Nodular Diseases Flashcards
1
Q
What causes a nodule or draining lesion?**
A
- Infectious
- Neoplastic
- STerile
2
Q
What are skin nodules?
A
- Circumscribed solid elevations
3
Q
Where can nodules be located?
A
- Epidermis
- Dermis
- SC tissue
4
Q
What does it mean to be adnexal?
A
- Attached to a hair follicle
5
Q
When to worry based on history about a nodule?
A
- When did you first notice the lesion?
- Any changes?
- Rate of growth (remember your signalment too!)
6
Q
Physical findings that might suggest a nodule isn’t benign
A
- Poor margins
- Depth of lesion
- Systemic signs
- Manipulation alters the lesion
- Location on the body
7
Q
Things to observe about a nodule:
A
- Location on body
- Location within the skin
- Alopecic or haired
- Is the surface ulcerated?
- What are the margins like? (Obvious transition between normal and abnormal skin or blurred?)
- Remember to consider your signalment (age, breed, sex)
8
Q
WHen to worry based on cytologic findings about a nodule?
A
- Mitoses
- Hemorrhagic aspirate
9
Q
Basic diagnostics for nodules
A
- FNA/cytology
- Histopathology
- Culture from biopsy (bacterial, fungal, mycobacterial)
He recommends taking a sample for FNA then for biopsy and culture at the same time)
10
Q
What on cytology suggests infection?
A
- Pyogranulomatous inflammation
11
Q
How do you diagnose sterile disease?
A
- Exclude infection and neoplasia
12
Q
What are more common bacterial causes of single nodules?
A
- Staphylococcus
- Mycobacteria
- Nocardia/Actinomycosis
13
Q
Clinical signs of staphylococcus
A
- Furunculosis
- Botryomycosis (chronic bacterial disease)
14
Q
Etiology of canine leproid granuloma?
A
- Mycobacteria CLG
- Novel mycobacterial species that do not grow using standard methods
15
Q
Where are lesions restricted with canine leproid granuloma?
A
- Head and pinnae
16
Q
Diagnosis of canine leproid granuloma
A
- Demonstration of acid fast organisms on histopathology or cytology
17
Q
Appearance of acral lick dermatitis?
A
- Raised ulcerated firm mass over the distal extremity
18
Q
What causes acral lick dermatitis?
A
- Chronic licking
19
Q
What breeds get acral lick dermatitis?
A
- Large breed dogs
20
Q
Two rules of acral lick dermatitis?
A
- ALWAYS INFECTED
2. Secondary to something
21
Q
Inciting causes of acral lick dermatitis?
A
- Allergies**
- infection
- Prior surgery
- Foreign body
- Arthritis
- Previous trauma
- Neoplasia
- Behavioral
22
Q
Diagnosis of acral lick dermatitis?
A
- Scrape (demodicosis is a rule out)
- Cytology –> biopsy
- Culture (from biopsy; poor man’s culture is to prep with chlorhexidine, rinse with saline and squeeze contents)
- Radiography
- Look for an underlying cause!!**
23
Q
Treatment of acral lick dermatitis
A
- Treat underlying infection with 4-6 weeks of systemic antibiotics based on culture
- Identify the underlying cause
- +/- behavior modification to break the cycle
24
Q
Other treatment options for acral lick dermatitis
A
- Cryosurgery
- CO2 laser surgery
- Acupuncture
- Behavior consult
25
Fungal causes of nodules
- Dermatophyte
- Saprophytic fungi
- Pythium/lagenidium
- Sporotrichosis
- Blastomycosis
- Histoplasmosis
- Cryptoccosis
- Coccidioidomycosis
26
What is a kerion?
Dermatophyte furunculosis
27
Appearance of kerion
- Usually solitary nodule often on the face
28
What often causes kerions?
- Microsporum gypseum, a soil dermatophyte
| - Often a history of the dog sticking its face in the dirt
29
What class of fungi are pythiosis/lagenidiosis?
- Oomycetes
- Aquatic plant pathogens
- Not true fungi but saprophyte
30
Where is pythiosis or lagenidiosis found?
- Decaying wood and vegetable matter
31
Where is pythiosis or lagenidiosis typically found?
- Gulf coast states
| - WI, NJ, VA, CA, AZ KY have had diagnoses
32
Cytology of pythiosis or lagenidiosis?
- Pyogranulomatous with eosinophils
| - Hyphae hard to see
33
Biopsy of pythiosis or lagenidiosis?
- Silver stain required for Pythium
- Hyphae may invade blood vessels
- Granulomatous to pyogranulomatous dermatitis with eosinophils
- Hyphae may be found intracellularly in giant cells
- Hyphae are broad, thick-walled, and irregularly septate
- Hyphae of Lagenidium are larger than those of P. insidiosum
34
Other diagnostic tests for pythiosis or lagenidiosis?
