Library of Pathology
U. of Tokushima

Iowa Virtual Microscopy
Have fun

Utah cases for path students
Juliana Szakacs MD

Adrenal Exhibit
Virtual Pathology Museum
University of Connecticut

Photos, explanations, and quiz
Indiana U.

Nice case photos
Charam M. Ramnani MD

Brown Digital Pathology
Some nice cases

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



Mention the normal gross and microscopic anatomy of the adrenal glands, parathyroid glands, and thymus gland. Describe their origins within individuals, and their functions.

Define hypoadrenocorticism, mention the etiologies of the chronic and acute forms, and tell what each looks like clinically. Explain hyperpigmentation in some of these patients, and tell why they are at risk for sudden death.

Describe the etiologies of Cushing's syndrome, from the most to the least common. Tell what symptoms and signs should alert you, the physician, to the possibility of Cushingism. Explain Nelson's syndrome, and why it is becoming uncommon.

Define primary hyperaldosteronism and Conn's syndrome. Distinguish these from secondary hyperaldosteronism. Tell what symptoms and signs point to excess aldosterone, and explain the danger of treating these patients with "safe" diuretics.

Describe in detail the pathogenesis of congenital adrenal hyperplasia, and distinguish the most common salt-retaining and the most common salt-wasting form. Describe the forme fruste that we now believe is very common.

Describe the behavior of carcinomas of the adrenal cortex.

Discuss pheochromocytoma and neuroblastoma with respect to their names, locations, etiologies, catecholamine production, gross and microscopic appearances, clinical picture, and prognosis. Mention the "primitive neuroectodermal tumors" that look like neuroblastomas, and describe "spontaneous cures" of neuroblastoma. Provide an educated guess of how many of your classmates had a "neuroblastoma" at birth.

Describe in some depth the prevalence, etiologies, symptoms, signs and treatment of hyperparathyroidism. Explain how to tell parathyroid hyperplasia from parathyroid adenoma, and why anyone cares. Describe how and when hypoparathyroidism develops, why it is serious, and how to recognize it.

Describe how the size of the thymus gland changes with age. Define thymic hyperplasia and thymoma, tell what they look like, and mention the diseases with which they are associated.

List the components of the important anti-oncogene deletion syndromes MEN I, IIa, and IIb.


Adrenal gland
"Pathology Outlines"
Nat Pernick MD, great site

Adrenal Histology
Ed's Histology Notes

Normal adrenal
Find it!
WebPath Photo

Adrenal histology
Point and click
WebPath Photo

Normal adrenals

WebPath Photo

Normal adrenals

WebPath Photo

One surprising fact about the adrenal gland is that, unlike many other organs, masses found here are seldom biopsied prior to excision. The radiology team will advise surgeons whether to remove particular masses. The one exception is biopsy to confirm metastatic disease in someone with a known cancer, usually in the lung (Arch. Surg. 144: 465, 2009).

THE ADRENAL CORTEX: "An organ essential to life." Pathology of the adrenal cortex: Arch. Path. Lab. Med. 132: 1263, 2008.

{11204}      adrenal and its nerve, normal
{11207}      adrenal and its nerve, normal
{11210}      adrenal and its nerve, histology, normal
{15035}      normal adrenal gland, showing zones (can you figure them out?)

Androstenedione (?)

{49431}      hyperplasia of adrenal cortex, etiology undisclosed
{09217}      adrenal cortical hyperplasia, etiology unknown


Adrenal -- cytomegalic fetal cortex
Beckwith-Wiedemann, a poorly-understood
genetic illness. Wikimedia Commons

ECTOPIC ADRENAL CORTICAL TISSUE (sometimes ectopic adrenal medulla too)

HYPOADRENOCORTICISM ("Addisonism", etc.): Insufficient glucocorticoid (and usually insufficient mineralocorticoid) production. Reviews Lancet 361: 1881, 2003; NEJM 360: 2328, 2009.

