Happy New Year's

You pull the short straw and get stuck with the New Year's Eve shift. A van pulls up to the curb of your ER and rolls a body out onto the doorstep before driving away. The patient looks like he's in his early 20s. He stumbles around looking pretty unsteady. You can't really elicit a history from him; his speech is slurred and he seems to have some memory impairment. His eyes look like this (click on image to make it move!):

With a big sigh, you run tests and rule out head trauma, hypoxia, hypothermia, hepatic encephalopathy, and other metabolic disarrangements. There is an elevated osmolal gap.

Challenge 1: What's the diagnosis? What's seen on the image?

Two days later, a different patient is brought into your ER by the police; he was seen on the streets shouting about the ninjas attacking him and vomiting. He looks to be in his mid-30s and he is very disoriented. He can only tell you about the pink elephant in the room, and any attempt to calm him just riles him up more. On exam, you find tachycardia, tachypnea, hypertension, a low grade fever, and marked diaphoresis. One of the bystanders comments that he's "seen this man before - he's always drinking and panhandling for more booze."

Challenge 2: What's the diagnosis?

Image shown under GNU Free Documentation License.

X Marks the Spot

On your last day of pediatric preceptorship, you see a 13 year old boy complaining of "weird spots" on his lower abdomen and butt. He also says that since a few years ago, he often has burning pain in his hands and feet, especially when he has a fever. This pain radiates proximally and is sometimes relieved with rest. On exam, you notice the following two findings (the second is seen by the slit-lamp):

When you ask the patient about his family history, he tells you that his uncle on his mother's side recently received a kidney transplant. This uncle also has skin lesions and extremity pain.

Challenge: What is your diagnosis?

Related Questions:
1. What is the skin finding?
2. What is the eye finding?

This case written by Kate Dinh.
Both images shown under fair use.

It's Not...

This woman storms into your office, absolutely outraged (or, by the blush on her cheeks, embarrassed?). She shouts, "The other doctor accused me of having syphilis! He said a lab test even confirmed it. I can't possibly have syphilis. I haven't slept with anyone in years."

Challenge: Explain.

Case idea contributed by Alex Penn.
Image is in the public domain.

Merry Christmas

A 14 year old boy presents to your clinic with a swollen and painful left knee. He said it was preceded by stiffness and followed by a warm sensation, then acute pain. There is no history of trauma; the boy just played a basketball game. You send off labs and get a normal platelet count and PT, and a prolonged aPTT. A mixing test corrects the abnormality. You send off a specific factor VIII assay; it's normal.

Challenge: What's the next most likely diagnosis? This disease has another name; who was it named after? What is its transmission?

Related Questions:
1. What's the differential for a normal PT and a prolonged aPTT?
2. (Review) A normal aPTT and a prolonged PT?
3. (Review) A prolonged PT and aPTT?

The Answer is Stroke

A forty year old woman presents with a stroke, but doesn't have the traditional risk factors (smoking, hypertension, or hypercholesterolemia). Instead, she presents with a swollen tender right calf after an 18 hour plane ride. She is currently on oral contraceptives. When you look at her hands, you notice cyanosis and the following finding:

Challenge: What's the cause of the stroke? What's the status of her lungs? What's the physiology of her heart?

Related Questions:
1. What is shown on the image?

This case idea contributed by Alex Penn.
Image is in the public domain.

Trompe-l'oeil

An 18 year old girl comes into your primary care clinic for an annual physical for her to play water polo. At first glance, she appears to be normal and healthy. However, on exam, you find a pulse of 50, BP 95/55, and QT elongation on EKG. She stopped menstruating over a year ago, but she says that it's probably due to her sports; she is unconcerned. When you ask her about school, she says her grades are all A's, but she doesn't seem to have much self confidence. As she talks, you notice chapped lips. On exam, you find this on her arms.

Challenge: This constellation of symptoms and signs worries you that she may have or be at risk for what disorder?

Related Questions:
1. What is seen on the image?

Image shown under fair use.

Scar

An ambulance brings an unconscious woman into your ER, but no one is able to tell you what happened to her. A quick exam shows heart rate 110 bpm, respiratory rate 24, blood pressure 100/60, and temperature 102 F. She appears to be in her thirties and looks very sick. There is a well-healed abdominal scar on the left upper quadrant.