- Culture
- Serology, PCR, IH
- In addition to the cytology and biopsy
35
Clinical signs of pythiosis?
Areas in contact with stagnant water most likely to be infected
- Lesions are usually solitary draining nodules on the lower extremities
36
Breed with increased incidence of pythiosis?
- German SHepherds
| - Lesions in cats and horses described too
37
Lagenidiosis - where have cases been identified?
- FL, LA, TX, TN, and IN
38
Clinical signs of lagenidiosis?
- Same as those described for pythiosis
| - Often quite aggressive
39
What is important to differentiate pythiosis and lagenidiosis (oomycetes) from?
- Zygomycosis (true fungal infections)
40
Culture of pythiosis/llagenidiosis?
- Isolation is difficult
- Requires production of sexual reproductive structures for species ID, which is tough
- Pythium can be identified on biopsy with immunoperoxidase technique
41
PCR and Pythium/Lagenidium
- Can identify Pythium and differentiate it
42
Is serology better for pythiosis or lagenidiosis?
- Pythiosis
| - AGID and ELISA
43
Treatment of pythiosis/lagenidiosis?
- Very difficult
- WIde surgical excision treatment of choice**
- Systemic therapy (itraconazole +/- terbinafine) for 2-4 months
- <25% response
- Agriculture fungicides (Caspofungin or Mefenoxam)
- Immunotherapy with anti-pythium vaccine
44
Dermatologic manifestation of Blastomycosis?
- little nodules
45
Appearance of blastomycosis on cytology or biopsy
- Characteristic halo
46
Skin lesions with histoplasmosis?
- Papular to nodular growths often located at the mucocutaneous junctions
47
Appearance of histoplasmosis on cytology or biopsy?
- See them within macrophages
48
Cryptococcosis appearance classic?
- Bulging of the hea and bridge of the nose
49
Appearance of Cryptococcus
- Capsule
50
What causes viral warts?
Papilloma virus
51
Who gets viral warts?
- young dogs
52
Where do viral warts occur often?
- Around oral mucosa
53
Treatment for viral warts
- Regress on their own (within ~3 months)
- Azithromycin
- Laser surgery
54
Why can viral warts recur?
- For the virus to take place, there has to be a penetrating trauma
- Goes directly to the basal cell layer and invades the immune system
- Carries with it the viral particle and grows little roots
- has a little stalk
55
Cell type origin of histiocytomas
- Langerhans cell origin
56
What are proposed theories for what a histiocytoma is?
- Tumor vs reactive hyperplasia
57
Who gets histiocytoma?
- Common in young dogs
| - Rare in cats
58
Clinical appearance of histiocytoma?
- Rapid growth
- Dome-shaped
- Alopecic
- 0.5 cm-1.5 cm
- May ulcerate
59
Clinical behavior of histiocytoma?
- Spontaneous regression in 1-3 months
| - Often looks worse just before remission
60
Locations of histiocytomas?
- Head, pinna, limbs, scrotum
61
Treatment for histiocytoma?
- Ignore or remove
| - Surgically remove if it's removing them
62
Diagnosis of histiocytoma
- Signalment
- Clinical appearance
- Cytology shows round cells (Histiocytes with mitoses or lymphocytes in regressing lesions)
- Histopathology
63
Five differentials for round cells?
- Lymphoma
- Mast cell Tumor
- TVT
- Histiocytoma
- Plasmacytoma
64
What is cutaneous histiocytosis?
- Nodular disease of dogs
65
Where do nodules occur with cutaneous histiocytosis?
- Dermis or SC fat of face, neck, back and trunk
| - May also occur in the nasal mucosa resulting in respiratory stridor
66
Appearance of nodules with cutaneous histiocytosis?
- ERythematous and nodular (raised)
67
Treatment of cutaneous histiocytosis
- Immunosupression (prednisone or dexamethasone)
- Doxycycline/niacinamide
- Cyclosporine
- Long term treatment usually needed
68
Histopath with cutaneous histiocytosis?
- Infiltrates of large histiocytic cells
69
What is a melanocytoma?
- Benign neoplasm from melanocytes
70
Who gets melanocytoma?
- Dogs, higher incidence in pigmented breeds
| - Rare in cats
71
Locations of melanocytoma
- Trunk
- Head (eyelids, muzzle)
- Extremities (between digits)
72
Clinical appearance of melanocytoma?
- Solitary
- Circumscribed
- Alopecic
- Non-ulcerated
- Dome-shaped
- Blue-black to dark brown in color
73
Clinical behavior of most melanocytomas?
- Most are benign
| - Can't always predict based on histopathology
74
Diagnosis of melanocytoma
- Cytology and histopathology
75
Treatment of melanocytoma?
