Pathology of the Integumentary System - Part 5 Flashcards
(96 cards)
1
Q
Nodular/diffuse dermatitis
1. This can be both?
2. What clues can the inflammatory infiltrates provide us?
A
- 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)
2
Q
What can be seen here?
A
Nodular on left, diffuse on right
3
Q
What can be seen here?
A
Nodular
4
Q
What can be seen here?
A
MNGC are surrounded fungal hyphae
5
Q
What is can be seen on clinical presentation in cases of Nodular/diffuse dermatitis?
A
- Nodular or plaque-like lesions that may be alopecic, sometimes ulcerated,
or draining tracks adjacent to nodules .
6
Q
What can be seen here?
A
Nodular/diffuse dermatitis
7
Q
What diagnostics would you run if you suspect your patient has nodular/diffuse dermatitis?
A
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
8
Q
A
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.
9
Q
A
Right side: Basically a double punch biopsy.
10
Q
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?
A
- 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
11
Q
What can be seen here?
A
Canine leproid granuloma
12
Q
What can be seen here?
A
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.
13
Q
What can be seen here?
A
Canine leproid granuloma
Acid fast stain - used to identify mycobacteria
14
Q
Deep and/or systemic fungal infection
1. Usually becomes?
2. Caused by?
3. Examples?
4. Clinically what do you see?
A
- 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
15
Q
What can be seen here?
A
Histoplasma capsulatum
16
Q
What can be seen here?
A
Cryptococcus neoformans
17
Q
What can be seen here?
A
Blastomyces dermatitidis
Swelling of distal limb
18
Q
What can be seen here?
A
Coccidioides immitis
Swelling of distal limb
19
Q
What can be seen here?
A
Histoplasma capsulatum
MQ engulf histoplasma
20
Q
What can be seen here?
A
Cryptococcus neoformans
MQ with very thick capsule
21
Q
What can be seen here?
A
Blastomyces dermatitidis
Specific feature: broadface budding on bottom right hand corner
22
Q
What can be seen here?
A
Coccidioides immitis
23
Q
Pythiosis
1. Is essentially?
2. Which species are affected?
3.
A
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
24
Q
What can be seen here?
A
Pythiosis
25
What can be seen here?
Pythiosis
"kunkers"
When you cut into lesions, find kunkers. Characteristic of pythiosis
26
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.
27
Leishmaniasis
Scales on skin
28
Leishmaniasis
Onychogryphosis: hypertrophy and increased curvature of the claws.
29
Leishmaniasis
30
cytology - Leishmaniasis
MQ engulf aamastigote o lesimaniasis
Dots in MQ --> infectious disease
Histoplasma
31
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
32
Habronemiasis
Bottom = punch biopsy; nematode larvae
33
Examples of noninfectious diffuse/nodular dermatitis?
Examples:
* Sterile granulomatous dermatitis and lymphadenitis
* Eosinophilic granuloma
34
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
35
Sterile granulomatous dermatitis and lymphadenitis
36
Manifestation of Eosinophillic granuloma complex
Eosinophilic plaque
37
Manifestation of Eosinophillic granuloma complex
Indolent ulcer
Manifestation of allergic disease
38
Manifestation of Eosinophillic granuloma complex
Arrow pointing to eosinophils
Cytology from a cat with indolent ulcer
39
Manifestation of Eosinophilic granuloma
Sometimes linear, plaque, papules
40
Manifestation Eosinophillic granuloma complex
Nodular
Should culture!!
41
Eosinophillic granuloma complex
42
Self-assessment - nodular/diffuse dermatitis
* What are disease examples of infectious and
noninfectious causes?
* Is infectious or noninfectious disease more
common? What additional diagnostics you
should consider?
* What are the clinical and histologic features?
* How does the character of the infiltrate give
clues to cause?
19
43
Panniculitis
1. Characterized by?
2. Caused by?
* Inflammation of the subcutis
* Cause
* Trauma
* Post injection (e.g. Rabies vaccine)
* Post surgery
* Foreign body
* Infectious disease (must rule-out)
* Pancreatic disease
* Vitamin E deficiency
* Immune-mediated
* Idiopathic
* More common in dogs
* Sterile nodular panniculitis
44
Panniculitis
in between fat lobules
45
Panniculitis
46
Panniculitis
Grossly can see nodules and draining tracts. Submit for biopsy
47
What diagnostics would you run if you suspect your patient has paniculitis?
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
48
Sterile nodular panniculitis (?)
