CAMS L72: Ear and Anal Sacs – Flashcards
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CAMS L72:
What are the important surgical anatomical structures of:
1. external ear
2. middle ear
3. inner ear
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1. pinna, vertical and horizontal canal
2. tympanic bulla
3. cochlea and ossicles
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CAMS L72:
The greater auricular artery, the main vascular supply to the ear, is a branch of the ____ ____ artery. It arises adjacent to the bulla
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external carotid
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CAMS L72:
Which nerve supplies the motor innervation of the ear? It exits the skull via the stylomastoid foramen and crosses immediately ventral to the external ear canal
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facial nerve
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CAMS L72:
Sensory information in the ear is carries by branches of which nerve?
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vagus
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CAMS L72:
How is the middle ear of the cat different from the dog's?
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more distinct separation of the chambers into a larger ventral cavity and a smaller dorsal cavity, nearly completely separated by a bony septum with a small slit-like communication between them
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CAMS L72:
Pre-surgical assessment:
1. Perform an otoscopic exam to determine what about the tympanic membrane?
2. cytology
3. imaging- what is the best imaging modality for the ear?
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1. if it's intact and whether it's grossly normal
3. CT
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CAMS L72:
Aural hematoma:
1. caused by...?
2. What happens if it's not treated?
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1. vigorous head shaking secondary to acute or chronic otitis external or foreign bodies- the shear forces result in the creation of dead space which will be filled by blood from the ruptured of vessels
2. hematoma organises and is replaced by granulation tissue. Myofibroblasts result in contraction and subsequent disfigurement of the pinna
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CAMS L72:
Aural hematoma- how is it treated?
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1.Drain hematoma by a variety of incision on inner ear surface
2. Close dead space by placement of multiple parallel (to each other and to the long axis of the pinna) rows of sutures. It also prevents damage to the vascular supply of the pinna
3. Bandage the ear for 5-7 days to prevent further trauma
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CAMS L72:
Ear laceration- how is it treated?
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-If only one skin surface is involved, lavage, debride and allow to heal via primary repair or second intention
-When full thickness, primary repair is indicated. Suture both skin surfaces and cartilage layer
-simple interrupted sutures are used to reappose the remaining skin surface
-bandage ears for protection
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CAMS L72:
What are the more frequent types of neoplasms that affect the pinna/external ear?
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SCC
Hemangioma/hemangiosarcoma
basal cell tumor
mast cell tumor
histiocytoma
sebaceous adenoma
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CAMS L72:
A white cat is brought in with chronic non-healing wounds on his ears. These wounds are cracked and bleeding. What is a ddx that affects white cats 13.4x as often as colored cats?
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SCC
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CAMS L72:
How is SCC on the ear treated?
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-If necessary, surgical removal (partial or complete pinnectomy +/- vertical canal resection)
-Small lesions may be treated via cryotherapy, laser ablation or local radiation therapy
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CAMS L72:
Which of the following regarding subtotal and total pinnectomy is false?
1. excise the tissue to be removed
2. pull skin on the convex surface of the pinna over the edge of the cartilage and suture 4-0 or 5-0 monofilament, absorbable suture in a simple continuous pattern
3. ink the cut edges for histopathology margin assessment for neoplastic disease cases
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2. pull skin on the convex surface of the pinna over the edge of the cartilage and suture 4-0 or 5-0 monofilament, NON-ABSORBABLE suture in a simple continuous pattern
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CAMS L72:
Which of the following is false about indications for lateral wall resection?
1. to facilitate management of otitis externa that is controlled with medication
2. removal of benign neoplasia of external canal
3. if stenosis of canal is present or the dog is a Cocker Spaniel
4. success rate is 35-50%
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3. NOT INDICATED if stenosis of canal is present or the dog is a Cocker Spaniel
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CAMS L72:
Total ear canal ablation + lateral bulla osteotomy (LBO) is indicated under what circumstances?
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end stage otitis externa/media
When the vertical and horizontal canals are hyper plastic and stenotic
*LBO drains bulla
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CAMS L72:
What are the potential complications of total ear canal ablation + lateral bulla osteotomy?
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facial nerve damage
hemorrhage
some hearing loss after surgery
fistulation if tissue left in situ
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CAMS L72:
Anal sacculectomy is indicated for recurrent anal sacculitis/impaction/abscess and neoplasia.