- Surgical removal with clean margins
76
What is the cell type for trichoblastoma (basal cell tumor)?
- Primitive hair germ epithelium
77
Who gets trichoblastoma?
- Common in dogs and cats
78
What is the most common pigmented tumor of cats?
- Trihoblastoma
79
Where do dogs get trichoblastomas?
- head and neck
80
Where do cats get trichoblastomas?
- Cranial half of the trunk
81
Clinical appearance of trichoblastoma
- SOlitary
- Dome-shaped
- Firm
- 1-2cm
- Alopecic
- Ulcerated
- Melanotic
82
Clinical behavior of trichoblastoma
- Benign
83
Treatment of trichoblastoma
- Observe
| - Surgical excision (curative)
84
Sebaceous gland tumors in dogs vs cats - how common?
- Common in dogs
| - Uncommon in cats
85
What are the four types of sebaceous gland tumors and relative rarity of each?
1. Nodular sebaceous hyperplasia (most common)
2. Sebaceous adenoma (common)
3. Sebaceous epithelioma (common but often ulcerates and bleeds)
4. Sebaceous adenocarcinoma (rare)
86
Location of sebaceous gland tumors
- Trunk
- Limbs
- Eyelids
- head
87
CLinical appearance of sebaceous gland tumors
- Wart-like or cauliflower like
- Pinkish to orangish
- may be melanotic or ulcerated
88
Clinical behavior of sebaceous gland tumors
- Benign
- new adenomas or hyperplasias will develop if you might complicate them?remove
- Adenocarcinoma and epithelioma rarely metastasize
89
What can happen to sebbaceous gland tumors that might complicate them?
- Can become colonized with Malassezia or bacteria
- Can be pruritic
- ID with surface cytology***
- Address the infections with topical treatments
90
Diagnosis of sebaceous gland tumors
- Clinical appearance usually
- Cytology
- Histopathology (suspicious of epithelioma or adenocarcinoma)
91
Treatment of sebaceous gland tumors
- Observe
| - Surgically excise
92
When might you be more suspicious that it's a sebaceous adenocarcinoma?
- Usually more ulcerated and inflamed with poorly defined borders
93
What is the doctor word for a skin tag?
- Acrochordon
94
What is a nevus?
Hamartoma
95
Treatment for acrochordon
- Single ones can be lasered off or excised, but if there are a lot it would take a very long time
96
What is a follicular hamartoma?
- Hairy mole
97
Perianal adenoma?
- Looks like a smooth, alopecic mass in the perianal region
98
Which category of nodules do many syndromes fit?
- Sterile
99
What is the most likely pathogenesis of sterile nodules?
- Most likely immune-mediated, but the pathogenesis is truthfully unknown
100
How do you diagnose sterile causes?
- Exclusion!
101
What are some dfdx for pyogranulomatous inflammation?
- Infectious until proven otherwise
| - Could be sterile
102
How do you determine if pyogranulomatous inflammation is infectious or not?
- Negative tissue cultures
- No organisms seen on histopathology
- Lack of response to abx
103
Treatment recommendations for sterile disease?
- Long duration of therapy
- Doxycycline (niacinamide)
- Immunosuppressive steroids - prednisone or dexamethasone
- Cyclosporine
- Once in remission, slow taper over several months
104
What to do if something you suspect is sterile disease stops improving?
- Repeat cytology +/- biopsy and cultures
105
Dfdx for sterile nodules?
- Eosinophilic furunculosis
- Juvenile cellulitis
- Sterile nodular panniculitis**
- Sterile pyogranuloma/pyogranuloma syndrome
- Follicular cysts
- Perianal fistulas
- metatarsal fistulas
106
What is most likely cause of eosinophilic furunculosis?
- Arthropod or insect bite most likely
107
Onset of canine eosinophilic furunculosis
- Sudden
108
Treatment of canine eosinophilic furunculosis
- Often steroid responsive
109
Recurrence of canine eosinophilic furunculosis
- Rare
110
Who gets juvenile cellulitis?
- Young puppies usually, but may occur in adult dogs
| - Dachshunds, Goldens, Pointers often
111
Appearance of juvenile cellulitis?
- Pustular to nodular disease of young puppies
112
When does juvenile cellulitis tend to occur?
- Following recent vaccination
113
What is the cause of juvenile cellulitis
- Unknown
- It does occasionally develop following recent vaccination, but attempts to reproduce the disease with a vaccine or virus have failed
114
Clinical signs of juvenile cellulitis
- Pustular to nodular disease
- Primarily affects face and head, especially muzzle and periocular region
- Ears, anus, and prepuce may also be affected
- Crusting on the muzzle (with a nodule underneath)
- Often a LARGE submandibular lymphadenopathy
- Occasionally sterile abscess at the site of vaccination
- reports of this occurring with HOD
115
Treatment for juvenile cellulitis
- Immunosuppression (but usually need concurrent ABs)
- Doxycycline/niacinamide
- Cyclosporine
- Slowly taper off meds once in remission
116
Diagnosis of juvenile cellulitis
- really needs a biopsy
| - Remember you need to rule out infectious causes!