Here's what a blood smear might show (arrow indicates abnormal finding):

Challenge: You suspect an infection. What type of organisms are most likely?

Related Questions:
1. What does the blood smear show?
2. What is the relevance of the scar?

Image shown under fair use.

Terrible T's

A 45 year old woman presents complaining of weakness that comes and goes. It's worse in the evening and after she plays tennis. She also complains that her tennis game is being affected because sometimes things "look funny." You suspect she's seeing double. On exam, you notice ptosis.

CXRs are shown above. You recognize the abnormality and remember the differential with the "T mnemonic."

Challenge: What's your diagnosis?

Related Questions:
1. What's the finding on the CXRs?
2. What's the T mnemonic? (or what is the differential for the abnormality?)
3. How does that relate to the patient's presentation?

Image shown under fair use.

Nerd Sniping

Someone compared this experiment to this comic from xkcd:
I was amused. Anyway, I'm happy with the way these cases are right now. I have a ton of ideas, but researching them, finding images, and writing up the cases and solutions takes time. Before the end of the year, I'll try to run some more really fun ones. Starting next year, I'll focus on more bread-and-butter USMLE 1 cases. I don't know how much longer things will last, but I'm having fun and hope you are too.

Image from xkcd.com, licensed under Creative Commons.

All That and a Bag of Chips

A 60 year old smoker presents with right shoulder pain that radiates up his neck and down the ipsilateral arm. He complains of dyspnea, non-productive cough, and facial swelling (worse when he bends forward or lies down). Here's another picture:

Here is a CXR of a similar patient (not the same because the finding is on a opposite side).

Challenge: This case has so many random syndromes, it seems almost artificial; it'd be such a good teaching case, you think. What's the final diagnosis? (Be specific - it's named after a Quaker who was, according to Wikipedia, the first professor of radiology).

Related Questions:
1. What's seen on the first image?
2. What's seen on the second image?
3. What's seen on the CXR?
4. Why the shoulder pain?

Images are all shown under fair use.

Also the Name of a Motorcycle

An Asian family brings their 2 year old boy into the emergency department complaining of irritability and a week long fever. They say he doesn't like to play outside anymore. On exam, you note a conjunctivitis in both eyes without exudate. His lips are chapped and erythematous. There are no ulcers or vesicles. You notice a rash on his perineum, trunk, and extremities.

Challenge: This child is at risk for serious complications. What imaging modality do you need to send him for?

Related Questions:
1. What's seen on the image?
2. This is a classic presentation of what disease?

Image shown under fair use.

History Lesson

It is 1985. An 18 year old woman presents to your office with a diagnosis of adenocarcinoma of the vagina. There is no family history of any cancers.

Challenge: Tell me about her mother.

Vera

A 60 year old man presents with an unusual chief complaint: he gets really itchy after he takes a bath. As you inquire further, you find other nonspecific complaints such as headache, weakness, dizziness, and excessive sweating. He also gets a weird sensation of burning pain in his hands and feet that's accompanied by erythema or cyanosis but he says that he feels a pulse when it happens. Past medical history is positive for peptic ulcer disease. On exam, you palpate a spleen and liver. You get back a CBC and well, all the numbers seem high. Here's a bone marrow biopsy stained for iron, 400x:


Challenge: What's the diagnosis?

Related Questions:
1. What's the symptom of itchiness called?
2. What's the symptom of burning pain called?
3. What's seen on the histology image?

Image shown under fair use.

It's Raining...

A 35 year old male presents with diarrhea and abdominal pain. This is seen on endoscopy. The patient does not take NSAIDs and is negative for H. pylori. When you take a further history, you find that the patient had a parathyroid tumor at age 30 which was successfully treated. His mother had some "pituitary thing."

Challenge: What's the cause of the finding seen on endoscopy? The patient also has an familial endocrine disease; what is it?

Related Questions:
1. What's the endoscopy finding?
2. The second part of the challenge involves "3P's." What are they?

Image shown under GNU Free Documentation License.

All In

A 66 year old African American male presents with pain in his back and chest. The pain gets worse with movement and does not occur at night except when he changes position in bed. The patient also said that he used to be 6 feet, but now he's only 5'10". He also complains of weakness, tiredness, and some weight loss. You are unsure what is going on so you order some basic lab tests, including a peripheral blood smear (shown above). The abnormality is indicated by the arrow. Luckily, you remember seeing this in your hematology block.

