1. Surgical treatment of vaginal leiomyosarcoma in a mixed breed dog
Lisa Benson
Cornell University
College of Veterinary Medicine
Class of 2014
4/16/14

2. History 11 year old FS Mixed Breed Dog
Presenting Complaint: Mass of the Colon
Tenesmus x 2 weeks: 3 Days Lactulose
Rapid Growth
Cough x 2 weeks
Progressive Right Hind Limb Lameness
Bilateral Hind Limb Lameness - Chronic

3. History 11 year old FS Mixed Breed Dog
Presenting Complaint: Mass of the Colon
Tenesmus x 2 weeks: 3 Days Lactulose
Rapid Growth
Cough x 2 weeks
Progressive Right Hind Limb Lameness
Bilateral Hind Limb Lameness - Chronic

4. Physical exam: Abnormalities
Very Nervous
Sensitive Hind Limbs/Caudal Trunk
Right Hind Limb Lameness: Lateral Extension
Left Hind Limb: Firm, Movable Subcutaneous Mass
Digital Rectal Palpation
Hard, Bony Mass: Left Ventral Pelvic Canal
Firm, Rounded Mass: Right Ventrolateral Pelvic Canal
Complete Obstruction
Painful hindlimbs and caudal trunk—indications. RHL Extension, cranio laterally extended during sitting and recumbency, and SWINGS leg laterally during ambulation

5. Problem list Chronic, Mild Bilateral Hind Limb Lameness: Lifetime
Mass – Pelvic Canal
Progressive Right Hind Limb Lameness
Tenesmus
Cough
Left Hind Limb Subcutaneous Mass

6. Problem list Mass – Pelvic Canal Tenesmus
Progressive Right Hind Limb Lameness
Cough (?)
Left Hind Limb Subcutaneous Mass (?)

7. Differential diagnoses
Broad
Pelvic Mass Differential Diagnosis
Tumor or Abscess Arising from the Following:
1. Rectum
2. Vagina
3. Urethra
4. Bony Pelvis

8. Diagnostics Bloodwork: Complete Blood Count/Blood Chemistry:
Unremarkable
Imaging: Full Body CT Scan
Thorax
Abdomen
Pelvic Canal
Proximal Hind limbs

9. Ct scan: Sagittal image
Mass
Cranial
Caudal
Orient! — Sagittal Plane
Bladder
Heart

10. Ct scan: Sagittal image
Colon
Urethra

11. Ct scan: sagittal image

12. Ct scan: sagittal image

13. Ct scan: frontal image
Frontal plane

14. Ct scan: transverse image
Transverse Plane

15. CT Scan: Findings Thorax and Abdomen: Negative for Metastasis
Pelvis: Large Mass – Sciatic n. Compression
Vaginal Origin – Not Colon
Incidental:
Left Hind limb Mass: Lipoma
Hip and Shoulder Osteoarthritis - Mild
BIG PICTURE: LARGE VAGINAL MASS, Likely cause of RH lameness but not her cough. Thorax/Abd: Negative for Mets—Cough no longer big concern—dry heat lately
Pelvis: LARGE mass, Inability to defecate attributed to mass
left dorsal compression of rectum = Hard bony “mass” left ventral rectum = I really palpated ischium.
Ventral displacement of Urethra.
Mass Continuous w vagina and unlikely to be arising from rectum.
RHL pain was possibly due to Sciatic N. compression
LHL SQ mass determined to be a lipoma (Neg for Neoplasia)
Osteoarthritis: explains the chronic mild lameness owners noted for most of her life
Hip OA was MILD and UNLIKELY cause of RHL pain

16. Differential diagnoses
Vaginal Mass: Neoplasia vs. Inflammation
Neoplasia
Benign: Leiomyoma
Malignant: Leiomyosarcoma
Inflammation: Stump Pyometra
Less Likely: 10.5 years post Spay
No Signs of Ovarian Remnant

17. Leiomyoma vs leiomyosarcoma
Smooth Muscle Tumors: GI more common location
Lack of Vaginal Cases and Information
2.4% - 3% of ALL Canine Tumors are from Reproductive System
83% Benign (Leiomyoma Most Common)
Intact Females
Sometimes metastatic, and if excision was incomplete = indication for RT. We don’t have data on the impact on survival with adjuvant therapy.  “The impact of adjuvant radiation or chemotherapy on outcome is unknown.”

18. Leiomyoma vs leiomyosarcoma
Leiomyosarcomas – Hormonally Independent
Complete Excision (Vaginal): Curative
Moderate Risk Metastasis/Recurrence
Impact of Adjuvant Radiation/Chemotherapy:
Outcome on Survival Unknown
Sometimes metastatic, and if excision was incomplete = indication for RT. We don’t have data on the impact on survival with adjuvant therapy.  “The impact of adjuvant radiation or chemotherapy on outcome is unknown.”

