Nasal osteosarcoma and interstitial cell tumor in a Vancouver Island marmot (Marmota vancouverensis)

A 6-yr-old male Vancouver Island marmot (Marmota vancouverensis) presented for poor hibernation, weight loss, and symmetric trunk alopecia. An abdominal interstitial cell tumor was identified and surgically removed. Serum levels of estrogen were markedly elevated before surgery and decreased after tumor removal, indicating that the tumor had been functionally secretory. Nine months later, the marmot presented with respiratory stridor. A large boney nasal mass was identified radiographically and evaluated by computed tomography (CT) prior to surgical debulking. The marmot did not recover from anesthesia. Pathologic findings included a nasal osteosarcoma with lysis of the cribriform plate, and endocardial fibrosis with degenerative changes within the adjoining myocardium. This is the first known report of nasal osteosarcoma and interstitial tumor in a Vancouver Island marmot.     

Probable paraneoplastic leukocytosis in a dog with a gastrointestinal stromal tumor

A 9-year-old female spayed Boston Terrier presented for diagnostic investigation of lethargy, poor appetite, weight loss, and a marked leukocytosis. Significant muscle wasting and a palpable abdominal mass were present on physical examination. Abdominal imaging revealed the mass to be of small intestinal origin; consequently, an intestinal resection and anastomosis were performed without complication. The histopathologic diagnosis was a gastrointestinal stromal tumor, verified by immunohistochemical positivity to CD117 (KIT). Two weeks after discharge, the leukocytosis had resolved. Though the exact molecular mediator of the severe leukocytosis was undetermined, resolution following tumor removal suggests a paraneoplastic cause. To the authors' knowledge, this is the first reported case of probable paraneoplastic leukocytosis secondary to a gastrointestinal stromal tumor in the dog. Gastrointestinal tract imaging should be performed when this uncommon hematologic abnormality is present.     

Small-colon rupture attributable to granulosa cell tumor in a mare

A large granulosa cell tumor was believed to be responsible for causing obstruction and subsequent rupture of the small colon in a 10-year-old Quarter Horse mare. Two months earlier, a mass, tentatively diagnosed as granulosa cell tumor of the left ovary, had been identified by means of rectal palpation and ultrasonography. The mare was evaluated for clinical signs of acute, severe, abdominal pain, increased heart rate, cyanotic mucous membranes, clinical dehydration, with high PCV, leukopenia, and extreme abdominal distension. A large soft tissue mass and taut band that constricted the lumen of the small colon were palpable per rectum. Septic peritonitis was diagnosed on the basis of results of abdominocentesis. Exploratory surgery revealed extensive fecal contamination of the abdominal viscera, and the mare was euthanatized because of the resultant poor prognosis. At necropsy, the small colon was occluded by a taut, left broad ligament and the ovarian mass that was proved to be a granulosa cell tumor. The occlusion had caused impaction of the small colon, with subsequent perforation at the level of the broad ligament.     

Laparoscopic Removal of a Large Abdominal Testicular Teratoma in a Standing Horse

Objective— To describe laparoscopic removal of a large testicular teratoma in a standing horse.
Study Design— Clinical report.
Animals— Thoroughbred horse (11 months) with a testicular teratoma.
Methods— A unilateral cryptorchid testicle could not be removed by an inguinal approach under general anesthesia because of it s large size. After recovery from general anesthesia, ultrasound evaluation revealed a 24 × 19 cm fluid-filled testicular mass. The mass was removed by paralumbar fossa laparoscopy with the horse in a standing position. After fluid aspiration of the mass, the mesorchium and ductus deferens were ligated with extracorporeal knots and the mass retrieved inside a laparoscopic specimen pouch. Morphologic features were consistent with a teratoma.
Results— Laparoscopic-guided aspiration of fluid from the teratoma decreased mass size and increased ease of manipulation and retrieval. Retrieval of the teratoma in a laparoscopic specimen pouch prevented loss of abdominal insufflation, helped reduce fluid leakage, and potential seeding of neoplastic cells.
Conclusion— Use of laparoscopy for removal of neoplastic cryptorchid testicles offers many advantages including minimal invasiveness and increased safety associated with good visibility of structures.
Clinical Relevance— Standing laparoscopic surgery should be considered for removal of testicular neoplasms in horses.     