117
Sterile nodular panniculitis characteristics of disease
- Solitary or multiple SC nodules that ulcerate and discharge an oily, bloody exudate
- Lesions occur anywhere
118
Clinical signs of sterile nodular panniculitis
- Dogs may be systemically ill (anorexia, lethargy, fever)
| - Serum alkaline phosphatase may be elevated (liver process or pancreatitis associated?)
119
Who is predisposed to sterile nodular panniculitis?
- Dachshunds, Maltese
120
Treatment for sterile nodular panniculitis
- First rule out infection with cytology/culture/biopsy
- Immunosuppression
- Doxycycline/niacinamide
- Cyclosporine
- Vitamin E
- can sometimes taper off all meds once in remission
121
Dermatologic lesions with sterile nodular panniculitis
- Solitary or multiple deep-seated cutaneous nodules
- Frequently ulcerate and discharge and will leak blood yexudate
- Lesions vary in locaiton and size, with majority occurring over the ventral lateral chest, neck, and abdomen
- Dogs may appear systemically ill with decreased appetite, lethargy, and fever
122
Major dfdx for sterile nodular panniculitis
- Bacterial or fungal infection
| - Need to rule out with cytology, histopathology, and sterile cultures
123
What is sterile histiocytic disease?
- Periadnexal multinodular granulomatous dermatosis
| - Sterile pyogranuloma/granuloma syndrome
124
Derm lesions with periadnexal multinodular granulomatous dermatitis
- Pyogranuloma/granuloma syndrome
| - Multiple nodules of the head, pinna, and paws
125
Histopathologic pattern of periadnexal multinodular granulomatous dermatitis
- Characteristic
| - Histiocytes
126
Treatment of periadnexal multinodular granulomatous dermatitis
- Immunosuppression
- after ruling out bacterial and fungal disease
- Steroid responsive at immune suppressive doses
- Some may respond to cyclosporine, doxycycline/niacinamide
127
Follicular cyst/epidermal inclusoin cyst appearance
- Dermal nodules sometimes within a pore
| - Thick material inside (brown/gray thick per disease; toothpaste like)
128
Complications of follicular cyst/epidermal inclusion cyst
- Can create inflammatory reaction if ruptured
| - Can become secondarily infected
129
Diagnosis of follicular cyst/epidermal inclusion cyst
- Biopsy
130
Treatment of follicular cyst/epidermal inclusion cyst
- Surgical excision (must pull out the lining of the cyst to be curative)
- Retinoids/Vitamin A?
- Could ignore
- Sudden occurrence of many nodules - rule out endocrine!
131
What is intracutaneous cornifying epithelioma?
- Form of follicular cyst or epidermal inclusion cysts
- Usually multiple and can be quite large
- Treat with surgical incision
132
Which breeds get intracutaneous cornifying epithelioma?
- Keeshonds and German Shepherds
133
Appearance of apocrine cysts, and what happens if you pop it?
- Fluid cyst
- Will fill back up if deflated
- Need to remove it to prevent recurrence
134
Appearance of perianal fistulas or anal furunculosis?
- Draining lesions around the anus
- Shallow, blind-ended sinuses
- Not associated with anal sacs
- Often very painful
135
Breed predisposition for perianal fistulas?
- German SHepherds or Irish Setters
136
Etiology of Perianal Fistulas
- Likely immune-mediated but full mechanism not well-elucidated
137
Clinical signs of perianal fistulas
- Clinical signs
- Cytology
- +/- biopsy (often quite painful and can't suture well)
- Rectal examination (check for anal sac involvement)
138
Treatment for perianal fistulas
- Cyclosporine (+/- ketoconazole)
- Tacrolimus (better tissue penetration)
- Prednisone
- Food trial
- Antibiotics
139
Prognosis for perianal fistulas
- Good for control
140
Surgery for perianal fistulas?
- Reserved for refractory cases or with secondary anal sac involvement
141
Who gets focal metatarsal fistulas?
- German Shepherds
| - Also reported in Weimaraner, Greyhound, Doberman
142
Clinical signs of focal metatarsal fistulas
- Asymptomatic to lame
143
Cause of focal metatarsal fistulas
- Unknown
144
Treatment of focal metatarsal fistulas
- Response to immunosuppression
- Steroids
- Tacrolimus
- Cyclosporine
- Doxycycline/niacinamide