{09223}      adrenal tuberculosis, gross
{25399}      tuberculosis of adrenal, histology
{27257}      tuberculosis of adrenal, histology

Adrenal atrophy in
treated addisonism

TB of the adrenal

WebPath Photo

{25394}      adrenal cortical atrophy (key says "hypoplasia", I doubt this)
{24607}      adrenal amyloidosis, gross
{15960}      cytomegalic inclusion disease, adrenal
{37216}      adrenal leukodystrophy ("Lorenzo's oil") case, gross brain
{37218}      adrenal leukodystrophy case, gross brain
{37221}      adrenal leukodystrophy case, histology brain
{37224}      adrenal leukodystrophy case, gross adrenal
{37225}      adrenal leukodystrophy case, histology adrenal

Adrenal amyloidosis

WebPath Photo

Atrophic, normal, hyperplastic
WebPath Photo

{09371}      Addison's disease; pigmentation and vitiligo (mother and daughter)
{09372}      Addison's disease, face
{09373}      Addison's disease, buccal pigmentation
{49438}      Addison's disease, pigmentation
{49439}      Addison's disease, pigmentation
{49440}      Addison's disease, atrophy of the adrenal gland

{24606}      Waterhouse-Friderichsen adrenal, gross
{09224}      adrenal hemorrhage, consistent with Waterhouse Friderichsen
{07570}      adrenal hemorrhage, gross, consistent with Waterhouse-Friderichsen syndrome

Patient photo
WebPath Photo

Cortex blood / necrotic, medulla (blue) spared


WebPath Photo


WebPath Photo

CUSHING'S SYNDROME: too much glucocorticoid. Review NEJM 332: 791, 1995.

{49441}      looks like an oat cell case; adrenal cortex is hyperplastic, and bears a metastasis

Both Cushing's disease and glucocorticoid-secreting adenomas are most common in women ages 15 to 45, but can hit anybody, anytime. (* Cushingism in kids and teens: NEJM 331: 629, 1994).

Symptoms and signs that should alert you to possible Cushingism:

{09367}      Cushingism, face
{09370}      Cushingism, face
{16109}      Cushing's syndrome
{16110}      Cushing's syndrome
{16112}      Cushing's syndrome "before"
{16111}      Cushing's syndrome "after"
{49426}      Cushingism, 40 y/o patient
{49427}      Cushingism
{49428}      Cushingism, hyperplastic adrenal cortex

PRIMARY HYPERALDOSTERONISM ("low-renin hyperaldosteronism"): too much mineralocorticoid (review: Postgrad. Med. 95(4): 199, March 1994; NEJM 339: 1820, 1999; Lancet 353: 1341, 1999; Surg. Clin. N.A. 84: 887, 2004; Lancet 371: 1921, 2008)

CONGENITAL ADRENAL HYPERPLASIA: autosomal-recessive virilization syndromes that, in their most severe forms, affect young children.

{49437}      adrenogenital syndrome 2 year old girl
{24450}      adrenogenital syndrome, virilized baby girl
{49432}      11-hydroxylase deficiency, 11 month old boy


{09220}      adrenal cortical adenoma, gross
{20312}      adrenal cortical adenoma, gross
{49436}      adrenal cortical adenoma, gross; this one produced Conn's syndrome
{10298}      adrenal cortical adenoma
{20315}      adrenal cortical adenoma, histology
{09221}      adrenal cortical adenoma, histology
{09222}      adrenal cortical adenoma, histology
{08964}      adrenal cortical adenoma, histology (hard to tell from normal cortex)
{09052}      adrenal cortical adenoma, electron micrograph; note tubular cristae in mitochondria (spaghetti instead of lasagna)
{09375}      effect of masculinizing adrenal cortical adenoma, "before"
{09374}      effect of masculinizing adrenal cortical adenoma, "after"
{49434}      gynecomastia in five-year old boy, feminizing adrenal cortical adenoma

Adrenal cortical adenoma
This was a cushingoma
WebPath Photo

Adrenal cortical adenoma
Urbana Atlas of Pathology

Adrenal cortical adenoma
This was a connoma
WebPath Photo

Adrenal cortical adenoma

WebPath Photo

{25412}      adrenal myelolipoma, gross
{49443}      adrenal myelolipoma, gross
{25413}      adrenal myelolipoma, histology

Adrenal myelolipoma
Pittsburgh Pathology Cases

ADRENAL CORTICAL CARCINOMA (Am. J. Clin. Path. 105: 76, 1996; J. Urol. 169: 5, 2003; J. Clin. Endo. Metab. 95: 4812, 2010)

Adrenal cortical carcinoma
Pittsburgh Pathology Cases

Adrenal cortical carcinoma
Pittsburgh Pathology Cases

Adrenal cortical carcinoma

WebPath Photo

Adrenal cortical carcinoma

WebPath Photo

Adrenal cortical carcinoma

WebPath Photo

{24087}      adrenal cortical carcinoma, gross
{40196}      adrenal cortical carcinoma
{24090}      adrenal cortical carcinoma, histology

Metastatic cancer in the adrenals

WebPath Photo

Cancer metastatic to the adrenal
Wikimedia Commons

THE ADRENAL MEDULLA: "An organ not essential to life".