19. plan Surgery: Mass Excision Episiotomy +/- Abdominal Exploratory
Pubic Osteotomy
Partial Vaginectomy
Histopathology for Definitive Diagnosis

20. Surgery: Neuroanatomy
Pudendal n.
Pelvic n.
Perineal n.
Hypogastric n.
Pelvic Plexus
Orientation: Cranial; Caudal; Bladder; Desc Colon; Vagina.
Hypogastric N. Cranial= sympathetic innervation of the bladder- On LATERAL SURFACE OF RECTUM
Pelvic Plexus ON LATERAL SURFACE OF RECTUM comes off of the Pelvic n- (axons SC S1-S3): innervation of bladder, rectum, Urethra (ext sphincters); genitalia.
pudendal n. comes off of pelvic plexus moving caudally—Perineal n and a branches off of pudendal n which branches off of the pelvic NERVE (not plexus)
Our main concern: Avoid damaging these nerves. Closely associated with the area we’ll be dissecting, to excise the mass completely—potential for permanent urinary incontinence, rectal incontinence (lesser concern?).
Also: Risk of perforated bowel: descending colon or rectum may perforate, cause sepsis with anaerobic bacteria. (pre-operative (24 hrs in advance) started oral Clindamycin, continued perioperatively and post operatively IV. Plus TGH oral x 2 weeks.
(Evans, de LaHunta)

21. Surgery: Episiotomy
Orientation: Dorsal, Ventral. Standard episiotomy - Full thickness incision. attempt to access tumor and remove it. (Less invasive)

22. surgery Mass Orange Catheter: Vaginal Canal
White Catheter: Urethral Papilla
Palpated mass in vaginal canal– too cranial to remove it via episiotomy.

23. Surgery: Abdominal Colon Random Loop of Intestine Uterine Remnant
Orient - Pulled bladder caudally; Find uterine remnant and mass. See that a pelvic approach necessary –it’s smack in the middle of the pelvic canal---Osteotomy!
Urinary Bladder

24. Surgery: Mass located Mass Pubic Symphysis
Pulled bladder cranially—urethra, palpable mass continues deep to Pubic Symphysis
Pubic Symphysis

25. Surgery: pubic osteotomy
Cleared Pubic Bone: Transected Adductor mm and Gracilis mm with cautery at point of origin along pubic symphysis. Point out holes drilled for orthopedic wire to close pelvis later—22 gauge. Three transections— 2 cranial to caudal cuts: 1 in right and 1 in left arm of pubis, then a transection perpendicular and CRANIAL to the first two . Protected obturator n with miller sens when drilling.

26. Surgery: Mass Excision
Pubic symphysis flipped caudally—See OBTURATOR MUSCLE on inside of the bone, we left intact.Mass easier to visualiize and dissect away from tissues—CAREFUL OF NERVES

27. SURgery: Mass Excision
Pelvic Plexus
Mass within vaginal wall. NERVES: Pelvic Plexus —innervating bladder, rectum, urethra. Pudendal n from pelvic n innervating external urethral sphincter. Hypogastric n, sympathetic nerves also along lateral wall of the rectum too—MUST DELICATELY DISSECT AWAY MASS, dissect Vagina off rectum. –incontinence Risk. Compressed (by mass) for a long time!

28. Surgery: Vaginal Wall Reflected
Vaginal Wall reflected—see mass

29. Surgery: Mass Excision
Orient Cranial and Caudal: Almost out!

30. Surgery: Dissect Carefully
Last remnant of attachment to vaginal wall. Vaginal tissue thin, compromised. Partial vaginectomy. Total vaginectomy was not necessary—--avoid possible harm to nerves.

31. Surgery: repair osteotomy
Closed pubic bones with 22 gauge orthopedic wire placed into the predrilled holes- circlage technique to stabilize bony pelvis. Reattached gracilis and adductor muscles. Closed vagina where we’d opened it to get the mass out—mass was attached to dorsal wall. Closed the dorsal (and ventral ) defects of vaginal wall– continuous 3-0 PDS. Repaired 2 cm area of compromised rectal serosa w/3-0 PDS (mass compression). THEN STANDARD ABDOMINAL closure after warm abdominal lavage. SUMITTED TISSUE TO PATHOLOGY…

32. Surgery: Mass Removed
SUBMITTED FOR HISTOPATHOLOGY!

33. histopathology
PALE ISCHEMIC CHANGES (clear spaces BLACK ARROW)) and inflammation: segmented neutrophils (more cellular areas: BLUE ARROW). Loss of cellular and nuclear detail. Small areas of necrosis, hemorrhage, inflammation.