Challenge: What's the clinical diagnosis?

Related Questions:
1. What's the finding on the peripheral blood smear called?

Image shown under fair use.

Mouth

A 50 year old homeless man presents to the ER with slurred speech, nystagmus, and unsteady gait. There is no history of head trauma. His blood smear is above with the abnormal cell marked by the arrow. This is not a hereditary or genetic condition.

Challenge: What is the cause of this finding?

Related Questions:
1. What is the blood smear finding called?

Image shown under fair use.

Gunner

Here's an easy one. As a gunner, you begin studying for Step 1 of the Boards in the fifth grade. A 65 year old male has a BNP of 500 pg/mL and a CXR that looks like this:

Challenge: What are some treatments for this?

Related Questions:
1. What does BNP measure?
2. What do you see on the CXR?
3. What is your diagnosis?

Image shown under fair use.

Happy Thanksgiving

A 30 year old man returns from a trip to Turkey where he visited some relatives on a farm. He presented to his local hospital a few days ago with a pneumonia: fever, cough, shortness of breath, headache, myalgia, and sore throat. The respiratory distress got worse and was soon accompanied by diarrhea. The referring hospital could not identify the etiology of the pneumonia; all the usual suspects were tested and negative. Radiographic findings show diffuse bilateral ground-glass infiltrates, which signifies very poor prognosis.

Infections by this bug have also been documented in Thailand, Vietnam, Indonesia, Cambodia, China, Azerbaijan, Laos, Djibouti, Egypt, Nigeria, and Iraq.

Challenge: This is an unfortunately nonspecific presentation, but give a guess for the causative organism.

Cat's Cradle

You are a third year rushing through the hospital to get coffee for your intern (and thus hopefully an "honors"). As you pass the pediatric ward, you hear a cat meow. "That's weird," you think, "why would someone bring a pet cat into the hospital?"

Suddenly, you hear the voice of your intern. "Yes, the chart indicates she was five pounds when she was born, and she hasn't been growing normally since. We'll have to monitor her cognitive, speech, motor, and behavioral progress as they may be delayed. Let me measure her head. Hmm, it's a little small."

The mother asks, "But what is wrong with her?"

The intern says, "I believe she has a syndrome called..." At that moment, he glances out the room and sees you. "Oh, this is the medical student on the team." You awkwardly introduce yourself. Well, you didn't get coffee and you were caught eavesdropping; you better impress your intern by knowing the diagnosis.

Challenge: What chromosome in this baby would be abnormal?

Related Questions:
1. What would a small head be called?
2. What is this syndrome called?

Note: The answer to this case might be posted a little later than usual. But it's a hard one - good luck.

Cool

This is the rare non-case post. We had our cancer midterm today, and one of the problems mirrored exactly one of the cases here. How exciting! Also, there will be a new case tomorrow, but I'm not sure if there will be a case Friday owing to the Thanksgiving holiday. (Perhaps I will desperately try to find a turkey-related disease).

Pathognomonic

Challenge: What is the causative organism?

Related Questions:
1. What is seen on the CXR?

Image is in the public domain.

Pandora's Box

The finding in this barium enema is seen in a young female. She also has the finding seen in the image below:
These characteristic spots are flat and brown. "I've always had freckles," she says, but you notice these spots are on her lips, around her mouth, and on the buccal mucosa. She also has some on her hands and feet.

If you were to do a colonoscopy, you'd find many polyps with variable size and features. Unfortunately, this is an inherited condition and it predisposes the patient to many different cancers of the GI tract, pancreas, liver, lungs, breast, and ovaries.

Challenge: What's this syndrome called?

Related Questions:
1. What is seen on the barium enema film?

Both images shown under fair use.

Anatomy Basics

This patient has trouble raising her arms above her head. She is currently pushing her arms against the wall. Note the appearance of the scapula.

Challenge: The most common cause is weakness in which muscle group? What is the innervation of that muscle group?

Related Questions
1. What is this presentation called?
2. Which muscles stabilize the scapula to the torso?

This case idea contributed by Kate Dinh.
Image shown under fair use.

