Persistent Vulvar Hemorrhage Secondary to Vaginal Hemangioma in Dogs
Two young female dogs were presented with a chronic history of persistent vulvar hemorrhage. Vaginoscopy was ultimately used to locate bleeding vaginal masses near the urethral papilla. In both cases, episiotomy was performed to resect the mass, and hemangioma was diagnosed histologically. These tumors caused persistent vaginal bleeding; they were difficult to diagnose without vaginoscopy and lavage; and surgical excision was curative in at least one case.
Introduction
Cyclical, estrus-related vulvar hemorrhage is normal in unspayed female dogs; it originates from the diapedesis of red blood cells (RBCs) across the endometrial lining of the uterus.1 Bleeding will subside permanently following successful ovariohysterectomy, as the influence of ovarian hormones dissipates. Ovarian remnants inadvertently left during ovariohysterectomy can elicit a recurrence of proestral bleeding, requiring a second operative procedure to remove the residual tissue.2 Continuous vulvar bleeding in properly neutered females is uncommon.1
Vaginal tumors have been reported in 0.85% to 3% of tumor-bearing animals.3–5 Noninfectious neoplasms are usually seen in geriatric, intact female dogs, and benign leiomyomas and fibromas predominate.3–6 The most common clinical sign associated with these masses is perineal swelling or a visible mass protruding from the vulva.3,4,6 In up to 30% of the cases, vaginal bleeding or discharge was noted.6 The differential diagnoses for vulvar hemorrhage also include coagulopathies, malignant vaginal neoplasia, transmissible venereal tumor (TVT), uterine stump granuloma, stump pyometra, uterine artery erosion secondary to ovariohysterectomy ligatures, urethritis, hematuria, and urinary neoplasia.1,2,6–11
To the authors’ knowledge, this is the first report to describe the diagnosis and management of persistent vulvar hemorrhage secondary to vascular tumor diagnosed as vaginal hemangioma in dogs.
Case Reports
Case No. 1
An 18-month-old, 29-kg, spayed female Labrador retriever was presented to the Virginia-Maryland Regional College of Veterinary Medicine (VMRCVM) with a 4-month history of persistent vulvar bleeding. The dog had been spayed at 10 months of age. On physical examination, the dog had frank blood dripping from the vulva, the mucous membranes were pink, and the remainder of the examination was within normal limits. The packed cell volume (PCV) was 39% (reference range 37% to 55%); white blood cell (WBC) count was 8469 cells/μL (reference range 5000 to 13,000 cells/μL); and total protein was 6.2 g/dL (reference range 5.5 to 7.5 g/dL). No macro- or microscopic abnormalities were noted on urinalysis. Vaginoscopy was performed with a proctoscope, and clotted blood was noted in the cranial vaginal vault. This was flushed out with sterile saline, revealing a red, fleshy, raised 1.0 × 0.7-cm mass at the vestibulovaginal junction lateral to the urethral opening. Fresh blood was visualized originating from this mass.
The dog was anesthetized, and an episiotomy was performed following surgical preparation of the perineum. The urethra was catheterizeda for identification, and the mass was resected with wide margins. The vaginal wall defect was sutured closed, and the remainder of the closure was routine.
By the following morning, the dog had a mild amount of serosanguinous vulvar discharge, but the hemorrhage had resolved. A vaginal cavernous hemangioma in the submucosa was diagnosed based on histopathological analysis. The dog was lost to follow-up.
Case No. 2
An 11-month-old, 25-kg, intact female American Staffordshire terrier was presented to the referring veterinarian for vulvar bleeding that had become progressively heavier over a 4-week period. Presurgical PCV was 11%; the leukogram and platelet count were within normal limits. The animal was transfused with packed RBCs without experiencing any adverse transfusion reactions. A routine ovariohysterectomy was performed. The dog recovered uneventfully from the surgery.
During two subsequent evaluations by the referring veterinarian at 1 and 2 weeks postoperatively, continued heavy vulvar hemorrhage and a microcytic, hypochromic anemia (PCV of 15.8% and 14.2%, respectively) were seen. The hemorrhage persisted, and the dog was referred to an internal medicine specialist for further diagnostic evaluation. Abdominal ultrasonography and a coagulation panel were within normal limits. Serum progesterone levels of <0.1 ng/mL (reference range for anestrus <0.5 ng/mL) indicated anestrus with no active ovarian luteal tissue present. A digital vaginal examination showed no evidence of foreign bodies or palpable tumors. During vaginoscopy, only clotted blood was present within the vagina. A PCV of 10.7% necessitated a whole blood transfusion using a universal donor; however, following transfusion, the dog developed clinical signs consistent with a severe transfusion reaction, which resolved with supportive care.
The dog was referred to the VMRCVM with a cumulative 10-week history of vulvar bleeding with no obvious diagnosis. An abdominal ultrasound examination revealed a small uterine stump with well-defined margins, no abnormal thickening of the uterine wall, and a minimal amount of fluid in the remnant lumen. No evidence of ovarian remnants or other abnormalities were noted. Vaginoscopy did not reveal the source of bleeding, and no abnormalities were identified on vaginal cytology. The PCV at this time was 17%. Because of the prior transfusion reaction, a blood crossmatch was performed.All major and minor crossmatch groups were incompatible; thus, Oxyglobinb was used to increase tissue oxygenation perioperatively.
As the source of hemorrhage could not be found in the urinary system or distal to the cervix, abdominal exploration was performed through a ventral midline celiotomy incision. No sources of bleeding or ovarian remnants were identified, and each uterine artery was again individually ligated. The distal portion of the uterine stump was excised following double circumferential ligation. Closure was routine. The excised tissue was submitted for histopathological examination, which was later found to be normal.