1. Effects which species?
2. What part of the body is affected?
3. Clinically what can be seen?
4. How can you diagnose this disease?
5.
(Sterile pyogranulomatous dermatitis and panniculitis; Sterile granuloma/pyogranuloma syndrome )
Dachshunds
* Trunk
* Dermal or subcutaneous nodules, with drainage or
ulcers
* May have fever, anorexia
* May have concurrent diseases
* Diagnosis
* Rule out infectious disease: Negative tissue culture
and special stains for bacteria, fungi and mycobacterium
* Idiopathic; most cases responded to
immunomodulatory or immunosuppressive
medications
* Pyogranulomatous dermatitis and panniculiti
49
Sterile nodular panniculitis
50
Sterile nodular panniculitis (SNP)
Neutrophils surrounding
clear space used to be fat
51
Self-assessment – Panniculitis
* What’s the definition of panniculitis?
* What are the causes for panniculitis?
* What diagnostics do you want to
pursue?
52
Atrophic dermatoses (?)
1. Also called?
2. Features of this disease?
3. Caused by?
noninflammatory alopecia
* Features:
* Follicular atrophy (telogen) with follicular
keratosis
* Sebaceous atrophy
* Epidermal +/- dermal atrophy
* Cause:
* Endocrine dermatopathy
* Ischemia
* Feline acquired skin fragility
53
54
Atrophic dermatoses (noninflammatory alopecia)
Hitologically no inflammation
Diffuse telogen present which is characteristic of this.
55
Endocrine dermatoses
1. Characterized by?
2. Clinically what can you see?
4. How can you diagnose this disease?
* Bilateral symmetrical alopecia
* Hypergimentation, epidermal (and
dermal) thinning, rough, dry and dull coat
* Minimal inflammation (may see scaling
+/-secondary infection)
* The clinical, gross and histologic lesions
of endocrine dermatoses are rarely
specific
* Diagnosis based on clinical and histologic features + clinical testing for hormonal deficiency/excess (rule in/out)!
56
Endocrine dermatoses
57
Conditions in endocrine dermatoses
* Hypothyroidism --> test for T4
* Hyperadrenocorticism --> ACTH stim test
* Hyperestrogenism
* Hyposomatotropism (dwarfism)
* Hypersomatotropism
* Alopecia X
58
Hypothyroidism
1. Caused by ?
2. Affects what species? What age range?
3. Characterized by?
* Primary thyroid dysfunction caused
by lymphocytic thyroiditis or
idiopathic thyroid atrophy.
* Middle-aged dogs
* Bilateral symmetrical alopecia,
thickened and droopy facial skin
from myxedema, alopecia of the
entire tail (rat tail) [tragic facial expression]
59
Hypothyroidism
60
Hyperadrenocorticism (HAC)
1. Caused by?
2. Grossly you see?
* Cause:
* Pituitary-dependent HAC
(tumor)
* Adrenal-dependent HAC
(tumor)
* Iatrogenic (long term
treatment with steroid)
* Bilaterally symmetrical
alopecia of the trunk
* Pendulous abdomen (characteristic of cushing's disease)
* Hyperpigmentation
* Telangiectasia (veins; feature you see with cushings)
* Comedones
* Calcinosis cutis (plaques on dorsum)
Black heads?
61
Hyperadrenocorticism (HAC)
* Bilaterally symmetrical
alopecia of the trunk
* Pendulous abdomen (characteristic of cushing's disease)
* Hyperpigmentation
* Telangiectasia (veins; feature you see with cushings)
* Comedones
* Calcinosis cutis (plaques on dorsum)
Black heads?
62
Alopecia X
1. Disease affecting which species?
2. Characterized by?
3. Type of ?
4. What parts of the body are impacted?
* Plush-coated breeds
(Pomeranians, Chow Chow,
Husky)
* Bilateral symmetrical alopecia,
hyperpigmentation
Endocrinopathy - not entirely known what.
* Trunk, caudal thighs, neck,
perineal area, tail, spares head
and distal extremities
Castration is helpful but ?
63
Alopecia X
64
Hyperestrogenism
1. Caused by?
2. Chaterized by?
* Cause
* Spontaneous: testicular sustentacular
cell (Sertoli cell) tumor or ovarian cyst or
ovarian neoplasia
* Exogenous: transdermal estradiol gel
* Bilaterally symmetrical alopecia,
hyperpigmentation
* Gynecomastia (enlarged nipples) or vulvar enlargement in females
65
Hyperestrogenism
66
Self-assessment – Atrophic dermatoses
(noninflammatory alopecia)
* What are the clinical and histologic
features?