Huge myxosarcoma arising from the greater omentum in a dog

A 13-year-old intact Pomeranian bitch presented with a 2-month history of abdominal distension and anorexia. Ultrasonography and computed tomography revealed a large tumor in the abdominal cavity without metastases. The tumor was surgically resected and histopathologically characterized by spindle-shaped to atypical-shaped neoplastic cells with basophilic stroma in the omental adipose tissue. Immunohistochemistry revealed that the neoplastic cells were positive for vimentin but negative for cytokeratin, S-100 protein, and α-SMA. The bitch was diagnosed as a myxosarcoma arising from the greater omentum. Postoperatively, metronomic chemotherapy with cyclophosphamide and piroxicam was initiated. The tumor recurred on postoperative day 49. Although the bitch died 102 days after the initial examination, her general condition was maintained until death.     

Prostatic carcinoma causing urethral obstruction and obstipation in a cat

A 9-year-old intact male cat was presented for vomiting and straining to defecate. A large abdominal mass was palpated. The urinary bladder was full and non-expressible. Exploratory laparotomy revealed that the mass was compressing the colon and encircling the urethra caudal to the bladder. The mass was removed, the urethra transected, and the urinary bladder marsupialized to the ventral abdominal wall to allow urine drainage. Histopathologic examination of the mass revealed a prostatic carcinoma. The cat died approximately 6 weeks after removal of the mass. This is the first reported case of a prostatic carcinoma causing urethral obstruction and obstipation in a cat.     

Bypass Surgery for the Treatment of Small Intestinal Ileus in the Horse A Report of Three Cases

The medical management of three horses with simple and strangulating small intestinal obstructions was unsuccessful and was therefore supported by surgical bypasses. Jejunocecostomies were used to treat horses with postoperative paralytic ileus that was unresponsive to medical management. These horses had abdominal pain, gastric distention, heart rate elevations greater than 60/minute, and small intestinal distention on rectal palpation. Two horses experienced weight loss which responded to bypass removal. The bypass effectively decreased the need for intravenous fluid administration and repeated nasogastric intubation.     

Laparoscopic Adhesiolysis in a Horse

Objective —The purpose of this report was to describe the use of laparoscopy as a method of treatment for abdominal adhesions in the horse.
Clinical Report —Unilateral ovariectomy for removal of a granulosa cell tumor was performed through a diagonal paramedian approach in a 14-year-old Arabian mare. Progressive incisional swelling and hemorrhage culminated in acute incisional dehiscence with herniation of ileum on the sixth postoperative day. Septic peritonitis that responded to parenteral antibiotic therapy was identified 7 days after hernia repair. Seven days later, the mare had signs of abdominal pain, and adhesions of small intestine to the paramedian incision were identified on rectal palpation. Transrectally assisted laparoscopic adhesiolysis was performed. No further complications occurred.
Clinical Relevance —Laparoscopic adhesiolysis may provide better observation of adhesions and reduced postoperative morbidity compared with laparotomy.     

Hemoperitoneum caused by rupture of a juvenile granulosa cell tumor in an equine neonate

A neonatal foal was examined because of apparent abdominal pain and distention, anemia, and hemoperitoneum. Exploratory laparotomy was performed, and a large spherical mass, which had ruptured, was found in the area of the left ovary. Left salpingo-oophorectomy was performed. The mass was determined to be a juvenile granulosa cell tumor.     

Unusual presentation of splenic myelolipoma in a dog

A 13-year-old dog was presented with clinical signs of anemia, vomiting, weight loss, and progressive abdominal distension. Abdominal ultrasonography and radiography revealed a large mass, which was removed surgically. Cytologic and histologic evaluation of the mass revealed a mixture of fat and hematopoietic tissue, consistent with a splenic myelolipoma.     

Malignant granulosa-theca cell tumor in a two-year-old Miniature Horse.

A 2-year-old female Miniature Horse that presented with a history of progressive weight loss, depression, and diarrhea was diagnosed at necropsy with a highly malignant abdominal neoplasm involving the left ovary, kidneys, adrenal glands, intestines, and various abdominal and thoracic lymph nodes. Microscopic examination of these masses revealed large pleomorphic cells that stained positive for vimentin and inhibin and negative for epithelial membrane antigen and placental alkaline phosphatase. Ultrastructural examination of the cells revealed a high nucleocytoplasmic ratio and indented euchromatic nuclei with large nucleoli. Based on the gross, microscopic, immunohistochemical, and ultrastructural features, the neoplasm was identified as a malignant granulosa-theca cell tumor, a rare neoplasm in young horses.     