Continued vulvar hemorrhage was noted immediately following surgery. Vaginal examination was repeated with a rigid proctoscope, and saline lavage and suction were applied to remove the blood clots. A small, hemorrhaging, purplish, exophytic mass was revealed in the right dorsolateral vaginal wall. The dog was reanesthetized and returned to surgery the same day. An additional 120 mL per hour of Oxyglobinb was administered intraoperatively. A standard episiotomy was performed following surgical preparation of the perineum. The urinary bladder was catheterized with a urinary cathetera to delineate the urethra. The mass, situated in the right dorsolateral wall at the vestibulovaginal junction, measured 1.0 × 0.5 × 0.5 cm in size. The mass was sharply excised with a 1.0-cm visual margin, including the underlying muscle. The vaginal wall was closed with 3-0 polydioxanone,c and the episiotomy closure was routine. The urinary catheter was left in place for 24 hours to prevent urinary obstruction from potential postoperative swelling, as well as to monitor urine output.
Recovery from the second anesthetic episode was uneventful. The following morning, the PCV was 18%, and no vulvar bleeding was noted except for a minimal serosanguineous discharge from the episiotomy incision. The dog continued to recover well and was discharged 2 days postoperatively with no evidence of vulvar bleeding on examination 1 week after surgery. Telephone conversation with the owner at 8 months postoperatively revealed a normal, healthy dog with no vulvar discharge.
Histological examination of the vaginal mass revealed areas of thin-walled vascular spaces in the submucosa that contained erythrocytes and, in some areas, thrombi [Figures 1, 2]. The vascular spaces were lined with flattened, morphologically well-differentiated endothelial cells. No connections between the spaces, no capillary buds, and no mitotic figures were observable. Hemangioma was diagnosed.
Discussion
Bleeding from the vulva is an unusual clinical finding in dogs that are not in ovarian-influenced proestrus/estrus.1 The origin of the hemorrhage in ovariohysterectomized females, as in the cases reported here, is either genital or extragenital. Genital causes of bleeding include vaginal trauma, uterine disease, and benign and malignant reproductive system neoplasia. 1,3–7 Extragenital origins of hemorrhage include urinary tract inflammation or injury and neoplasia, and coagulopathies.1,8 No clinical signs other than vulvar hemorrhage were seen in the cases described in this report.
Canine hemangiomas have been reported to occur in skin, oral mucosa, tongue, spinal cord, kidney, bladder, liver, and spleen.12–15 A search of the Veterinary Medical Database (VMDB) revealed two additional cases of diagnosed vaginal hemangioma in the United States. The first was a geriatric, spayed female dog that was presented with a 4-week history of vulvar hemorrhage. A vaginal mass was located on physical examination and was resected via episiotomy. The second case found during a VMDB search was a 2- to 4-year-old, spayed female dog that was presented with an unknown duration of chronic vaginitis without mention of whether hemorrhage was present. A periurethral vaginal mass was palpated, although it was not visible on preoperative vaginoscopy. An episiotomy was performed, and a small discolored area of vaginal tissue was noted and excised. To the authors’ knowledge, the cases described in the current report are the first vaginal vascular tumors of the vagina reported in the veterinary literature.
Hemangioma was the histopathological diagnosis in all four cases. Unfortunately, only one (case no. 2) was available for author review. Differential diagnoses in these cases would include angiomatosis, which can be subdivided into vascular hamartoma, vascular malformation, vascular hyperplasia, or vascular ectasis; and a well-differentiated hemangiosarcoma.16 Differentiating these types can be very difficult and in some cases impossible. In fact, vascular structures diagnosed as hemangiomas often seem to be more consistent with a vascular malformation than a true neoplasm, so, alternatively, the cases reported here could be classified as such. Vascular hamartomas in the skin are distinguished by multiple vascular structures surrounding normal preexisting dermal blood vessels. These tumors, as in hemangiomas, have morphologically normal and flattened endothelial cells. In hemangiosarcoma, the endothelial cells are plump in appearance with nuclear pleomorphism, piledup cells along the basal laminae, and mitotic figures present. 16 A well-differentiated hemangiosarcoma can be difficult to distinguish histologically from a hemangioma, vascular malformation, or other vascular neoplasms.
Conclusion
Vaginal hemangioma, vascular malformations, or neoplasms should be considered in the differential diagnosis for either intact or spayed female dogs with vaginal hemorrhage. While vaginoscopy was the diagnostic tool utilized in three cases, distinguishing the small, red, fleshy mass from clotted blood in the second case was challenging. Flushing the vagina with saline and suctioning the accumulated blood clots assisted with visualization. The small size of the mass may belie the severity of hemorrhaging that can occur. The degree of blood loss demonstrated in the second case underscores the importance of preoperative complete blood cell counts and clotting panels, along with aggressive RBC or alternative oxygen-carrying fluid support. Surgical excision, at least in case no. 2, appeared to be curative.
Foley Catheter; Cook Veterinary Products, Bloomington, IN 47403
Oxyglobin; Biopure, Cambridge, MA 02141
PDS II; Ethicon, Somerville, NJ 08876
Acknowledgments
The Veterinary Medical Database (VMDB) was utilized in this series to identify additional cases. The VMDB does not make any implicit or implied opinion on the subject of this report. DoctorsWilliam Dernell and Eric Pope are acknowledged for their contribution of cases to this series.
Citation: Journal of the American Animal Hospital Association 44, 2; 10.5326/0440086
Citation: Journal of the American Animal Hospital Association 44, 2; 10.5326/0440086