* What are the causes?
* What are examples of endocrine
diseases that causes noninflammatory
alopecia
67
Cutaneous vasculitis
1. Characterized by?
2. Caused by?
3.
* Inflammation targeting the walls of
venules or arterioles
* Cause:
* Bacterial disease
* Example: Ehrlichiosis, Rocky Mountain spotted
fever
* Bacterial septicemia
* Example: Erysipelothrix rhusiopathiae
* Immune-mediated disease
* Drug-associated
68
69
Cutaneous vasculitis
* Hemorrhage on left, Edema, erythematous macules, petechiae, ecchymoses
70
Cutaneous vasculitis
* Ulceration of distal extremities (pinnae, toes, and tail tip) with or
without sloughing of tissue
71
Swine erysipelas (Diamond skin disease)
1. Caused by?
2. What forms exist?
3. What species are affected? Age range?
4. Characterized by?
* Cause: Erysipelothrix rhusiopathiae
* Acute (septicemic/usually
fatal/cutaneous lesions), subacute and
chronic forms
* Affect growing and adult swine
* Septicemia → bacterial embolization to
the skin → vasculitis → thrombosis,
ischemia and infarction
* Multifocal, red to purple rhomboidal
(diamond) slightly raised skin lesions
72
Swine erysipelas (Diamond skin disease)
73
74
What diagnostics would you run if you suspected your patient had a tumor?
Cytology for masses
FNA for cytology
75
FNA for cytology
Clusters of epithelial cells = epithelial origin
Cells that are ? =
Individualized cells that do not cluster = round cells
76
Seen especially seen in older dogs.
Cutaneous tag = proliferation of normal skin
Follicular cyst = part of cyst accumulates keratin; gooey keratin material comes out when poked
77
Papillomavirla disese of dogs
78
79
Papillomavirus in cattle
80
Papillomavirus in cattle
cauliflower like growths
81
Epithelial - Squamous cell carcinoma
* One of the most common
malignant skin neoplasms in cats
* Cause: UV light, papillomavirus
* Lightly pigmented skin
82
light pigmented part is what is affected.
83
Mesenchymal - Equine sarcoid
* Most common skin neoplasm of
equids (horses, donkeys, mules,
and zebras), up to 90% of horse
skin tumors
* Cause: BPV-1, 2, and 13
* Locally aggressive, nonmetastatic
fibroblastic skin tumors
* Nodule, plaque, verrucous mass
* Head, periocular, ears, limbs,
prepuce
* Frequently develops in areas of
previous trauma
* Often recurs after surgical excision
84
Mesenchymal - Equine sarcoid
Lesions often a recurring problem
85
Mesenchymal – Injection site-associated
sarcoma
Mostly seen in cats post vaccination. Vaccinate in an area where lesion can be easily excised.
* Cause: Vaccines, injection of
foreign material, trauma, and
microchip implantation
* Locally aggressive with a high
rate of local recurrence; poor
prognosis
* Majority are fibrosarcomas, but
also include osteosarcoma,
chondrosarcoma,
rhabdomyosarcoma, lymphoma
86
Mesenchymal – Injection site-associated
sarcoma
87
88
Round cell neoplasia
* L: Lymphoma
* Y: Transmissible venereal tumor
* M: Mast cell tumor
* P: Plasma cell tumor
* H: Histiocytoma
Perform a fine-needle aspirate (FNA) and do a cytologic exam!
50
89
Round cell - Histiocytoma
* Neoplasia of Langerhans cells
* Dome-shaped
* Most common in young dogs
* Undergoes spontaneous immune-
mediated regression
90
Round cell - Histiocytoma
Slide on bottom = histocytes
91
Round cell - Mast cell tumor
* The most common skin tumor in dogs
(~20% of the skin tumor)
* Alopecic, solitary to multiple,
erythematous and edematous nodules
* Trunk, extremities, head
* Prognosis depends on histologic grades so always submit for biopsy
92
93
Canine cutaneous epitheliotropic lymphoma
* Older dogs
* Generalized scaling, ulcers,
nodules. Depigmentation of
lips, nasal planum
* Metastases to lymph nodes
→ systemic spread
* Poor prognosis (usually several months)
94
Canine cutaneous epitheliotropic lymphoma
95
Canine cutaneous epitheliotropic lymphoma
* Neoplastic lymphocytes are T-cells (CD3+)
96
round cells infiltrate into the epidermis which is why it is called epitheiliotrophic lymphoma