Clinical course of renal adenocarcinoma associated with hypercupraemia in a horse

A four-year-old shire mare with haematuria, colic, terminal weight loss and an abdominal mass had a large unilateral renal adenocarcinoma. Clinical signs were monitored for 11 months. Increased serum copper concentrations were measured on two occasions. Hypercupraemia is discussed as a possible paraneoplastic change.     

Resection of a Large Intra‐Abdominal Tumor in the Mexican Axolotl: A Case Report

Objective— This case report describes the surgical removal of an intra‐abdominal tumor from a Mexican axolotl (Ambystoma mexicanum). The animal was admitted with left abdominal swelling that had increased over 4 months. Methods— Surgical removal was performed under general anesthesia with MS222 under an operating microscope. Exploratory laparotomy was performed through 2.5 dorsocranial skin incision in the left flank, followed by subcutaneous dissection. Results— The tumor involved the spleen, was adjacent to the descending colon, and supplied by vessels from the spleen, stomach, and colon. The mass was removed by clamping and transecting the spleen and the peritoneum was closed with a continuous suture pattern, while abdominal muscles and skin were closed in layers. After a total duration time of anesthesia of 90 minutes the animal was kept in prophylactic antibiotic baths. Tissue sections revealed characteristics of both lymphangiosarcoma and lymphosarcoma with an appearance typical for a malignant tumor. Conclusions— Abdominal surgery was performed in an axolotl and the surgical wound healed without complication.     

Testicular neoplasia in the retained testicles of an intersex male dog

This case describes the presentation and management of an 8 yr old phenotypically female intersex male dog presented for evaluation of a mass in the right inguinal region. The right inguinal space was surgically explored, and a large irregular mass resembling a fully developed testicle was identified in the right vaginal tunic. A second mass resembling an atrophied, but anatomically mature testicle, was identified in the left tunic. The larger mass was identified as a Sertoli cell tumor that had replaced all normal testicular tissue. The smaller mass was identified as a testicle that contained a small intratubular seminoma. The patient was diagnosed as having a phenotypic female sex, chromosomal male sex, and a gonadal male sex. Hormone assays completed before and after the gonadectomy and mass removal document an elevation of circulating progesterone presurgically that returned to baseline by 1 mo postsurgically. The source of the progesterone was identified to be the Leydig cells of the atrophied testicle.     

Small intestinal pseudodiverticulosis in a pony mare

A 14-y-old pony mare was referred after 30-d duration of intermittent pyrexia, anorexia, weight loss, and change in manure consistency. Physical examination revealed a palpable but reducible ventral abdominal mass. Transabdominal ultrasonography revealed multiple distended, hypomotile, and thickened small intestinal loops in close approximation with numerous, well-defined, hyperechoic masses. There was a large amount of echogenic peritoneal fluid; abdominocentesis revealed a neutrophilic and macrophagic inflammatory exudate, and a mixed bacterial population was cultured. Given the poor prognosis, the mare was euthanized. The autopsy findings included a large abdominal abscess, serosanguineous peritoneal fluid with fibrin strands, and ~50 outpouches communicating with the lumen and extending from the anti-mesenteric aspect of the duodenum, jejunum, and ileum. These structures were classified as pseudodiverticula based on the histologic absence of the tunica muscularis layer of the intestinal wall. Pseudodiverticula should be included as a differential etiology in horses when clinical signs consistent with colic, diarrhea, or weight loss are recognized and, when on examination, one or more organized masses are palpated or visualized on transabdominal ultrasound, as well as visualization of small intestinal loops with thickened walls.     