PedsHemOnc

In your pediatric preceptorship, you meet a 7 year old boy who presents with fatigue and pallor. When you plot his growth on a chart, you find that he is short for his age, but he has always been this way. When you take a thorough history, you find that he has seen a doctor in the past for recurrent bacterial infections and an episode of hemorrhage. Both his parents are healthy and have no major medical conditions. However, the father said some of his relatives had been diagnosed with acute myelocytic leukemia. The mother said that some of her relatives had been diagnosed with squamous cell carcinoma of the head and neck. On exam, you notice several cafe au lait spots, "funny thumbs," and hypogonadism. Blood smear shows macrocytosis.

Challenge: What is your diagnosis?

Related Questions:
1. A deficiency in which blood cell type would lead to fatigue and pallor?
2. A deficiency in which blood cell type would lead to recurrent bacterial infections?
3. A deficiency in which blood cell type would lead to hemorrhage?
4. What is the combination of the above three findings called?

Shocking

It's a balmy June afternoon when a young man is rushed into the ER with superficial but not deep burns. You see this on his back. This feathering skin injury is pathognomonic for this case, but will fade within hours. You immediately stick EKG leads on this patient as he is at risk for cardiac arrhythmias. He mumbles that he was "just playing football when it happened."

Challenge: When what happened?

Related Questions:
1. What's the finding in the image?

(I have to say I'm particularly proud of discovering this one. I think it's really cool.)

Image shown under fair use.

Heart of the Matter

Challenge: Diagnosis?

Related Questions:
1. The red box in the second image marks an interval. What interval is it and how long is it?
2. What does the blue box represent?
3. The blue box plus the green box represents something. What interval is it and how long is it?

Both images are shown under GNU Free Documentation License.

Dancing

This case idea was taken from a talk by Dr. Yvonne Wu for the pediatrics subspecialties elective.

You see a 20 month old toddler, brought in because of stumbling. The child was able to walk fine several days ago, but now looks uncoordinated with rhythmic jerking of the limbs. When you examine the child, you notice his eyes have rapid, dancing movements. They are spontaneous, arrhythmic conjugate saccades in all directions.

Challenge: Unfortunately, this is a paraneoplastic syndrome associated with a tumor. What tumor are you worried about?

I Spy

Despite being an avid follower of Case of the Day, you get miffed at the silly cases so far. "Craig, what's up with all your cases? Sure, some of us might consider dermatology or radiology, but you know like 50% of us are heading for ophtho. You need to have an ophtho challenge!"

Well, never fear.


You appreciate this on ophthalmic exam. There are several things that can cause this appearance, but one of them is particularly likely in this patient of Ashkenazi Jewish descent.

Challenge: This person has an accumulation of something in his cells. What is it?

Related Questions:
1. What is the finding here called?
2. There could be a vascular cause of this finding. Which artery would be involved then?

Image is in the public domain.

Arr!

Happy Halloween!

Captain Jack Sparrow arrrrives at your arrmergency deparrrrtment, needing arrrgent care. You spy some missing teeth when he cries, "Bring me a noggin of rum, now won't you matey?" He looks pretty pale and you notice his gums be bleedin'. When ye eyeball his tongue, you be seeing somethin' like this:


Now, this lubber ain't the pirate in your clinic, but the tongue looks about the same.

Challenge: What be your treatment for this here condition?

Image is in the public domain.

How Now Brown Cow

A 55-year-old immigrant from France without known history of IV drug use or structural heart disease presents with the signs and symptoms of infective endocarditis. You isolate an unusual organism, a Gram positive coccus susceptible to penicillin that is non-hemolytic on blood agar. It grows in 40% bile but not 6.5% NaCl and hydrolyzes esculin but not arginine.

Your attending tells you to do a colonoscopy.

Challenge: What is the organism? Why the colonoscopy?

Poison

Since the last three were poisons, I wanted to finish this week with a last poison case. Originally, I was going to do radiation poisoning, but the symptoms are too nonspecific. So onto this case, which is an important one to know since it's common...

A college student brings his roommate into the ER. The roommate is confused and disoriented. This is what he looks like:


The patient is sweaty and pale. The roommate says he's been vomiting and lethargic all day. You get some labs and they indicate AST 5000 IU/L and ALT 6000 IU/L. PT is elevated. The roommate says the patient was well a couple days ago.

Challenge: What is the pharmacologic treatment?

Related Questions:
1. What does the image show?
2. What's the diagnosis? What is the biochemical pathophysiology?

Image is in the public domain.

