Pathology of the Integumentary System - Part 5 Flashcards
Nodular/diffuse dermatitis
1. This can be both?
2. What clues can the inflammatory infiltrates provide us?
- Infectious or noninfectious
- Depending on the Inflammatory infiltrates, you can have a clue of the underlying process:
- If majority are Neutrophilic –>(e.g. bacterial)
- If majority are Eosinophilic –> (e.g. parasitic or eosinophilic
granuloma) - Histiocytic - chronic granulomatous or
pyogranulomatous lesions (e.g.
mycobacteria, fungal, foreign body)
What can be seen here?
Nodular on left, diffuse on right
What can be seen here?
Nodular
What can be seen here?
MNGC are surrounded fungal hyphae
What is can be seen on clinical presentation in cases of Nodular/diffuse dermatitis?
- Nodular or plaque-like lesions that may be alopecic, sometimes ulcerated,
or draining tracks adjacent to nodules .
What can be seen here?
Nodular/diffuse dermatitis
What diagnostics would you run if you suspect your patient has nodular/diffuse dermatitis?
Microbial culture
* Panniculitis, draining tracts or nodules:
* Tissue culture (sterile procedure) for aerobic and anaerobic bacteria,
Mycobacterium, and fungi
* Use excisional biopsy or double-punch method
Divide biopsy of skin into three different ways: Punch, incisional/wedge, excisional.
Brown part is lesion. Want to get sample from the center. For nodule you want to get the entire thing, including the margin.
Main takeaway: Use excisional and double punch method for tissue culture. Remaining tissue is used for biopsy.
Right side: Basically a double punch biopsy.
Canine leproid granuloma
1. Caused by?
2. Most commonly affects which species?
3. What part of the body is affected?
4. What can be seen grossly?
5. What can be seen histologically?
- Cause: novel mycobacterial species. (unsure of species)
- Most commonly affects short coated
large breeds such as Boxers - Pinnae
- Single to multiple well circumscribed,
firm, nonpainful dermal nodules - Pyogranulomatous dermatitis with
intralesional acid-fast positive bacteria
What can be seen here?
Canine leproid granuloma
What can be seen here?
Canine leproid granuloma
Stains typically used:
Gram stain for bacteria, acid fast for mycobacteria, and?
Special stains are not as sensitive as culture, so can not simply rule out based off of staining samples.
What can be seen here?
Canine leproid granuloma
Acid fast stain - used to identify mycobacteria
Deep and/or systemic fungal infection
1. Usually becomes?
2. Caused by?
3. Examples?
4. Clinically what do you see?
- Usually cutaneous lesions are secondary to systemic infection
(lungs, eyes, bones) - Ingestion or inhalation from contaminated soil
- Examples:
- Cryptococcus neoformans
- Histoplasma capsulatum
- Blastomyces dermatitidis
- Coccidioides immitis
Nodules, ulcers, draining tracts
What can be seen here?
Histoplasma capsulatum
What can be seen here?
Cryptococcus neoformans
What can be seen here?
Blastomyces dermatitidis
Swelling of distal limb
What can be seen here?
Coccidioides immitis
Swelling of distal limb
What can be seen here?
Histoplasma capsulatum
MQ engulf histoplasma
What can be seen here?
Cryptococcus neoformans
MQ with very thick capsule
What can be seen here?
Blastomyces dermatitidis
Specific feature: broadface budding on bottom right hand corner
What can be seen here?
Coccidioides immitis
Pythiosis
1. Is essentially?
2. Which species are affected?
3.
Water mold
* Dogs (GI signs > skin) and horses (skin signs > GI)
* Pythium insidiosum is an aquatic dimorphic water mold, Access to static water may lead to contact with pythium.
* Cutaneous form (limbs, ventral thorax
and abdomen)
* Ulcerative lesions with fistulous tracts
Pale yellow coral-like concretions
found in sinus tracts (kunkers)
* Granulomatous and eosinophilic
inflammation and granulation tissue
* Peripheral eosinophilia
What can be seen here?
Pythiosis
What can be seen here?
Pythiosis
“kunkers”
When you cut into lesions, find kunkers. Characteristic of pythiosis
Leishmaniasis
1.
2. Tranmission route?
3. Manifestation ?
4. What can be seen grossly?
5. What can seen on bloodwork?
6. Major differential?
- Leishmania sp. (L. infantum) ; obligate
intracellular protozoa - Transmission: Bite of a sandfly
- Zoonotic disease
- Cutaneous and systemic disease
- Cutaneous lesions: Alopecia, ulcers, nodules, exfoliative
dermatitis; muzzle, periorbital and aural
regions, onychogryphosis - Blood work: hyperproteinemia with
hypergammaglobulinemia and
hypoalbuminemia
6. Travel history. Organism is found only in certain parts of the world.
Leishmaniasis
Scales on skin
Leishmaniasis
Onychogryphosis: hypertrophy and increased curvature of the claws.
Leishmaniasis
cytology - Leishmaniasis
MQ engulf aamastigote o lesimaniasis
Dots in MQ –> infectious disease
Histoplasma
Habronemiasis (summer sores)
1. Also called?
2. Transmitted by?
3. Pathogensis?
4. Seen when?
5.
Summer cores
* Habronema muscae
* Nematode transmitted by flies
* Nematode passed in feces → ingested by fly
maggots → deposited onto horse by host fly
→ usually larvae are deposited in the medial
canthus of the eye and prepuce
* Usually seen in the summer and early fall
when flies are active
* Granulomatous and eosinophilic
inflammation around nematode larvae
Habronemiasis
Bottom = punch biopsy; nematode larvae
Examples of noninfectious diffuse/nodular dermatitis?
Examples:
* Sterile granulomatous dermatitis and lymphadenitis
* Eosinophilic granuloma
Sterile (non-infectious) granulomatous dermatitis and lymphadenitis
(?)
1. Also called?
2. Effects which dog breeds?
3. What age group is impacted?
4. What parts of teh body are affected?
5. Clinically what can be seen?
6. Caused by?
Juvenile cellulitis, puppy strangle - puppies get very swollen muscles, sometimes get? neck looks swollen
* Golden retriever, Dachshund, Labrador
retriever and Gordon setter predisposed
* Mostly in young dogs; also in adult dogs
* Facial swelling, papules, pustules affecting the periocular skin, muzzle and pinnae
* Fever, lethargy, hyporexia and
lameness, lymphadenomegaly
* Cause unknown. Responsive to immunosuppressive drugs (My have immuno component).
* Nodular pyogranulomatous dermatitis
Sterile granulomatous dermatitis and lymphadenitis
Manifestation of Eosinophillic granuloma complex
Eosinophilic plaque
Manifestation of Eosinophillic granuloma complex
Indolent ulcer
Manifestation of allergic disease
Manifestation of Eosinophillic granuloma complex
Arrow pointing to eosinophils
Cytology from a cat with indolent ulcer