Help With Pathology?

[XrenegadeZ]

One of my biggest problems with pathology is been able to describe a histology slide. I have tried several approaches to tackling these issues but have not succeeded in getting it right. So i am hoping that someone in this forum will point me in the right direction I.E, give a link to a site that shows this, or a book i can purchase (at a reasonable price) that will teach me how to describe histological slides. Cheers

 

On the other hand, here is a typical example... of what i cant do

 

http://www.microscopyu.com/galleries/pathology/chronicpneumonialarge.html

I have two questions based on what is shown in that link...

 

1 - Can anyone of you describe the histological slide displayed on that website?

2 - Secondly, the slide talks about causative agents, does anyone know of the causative agents associated with Chronic Pneumonia? at least 4

 

This carries too many questions, so any one answer you can conjure up will do. Dont worry about answering everything... Thanks in advance

[blazarwolf]

1.Well those cells are distintivly RBC's and it sure does look like avioli to me, though its hard to tell if that is a bronchiol over top left cuz its filled with RBC's (its been along time, forgive me). The only other thing i could think of looking like this with so many tight groupings of red blood cells is red marrow, though i dont think it would look like this at all. Oh also pneumonia is a lung issue so unless its a trick question your looking at avioli (tiny air sacs in lungs where RBC's pick up oxygen).

 

2. off the top of my head the 2 common Chronic ones are Tubercolosis and MRSA, There are many many many cuases for pneumonia, go to wikipedia for more.

 

3. At any university that has A&P go to there bookstore they may have a hystology guide with lots of good pictures, or just get into a lab. It just takes practice, Knowing what tissues look like what... Many tissues look very similar and are only visibly different by a few extra layers or structures, that one is not so, its very distintive tissue. The most repeated saying in histology is "Form follows Function"

[Callie]

The main cause of pneumonia is bacterial infection but it can also be viral. Less often pneumonia may occur as a result of inhaling something which may damage the lung tissue (smoke/chemicals)/fungal infection/allergies.

 

When you say you have problems describing histological slides - do you mean the general appearance or identifying the individual elements (cell types/tissue layers etc)?

[blike]

One of my biggest problems with pathology is been able to describe a histology slide. I have tried several approaches to tackling these issues but have not succeeded in getting it right. So i am hoping that someone in this forum will point me in the right direction I.E, give a link to a site that shows this, or a book i can purchase (at a reasonable price) that will teach me how to describe histological slides. Cheers

 

On the other hand, here is a typical example... of what i cant do

 

http://www.microscopyu.com/galleries/pathology/chronicpneumonialarge.html

I have two questions based on what is shown in that link...

 

1 - Can anyone of you describe the histological slide displayed on that website?

2 - Secondly, the slide talks about causative agents, does anyone know of the causative agents associated with Chronic Pneumonia? at least 4

 

This carries too many questions, so any one answer you can conjure up will do. Dont worry about answering everything... Thanks in advance

As to your specific questions:

 

#1 - It's hard to give a very detailed description without a more macro and micro picture. What you're seeing in that picture looks like some sort of suppurative chronic pneumonia. The alveolar walls are thickened and the alveolar space, which should normally be filled with air, is filled with neutrophils. What you see in the upper left corner of the picture is most likely an arteriole filled with RBCs, however without a closer picture I can't be certain.

 

#2 One poster above mentioned MRSA as a chronic pneumonia -- this is not correct. MRSA will almost certainly present acutely. M. tuberculosis is the classic bacterial cause of chronic pneumonia, however other bacteria such as Actinomyces israelii, and Nocardia can also cause a chronic pneumonia. Fungi can also cause chronic pneumonia -- blastomycosis and coccidiomycosis are the typical examples.

[Callie]

Ive got quite an old Pathology text book - Stevens and Lowe, which is useful for a bit of background reading.

 

My book has a similar picture to the one you have linked to titled 'Bronchopneumonia'. Underneath the pic the description states 'the inflammation is centred on bronchi spreads out to cause inflammation in the alveoli, which contain acute inflammatory infiltrate. Consolidation is in the dependant parts of the lung.' Which probably isnt much help to you! but I am a little confused as to exactly what you mean by describing pathology slides.

[blazarwolf]

Forgive me for not researching, but to my understanding MRSA is a staff infection resisitant to anti-biotics... How would this not constitute a chronic deasese? Acutley presenting can be to anything (other than prolonged enviormental exposer as someone mentioned).

[blike]

Forgive me for not researching, but to my understanding MRSA is a staff infection resisitant to anti-biotics... How would this not constitute a chronic deasese? Acutley presenting can be to anything (other than prolonged enviormental exposer as someone mentioned).

You are correct in your understanding that MRSA is resistent to some antibiotics. It's actually a misnomer that MRSA is resistant to all antibiotics, or even most antibiotics. MRSA stands for methicillin resistant Staphylococcus (short "staph") areus. Thus, any staphylococcus aureus culture which is resistant to methicillin is classified as MRSA. However, many MRSA strains are susceptible to doxycycline, clindamycin, linezolid, TMP-SMZ, and even flouroquinolones. The susceptibilities often depend on whether or not the MRSA is community acquired or hospital acquired.

 

In medicine we often use the word chronic as an adjective to describe a disease that is slow to develop. Patients who develop MRSA pneumonia will develop symptoms very quickly because MRSA is evokes such a strong immune response. It is not considered a chronic disease because the disease has a rapid onset and patients will get sick enough to present to the hospital (or their primary care physician) seeking treatment. Patients don't walk around in the community with a MRSA abscess in their lungs.

 

However, the fungal organisms I mentioned earlier often do have a slow onset of disease and a longer clinical course. Patients can walk around in the community with these pneumonias and have very minor or even absent symptoms.

[blazarwolf]

Thank you for the clarification...

 

However, the fungal organisms I mentioned earlier often do have a slow onset of disease and a longer clinical course. Patients can walk around in the community with these pneumonias and have very minor or even absent symptoms.

 

 

This scares me... Ive seen some mold grow in my house. I never expected it to be Extraordinarly dangerous, becuase there are many non-dangerous cultures, and Ive been around it alot and never felt a symptom....

 

1) What is the progression of fungul lung infections?

2) How good are modern-day Anti-fungal treatments?, major side-effects?.

 

Dont worry about it if i went outside you realm... you sound atleast an RT.

[blike]

Thank you for the clarification...

 

This scares me... Ive seen some mold grow in my house. I never expected it to be Extraordinarly dangerous, becuase there are many non-dangerous cultures, and Ive been around it alot and never felt a symptom....

 

1) What is the progression of fungul lung infections?

2) How good are modern-day Anti-fungal treatments?, major side-effects?.

 

Dont worry about it if i went outside you realm... you sound atleast an RT.

The progression of fungal pneumonia varies depending on the organism. Organisms like histoplasmosis and blastomycosis are endemic to certain regions (ohio river valley and lower mississippi river respectively), but infection with these organisms is relatively rare. Often times infections are subclinical and self-limiting. Asymptomatic non-immunocompromised patients aren't even treated usually. If the infection is systemic or the patient is experiencing symptoms, the infection is usually treated with an oral antifungal -- itraconazole and amphotericin B are typical examples. Itraconazole is tolerated pretty well, sometimes patients have a bit of diarrhea. It's also slightly hepatotoxic, so you might see a bump in the liver enzymes. Amphotericin B has a bigger side-effect profile which you can look up if you're interested. There are different formulations that try and minimize the side-effects. Generally the medications work very well. Usually the only time you see a fungus really someone a lot of trouble is in the immunocompromised (cryptococcus and aspergillis especially). For the record I'm a 4th year medical student.