34. histopathology
This slide highlights the disorganization and irregular orientation of neoplastic cells. Smooth Muscle tumors are disorganized , interacting at odd angles. Aniscokaryosis: Nuclei changing from normal cigar shaped nuclei to circular. This tissue is not “calm enough” to be a leiomyoma, though it is acting more ”well-behaved” than some leiomyosarcomas/malignant tumors.

35. Histopathology: Leiomyosarcoma
Blue Arrow: Mitotic Figure. Originally this report was read out as 1-2 MFs per 10 HPF, but reviewed it again and it was more like 3-4 per 10 HPF. –Mild but more than typical leiomyoma. Acting more like a leioMYOMA, but d/t necrosis, inflammation, LACK OF ORGANIZATION, loss of cellular and nuclear detail, anisokaryosis, anisocytosis: which are all features of a MALIGNANT TUMOR: it is not an entirely “nice” benign leiomyoma. Though there is a grey zone and this will likely be a well-behaved tumor. Normal muscle tissue - around tumor’s full circumference, indicating likely fully excised (can’t obtain wide margins in this type location). So it was read out to be a Leiomysarcoma—to err on the side of caution.

36. Post surgical care Antibiotic: Clindamycin IV 11mg/kg BID
Pain Management:
Fentanyl CRI 2 mcg/kg/hr  Patch
Dexmedetomidine IV 15 mcg PRN Q4h
Carprofen 2 mg/kg BID
Gabapentin 3 mg/kg BID
Tramadol 3 mg/kg PRN
Supportive Care:
IV Fluids, Ice and Check Tegaderm Q6h
BACK TO OUR PATIENT…

37. Post surgical care Main Concern: Urinary Incontinence
Monitor for Urination, Check for Leakage
1 Day Post Surgery: Steady Controlled Stream
Discharged That Evening
Discharged to her owners after 1 full day in hospital for post operative care. Walked very well, urinated “great stream!” less than 24 hours post surgery.

38. update 2 week Recheck – Tenesmus Gave Pumpkin and Lactulose
Lactulose Overdose  Diarrhea Once
Owners “Very Pleased”
No Signs Now
Bladder Control 7 hours (Reduced)
Lactulose PO 5 ml BID
Out at midnight and by 7am—Does well, no accidents (BUT 7 hours is her limit—She can’t hold her bladder longer (and she could before surgery).
Managed on Lactulose: 5 ml (1 teaspooon) BID. The Owner says he “doesn’t dare” stop for fear of more tenesmus. He has found the right dose—no Diarrhea (No tenesmus—just normal stool).

39. Costs Combined Total Costs Dollar Amount Administrative Management
697.00
Anesthesia
818.50
Clinical Pathology
67.88
Imaging
832.20
Professional Services
100.00
Hospitalization/Inpatient Care
595.00
All Supplies and Materials
616.55
Pharmacy
199.73
Grand Total
$ 3,926.86
Total costs: Just shy of $4,000

40. references
Buergelt, Claus D. Color Atlas of Reproductive Pathology of Domestic Animals. St. Louis: Mosby Print.
Evans, H., de Lahunta, A. Miller's Anatomy of the Dog. 4th Ed. St. Louis: Elsevier Saunders Print.
Maxie, M G, K V. F. Jubb, P C. Kennedy, and Nigel Palmer. Jubb, Kennedy, and Palmer's Pathology of Domestic Animals. Edinburgh: Elsevier Saunders Print.
McEntee, Kenneth. Reproductive Pathology of Domestic Mammals. San Diego: Academic Press Print.
Nelissen, P, and RA White. "Subtotal Vaginectomy for Management of Extensive Vaginal Disease in 11 Dogs." Veterinary Surgery : Vs (2012): Print
North, Susan M, and Tania A. Banks. Small Animal Oncology: An Introduction. Edinburgh: Elsevier Saunders Print.
Thacher, C, and RL Bradley. "Vulvar and Vaginal Tumors in the Dog: a Retrospective Study." Journal of the American Veterinary Medical Association (1983): Print.
Tobias, Karen M, and Spencer A. Johnston. Veterinary Surgery: Small Animal. St. Louis, Mo: Elsevier Print.
Weissman A, D Jiménez, B Torres, K Cornell, and SP Holmes "Canine Vaginal Leiomyoma Diagnosed by CT Vaginourethrography". Journal of the American Animal Hospital Association. 49, no. 6.
Withrow, Stephen J, and David M. Vail. Withrow & Macewen's Small Animal Clinical Oncology. St. Louis: Saunders Elsevier Print.

41. Thank you! Dr. Flanders Dr. Hume Dr. Ruby Dr. Asakawa
The Class of 2014
My Family
My Advisors, My Class, and My Family