PHEOCHROMOCYTOMA ("paraganglioma", "pheo", formerly "ten percent tumor"; big NIH consensus review Ann. Int. Med. 134: 315, 2001; big review for pathologists Arch. Path. Lab. Med. 132: 1272, 2008).

{24716}      neuroblastoma, histology, good rosettes
{25420}      neuroblastoma, gross
{25422}      neuroblastoma, histology
{39049}      neuroblastoma, gross; probably an incidental finding in a newborn
{09009}      neuroblastoma, histology
{09232}      neuroblastoma, histology
{20046}      neuroblastoma, histology
{20047}      neuroblastoma, histology
{09011}      neuroblastoma, histology, good rosettes
{08963}      neuroblastoma histology (sorry, no good rosettes)
{25424}      ganglioneuroblastoma, histology
{25426}      ganglioneuroblastoma, histology
{24608}      ganglioneuroma, gross

Neuroblastoma rosette
Wikimedia Commons

Child with neuroblastoma
Wikimedia Commons


WebPath Photo


WebPath Photo

WebPath Photo

WebPath Photo

Neuroblastoma patient & family
Cindie and 10 y/o Derek Madsen
Pulitzer-Prize photoessay



Parathyroid Exhibit
Virtual Pathology Museum
University of Connecticut

"Pathology Outlines"
Nat Pernick MD

Normal parathyroid

WebPath Photo

Parathyroid Histology
Ed's Histology Notes

HYPERPARATHYROIDISM ("stone and bone disease"; review Mayo Clin. Proc. 77: 87, 2002; pathologists see Arch. Path. Lab. Med. 134: 1639, 2010)

Brown Tumor of Hyperparathyroidism
Pittsburg Illustrated Case

Brown tumor
Pittsburgh Pathology Cases

Brown tumor
WebPath Tutorial

Brown tumor
WebPath Tutorial

{10827}      parathyroid adenoma, histology

Parathyroid adenoma
Note rim of normal tissue
WebPath Photo

Parathyroid adenoma
Oxyphilic type
WebPath Photo

Nowadays, some folks talk about "just following" people with a parathyroid adenoma who doesn't have symptoms (Am. J. Med. 124: 911, 2011). I would demand surgery. If the serum parathormone level is more than three times the upper limit of normal, or there is a palpable neck mass, it's likely to be cancer and I don't think anyone would question the need to operate (Am. J. Surg. 202: 590, 2011).

Parathyroid carcinoma

WebPath Photo

Parathyroid carcinoma

WebPath Photo

{27260}      parathyroid hyperplasia (arrow sign helps)
{09271}      primary parathyroid hyperplasia, histology

Parathyroid hyperplasia

WebPath Photo

Parathyroid hyperplasia
You cannot tell this from adenoma by itself
WebPath Photo

Parathyroid hyperplasia
Note cell uniformity. Uremia.

HYPERCALCEMIA: Differential diagnosis for beginners. Review Postgrad. Med. 115: 69, 2004.


Child with pseudo-pseudo-hypoparathyroidism
Courtesy of Mary Fay MD


Thymus Exhibit
Virtual Pathology Museum
University of Connecticut

Thymus Histology
Ed's Histology Notes

{14760}      normal kid's thymus; a=cortex, b=medulla, c=vessel
{13958}      Hassall's corpuscles stained for keratin (this appears to be normal thyroid)

{13952}      thymoma, gross
{25653}      thymoma, gross
{13955}      thymic tumor, possibly Hodgkin's
{49097}      malignant thymoma, gross

Pittsburgh Pathology Cases

Non-Invasive Thymoma
Pittsburgh Illustrated Case

PINEAL ("the third eye"): Tumors of the pineal are troublesome because of their location. In children, pineal tumors are likely to produce sexual precocity.

{03998}      normal pineal gland, anatomy
{02815}      normal pineal gland, gross
{01223}      normal pineal gland
{01239}      normal pineal gland histology, with brain sand
{05219}      pineal cyst, gross
{01711}      pineal germinoma, gross

Pittsburgh Pathology Cases

* THE MELATONIN BUSINESS: Older review Am. Fam. Phys. 57(8): 1783, 1998.




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