Jeopardy

Alex Trebek: This compound is highly toxic with an LD50 of about 10mg. It's featured in lots of books and movies as an extremely bitter colorless compound found in nature. Its mechanism of action is to act on a ligand-gated chloride channel. Thus, you might expect that soon after exposure, the muscles in the head and neck begin to contract involuntarily. Soon, the patient will look like this painting below (which depicts a similar disease). Death occurs in hours from asphyxiation, and there is no antidote.


Challenge: What is...? (the compound shown above)

First image shown under GNU Free Documentation License.
Second image is in the public domain. It is a painting by Sir Charles Bell of a disease with a similar clinical picture.

Case of the Week

This week happens to be a national awareness week for this case. Good luck!

A mother brings her 5 year old child into your clinic this morning, saying that her daughter has been vomiting the entire night. When you look at the child, she appears obtunded and lethargic; she is fairly nonresponsive to stimuli and when she walks, she stumbles about.


Here is her blood smear (Wright's stain) with the abnormal findings indicated by the arrows.

Challenge: If you know that this is not congenital, then the differential narrows down to...what?

Related Questions:
1. What's seen on the blood smear?
2. What's the clinical diagnosis?

Image shown under fair use.

Amabilis

You have just graduated from the Austrian Academy of yodeling, waltz, and pathology. Congratulations! Your first assignment, however, is a grim one. The person shown in the image above passed away due to mysterious causes. Foul play is suspected. You find out a new chef was hired recently, but the guards said that they search everyone for poisons and the chef was clean.

Upon further investigation, you find out that the victim had a special meal prepared for him over a week ago. After a few hours, he felt really sick with a severe right upper abdominal pain, diarrhea, and vomiting. The doctors assure you that they made sure he didn't have any electrolyte or fluid imbalances.

Curiously, these symptoms resolved a few days later, but were replaced by more worrisome ones. He woke up with yellow skin and conjunctiva, exhibited signs of delirium, and even had a seizure. He then went into a coma. He passed away eight days after eating the dinner. Doctors think that he may have had renal failure.

Challenge: It was the chef in the kitchen with the...what?

Related Questions:
1. Why was the mode of death not detected by the guards?
(2. Who is the person shown in the image above?)

Image is in the public domain.

Shiga

A five year old baby is brought in five days after a severe episode of bloody diarrhea. The labs do not look good. Creatinine is elevated, platelets are low, and the baby is anemic. When you look at the RBC's, you see the image above. On exam, you find no neurologic abnormalities.

Challenge: What is the most likely diagnosis?

Related Questions:
1. What are low platelets called?
2. What is seen on the image?

Image shown under fair use.

Proteus

You decide to do some international work in India and at one of the clinics, you see this man. He is about 40. He says that he has had this for a while. The tissue is hard to the touch. He says that he came in today because his urine was milky white. Blood tests show eosinophilia.

Challenge: What is the diagnosis? What is the causative agent?

Image is in the public domain.

Zoo Noses

A 25 year old female spelunker presents to your clinic. Since you are thirsty, you pull out a bottle of water, and as you do so, she gasps in panic and looks terrified.

Challenge: What's the diagnosis?

It'd be impressive if you could figure it out from just that, but you take a more thorough history. The patient says that she's really thirsty but can't look at water. She's been having trouble swallowing. She's salivating and febrile. She thinks she had the flu last week: muscle weakness, loss of appetite, sore throat, headache, low grade fever, and nausea. You request a psychiatric consult which suggests recent hypomanic episodes.

It's a pretty cool case, but she'll die if you can't figure this out. You admit her to your service.

Related Questions:
1. What's up with spelunking?

Scalars and Vectors

In between first and second year, you "volunteer" down in South America, scaling mountains, trekking through rainforests, tanning on beaches, and mingling with the locals. You spend your spare time volunteering in a clinic. One day, this child walks in:

Your language skills aren't too good, but you gather that something might have bit him. A bug or fly maybe? You figure this might be important information, so you have the child draw what he saw. This is what he draws:


Hmm...not bad. You examine the boy more closely. The pertinent finding is his right eye, where he says the bug bit him. He has no other symptoms, but you're a little worried. You draw some blood and see this with a special stain:


Challenge: If left untreated, this patient may develop a cardiac manifestation of the disease. What would that be?

Related Questions:
1. What is the finding in the first image?
2. What is the bug in the second image?
3. What is seen in the third image?
4. What is the diagnosis?