Renal Cystic Adenocarcinoma in a Flowerhorn Cichlid with Metastatic Involvement of the Spleen

Abstract

A 480-g flowerhorn cichlid (an ornamental hybrid) with severe bilateral abdominal swelling, bulla-like structures on the skin, bilateral exophthalmia, and a prolapsed intestine was presented. Radiographs showed compression of the posterior part of the swim bladder and abdominal distention. Ultrasonography of visceral organs revealed a heterogeneous mass with hypoechoic to anechoic polycystic parenchyma and free fluid in the abdominal cavity. At necropsy, free fluid in the abdominal cavity and a large polycystic mass originating from the posterior kidney were observed. Histologically, the mass was composed of more cystic growth of tubules. The renal architecture was replaced by tubules, often irregular in shape, lined by simple to lightly stratified layers of neoplastic and pleomorphic cuboidal to columnar epithelial cells and the absence of glomeruli. Birefringent crystals were observed with polarized light within the lumen of some tubules. The apical border of the neoplastic cells was periodic acid–Schiff positive. Immunohistochemically, the neoplastic cells were positive for cytokeratin AE1/AE3 and proliferating cell nuclear antigen and were negative for p53 (tumor suppressor protein). Microscopic metastasis was seen in the spleen. The metastatic tumor was classified as a cystic adenocarcinoma of the kidney, originating from the proximal tubules.

Received October 7, 2016; accepted June 18, 2017 Published online July 31, 2017     

Use of intraoperative impression smear cytology to guide successful treatment of a large renal cyst in a dog: a case report

A 13-yr-old Shih tzu was referred for surgical management of right-sided cranial abdominal mass, which corresponded to large, cavitated renal mass on ultrasonography, and was suspected to represent neoplasia. Intraoperative impression smear cytology (ISC) of the renal mass wall was consistent with benign renal cyst (RC), without evidence of neoplasia or infection. Deroofing and omentalisation were performed and histopathology was consistent with benign RC. Chronic kidney disease was diagnosed 4 mon postoperatively, however, the dog was asymptomatic, without cyst reoccurrence. Intraoperative ISC is an expedient and inexpensive diagnostic technique that can guide most appropriate treatment in dogs with large RCs.     

PARACLOACAL GLAND CARCINOMA IN A SUGAR GLIDER (PETAURUS BREVICEPS)

A male sugar glider (Petaurus breviceps) was presented to the National Taiwan University Veterinary hospital for repeated self-mutilation of the cloacal region. After correction of husbandry deficiencies and medical management of the lesion, the condition improved but a pericloacal mass was found. Surgical removal of the mass resolved the self-mutilation, and a dorsal paracloacal gland carcinoma was diagnosed on histopathological examination. Straining to defecate and a pericloacal mass could indicate neoplasia in sugar gliders. A tumor should be differentiated from chronic inflammation, infection, paracloacal gland impaction, and hyperplasia. Surgical removal is recommended as a treatment for paracloacal gland carcinoma in sugar gliders. Further monitoring is suggested after surgical removal of the tumor.     

Malignant pheochromocytoma presenting as a bradyarrhythmia in a dog

Objective: To describe a case of atrioventricular block and syncope secondary to systemic hypertension in a dog with malignant pheochromocytoma. Case Summary: A 13‐year‐old spayed female mixed‐breed dog presented following an acute onset of collapse. The dog was hypertensive and had paradoxical high‐grade second‐degree atrioventricular block with concurrent syncope. Initial emergent therapy included a nitroprusside infusion for the systemic hypertension and vagolytic therapy for the bradyarrhythmia. A left adrenal mass was seen on abdominal ultrasound and was further characterized by MRI. Following medical stabilization with phenoxybenzamine and propantheline, a left adrenalectomy was performed. Histological diagnosis was consistent with a malignant pheochromocytoma. Following tumor removal there has been no further hypertension, atrioventricular block or syncope. Unique information provided: This is the first documented case of a malignant pheochromocytoma presenting as syncope secondary to hypertension induced atrioventricular block.     

Sclerosing Encapsulating Peritonitis in Four Dogs and a Cat

Sclerosing encapsulating peritonitis (SEP) was diagnosed in four dogs and one cat. Clinical signs included vomiting, abdominal pain, palpable abdominal mass, and ascites. The abdominal fluid was red-tinged and contained large numbers of red blood cells, macrophages, mixed inflammatory cells, reactive mesothelial cells, and fibroblasts. At surgery, the typical appearance was of multiple surfaces covered with granulation tissue or fibrous tissue or both. Multiple adhesions were often present. Causes of SEP included steatitis, fiberglass ingestion, and bacterial infection. Treatment included administration of antibiotic, corticosteroid, and diuretic medications. The major long-term management problems were chronic weight loss, ascites, and progression of concurrent disease.