-when would you use the open technique?
-when would you use the closed technique?
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-open technique for inflammatory conditions
-closed technique for neoplasia
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CAMS L72:
10 yo intact male pug has a nodular mass in his perianal region. It is possibly ulcerated and bleeding.
Results:
*FNA- hepatoid cells (cells that look similar to hepatocytes that are found in perianal gland tumors)
*thoracic rads- within normal limits (WNL)
*rectal palpation- no palpable sublumbar node enlargement
*palpation of mass- freely movable
WHAT IS THE MOST LIKELY DIAGNOSIS?
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perianal adenoma
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CAMS L72:
1. What is the most common perianal tumor in the intact male?
2. What are other names for it?
3. What is it dependent on?
4. This tumor is usually concurrent with which other tumor?
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1. Perianal adenoma
2. hepatoid or circumanal gland tumor
3. androgens
4. testicular tumor (interstitial tumor)
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CAMS L72:
Describe the typical behavior and appearance of a perianal adenoma?
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slow-growing
non-painful
freely moveable
+/- ulcerated
may occur on tail head, prepuce or scrotum
exists in a nodular and diffuse form
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CAMS L72:
What are the different ways of treating a perianal adenoma?
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conservative resection + castration
castration alone for diffuse form
castration + cryosurgery for small lesions
*always submit for histopathology
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CAMS L72:
What is the prognosis for perianal adenoma?
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good
>90% cured with castration and mass removal
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CAMS L72:
9 yo male castrated mixed breed dog has large mass in the perianal region. The shape of it is crazy (as opposed to circular) and appears to be somewhat ulcerated.
Results:
*FNA- hepatoid cells
*thoracic rads- WNL
*rectal palpation- no palpable sub lumbar node enlargement
*palpation of mass- fixed, invasion into deeper tissue
WHAT IS THE MOST LIKELY DIAGNOSIS?
WITH A POTENTIAL DIAGNOSIS WHAT IS THE NEXT STEP YOU WILL TAKE?
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perineal adenocarcinoma
biopsy
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CAMS L72:
With a diagnosis of perineal adenocarcinoma, what does your diagnostic work up consist of?
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-caudal abdominal rads or u/s
-rectal exam
-chest rads for metastasis
-+/- advanced imaging to assess degree of invasiveness
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CAMS L72:
What is the typical behavior and appearance of perineal adenocarcinoma?
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-can look similar to perianal ademona and cytology may not differentiate them
-usually more rapidly growing, invasive and possible painful, as compared to perianal adenoma
-occurs in intact males, castrate males or females b/c it's not androgen dependent
-metastasises to sublumbar LNs
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CAMS L72:
What is the treatment of perineal adenocarcinoma?
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-aggressive surgical removal with margins (use radiation therapy if margins are incomplete)
**they do NOT respond to castration
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CAMS L72:
What is the prognosis of perineal adenocarcinoma?
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a small amount will have LN metastasis
local recurrence common (even w/ sx)
*2 yr survival* if <5cm diam + no metastasis
*2 mo survival* w/ metastasis to LNs or lungs
excellent LOCAL control with surgery or surgery + XRT
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CAMS L72:
7yo F/S Keeshound
-large subq mass in R perineal region
-straining to defecate
-weight loss
-PU/PD
-lethargic
Results:
FNA- carcinoma cells
thoracic rads- WNL
Ab u/s- multiple engaged sublumbar LNs
Rectal- soft ball-sized ass, right side, firmly attached
Chem- Ca2+= 16mg/dl, BUN= 45 mg/dl, Creat= 2.5 mg/dl, albumin= 3.5 mg/dl
U/A= SG 1.008
WHAT IS THE MOST LIKELY DIAGNOSIS?
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Anal Sac Adenocarcinoma
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CAMS L72:
Anal sac adenocarcinoma
-does it tend to be invasive?
-what is a paraneoplastic syndrome?
-female or male?
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yes- invasive
hypercalcemia (hypercalcemia of malignancy)
females more likely
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CAMS L72:
Anal sac adenocarcinoma tx
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correct hypercalcemia first (before anesthesia/sx)
excise with wide surgical margins along with enlarged sublumbar LNs