All images are in the public domain.

Basic Immunology

This case idea is contributed by Alex Penn. It is really cool.

As an immunology expert, you are consulted on a two day old boy with a known mutation in the common gamma chain cytokine receptor polypeptide. The boy has been kept in sterile isolation in the hospital after a normal uncomplicated vaginal birth. He presents with weeping and scaling erythroderma. The neonatalogist notes that he has malabsorption and hypoalbuminemia. The team rules out any infectious cause because of the sterile isolation.

Challenge: What is going on here?

Related Questions:
1. What is the significance of the mutation?
2. Why is this more likely to happen in boys rather than girls?

Paint by Numbers

Concerned parents bring in their toddler who has the presentation seen above. This rash extends to the bridge of the nose and a bit around the mouth, but is mostly on the cheeks. When you examine the baby, you find a red rash on the arms and legs. The rash has been there a week, and it gets worse with sun exposure. The child may have had a fever around that time. There have been no new environmental exposures, foods, or pets. You rule out child abuse.

Challenge: What is the disease? What is the cause?

Image shown under GNU Free Documentation License.

Heart

*This case is related to Monday's case (scroll down).

You and your attending see the man you met on the MUNI (in the previous case). The attending says that he would like to start the patient on the following regimen of three drugs:
After starting these drugs, the patient steadily improves. Two months later though, he returns to SFGH with eye complaints. He says that he has blurred vision and sees floaters. Sometimes, he gets the sensation of flashing lights. You measure his visual acuity and it's gotten worse. On fundoscopic exam, you see an intense inflammatory reaction. Your attending says that the patient's symptoms stem from an infection of one of the eight human herpesviruses.

Challenge: Which herpesvirus is causing these eye problems? What is the relationship between the therapy and these eye problems?

Related Questions:
1. What are the drugs shown? What is the regimen called? Hint: that second drug is an analog of cytidine.

Images are shown under GNU Free Documentation License or are in the public domain.

Muni*

You are a fresh third year ready to begin your internal medicine clerkship at San Francisco General Hospital. As you get on the MUNI to get to SFGH, you see a guy sitting across from you with these lesions on his legs and nose:

When you and that man get off at the bus stop, he turns to you and says, "Ah, you must be a student doctor. What do you think I got?"

Challenge: What's the cause of the skin lesion? What else does this person have?

Related Questions:
1. What is the skin lesion called?

Image is in the public domain.

*This will be a two part case! The next part will be released on Wednesday.

Mom Wants Antibiotics

A mother brings her 14 year old boy into the clinic because he's been complaining of a fever, sore throat, and headache. He also has pain when chewing; he hasn't been eating much. He says it hurts when he drinks apple juice or orange juice. On exam, you see this at his right neck:


As a well-trained medical student, you ask the mother to step outside while you ask the boy about sex, drugs, and rock-and-roll. He whispers, "Well, there is this one thing...my balls really hurt." You see that he has a swollen left testicle and swollen inguinal lymph nodes on the left side.

Challenge: What is the causative agent of this disease?

Related Questions:
1. What is seen in the image?
2. What is the testicular finding called?

Image shown under fair use.

Something You Won't See

These skin lesions were preceded by symptoms of abrupt high fever, aching, and vomiting. The lesions started at the mouth and face, then moved to the arms, hands, and rest of the body over a week. The palms and soles are affected, and the lesions are all about the same size. In the most common type of this disease, these skin lesions will fill up with pus and either remain discrete or merge together into sheets.

Challenge: Why is this disease notable?

Image is in the public domain.

Darling

You are doing an away fourth year rotation in Cincinnati. Why? You're not sure either. You meet a chicken farmer who is HIV positive with the finding seen above. Here's a silver stain:


Challenge: Certainly, many things could be on the differential. But what's your top suspicion?

Related Questions:
1. What's seen in the first image?
2. What's seen in the second image?

Both images are in the public domain.

Mad Scientist

You are playing around with a slide. While heating it, you pipet a bit of phenol plus this:


You then wash it a bit with water and acid alcohol before adding:


This is what you see:

This picture is a clinical correlation:


Nothing can be cultured out.

Challenge: What is the diagnosis?

Related Questions:
1. What's the stain used?
2. What is the significance of nothing being cultured out?

All images are in the public domain.