Ultrasound-guided biopsy as a diagnostic aid in three horses with a cranial mediastinal lymphosarcoma

An ultrasound examination of the thorax of three horses which were performing poorly or had mild signs of colic showed that they had a cranial mediastinal mass and a pleural effusion. A cytological examination of the pleural fluid showed that it did not contain neoplastic cells. A histological examination of an ultrasound-guided core biopsy of the cranial mediastinal mass showed that in each of the three horses it was a lymphosarcoma.     

Diagnosis of an Abdominal Splenosis in a Case of Ambulatory Paraparesis of the Hind Limbs in a Ferret (Mustela putorius furo)

A 2-year-old spayed female ferret (Mustela putorius furo) was presented with a 2-day history of ambulatory paraparesis of the hind limbs. On physical examination a mass was palpated in the cranial abdominal region, caudal to the stomach. A complete blood cell count revealed a normocytic normochromic anemia and reactive lymphocytes. A hypoechoic abdominal mass was observed during an ultrasound examination of the abdomen. An exploratory laparotomy was recommended and performed during which a pyramidal mass resembling a lobe of fatty liver tissue, plus omental torsion, was removed. The histopathologic diagnosis of the surgically removed mass was splenosis. The abdominal pain and ambulatory paraparesis resolved after surgery, which suggests that the paraparesis was due to pain. The findings in this report indicate that splenosis should be included as a differential diagnosis when a ferret presents with an abdominal mass and acute abdominal pain.     

Subclinical intestinal duplication in a cat

An abdominal mass was identified upon palpation of the abdomen in a normal, asymptomatic, 1-year-old female domestic shorthair cat presented for elective ovariohysterectomy. Radiographic and ultrasound examinations demonstrated a well-circumscribed caudal abdominal mass. Ultrasound guided needle aspiration cytology was consistent with an accumulation of squamous epithelial cells. The mass was associated with the jejunum and was excised via resection anastomosis of the intestinal segment after ovariohysterectomy. Histologic examination provided the diagnosis of an intestinal duplication lined with epithelium typical of that in the esophagus. The cat recovered without complications.     

Congenital mesoblastic nephroma in a young basset hound dog

An 18‐month‐old male basset hound was presented with vomiting, diarrhoea and depression. Abdominal ultrasonography revealed a mass in the left kidney. An ultrasound‐guided core‐biopsy indicated aggregates of spindle cells, but did not allow a definitive diagnosis. Nephrectomy was performed after a period of six months, when ultrasound examination revealed a slight increase in mass dimensions. Histologically the mass was composed of neoplastic spindle cells forming interlacing fascicles, bundles and whorls, within a loose myxoid to dense collagenous stroma. Immunohistochemically neoplastic cells were positive for vimentin and smooth muscle actin. Based on these findings the tumour was diagnosed as a congenital mesoblastic nephroma, classical variant. After a two‐and‐a‐half‐year follow‐up the dog was clinically healthy, indicating a benign behaviour. To the authors’ knowledge, this report describes the first case of canine congenital mesoblastic nephroma successfully treated surgically, with a reasonable postsurgical follow‐up.     

PARAESOPHAGEAL CYST IN A HORSE

A 2 year old Morgan gelding was evaluated for a non-painful mass located caudodorsal to the larynx. Radiographically, the mass was ovoid shaped and had a peripheral rim of mineralization. Slight ventral displacement of the dorsal margin of the trachea could also be identified. Uniform moderate level echoes were seen throughout the interior of the mass on ultrasound examination. An esophagram was performed and demonstrated displacement without involvement of the esophagus by the mass. The esophagus appeared as a separate structure from the mass on both the ultrasound examination and esophagram. During surgical removal, the mass also appeared as a distinct structure from the esophagus. Histologically, the mass was consistent with an epithelial inclusion cyst which originated from the esophagus.     

Pancreatic cyst in a cat

CASE HISTORY: A 5-year-old neutered male Cornish Rex cat was presented for evaluation with a history of vomiting over the previous 5 days. CLINICAL FINDINGS: An abdominal mass was palpated, which was shown to be cystic by ultrasound examination. Exploratory surgery revealed this to be associated with the pancreas and it was duly resected. Histopathology was performed on the cystic mass. DIAGNOSIS: Pancreatic cyst with associated chronic active inflammation. CLINICAL RELEVANCE: This is the first report of a true pancreatic cyst in a cat.     

Retroperitoneal Abscess Associated With a Migrating Grass Awn in a Cat: Treatment With Omentalization and Grass Awn Removal

An 18-month-old domestic short hair male castrated cat presented with a history of fever of unknown origin of 1-year duration. Abdominal ultrasound revealed a mixed echogenicity mass. Cytological examination of the fluid obtained through fine needle aspiration was consistent with a retroperitoneal abscess. The cat underwent a midline celiotomy and the abscess was opened, lavaged, and omentalized. Antibiotics were also administered. Two months after surgery, the cat represented with a fluctuant swelling in the right flank region at the lumbodorsal triangle. Abdominal and mass ultrasound showed a mixed echogenicity swelling in the right flank. Under gas anesthesia, the swelling was surgically explored and a 0.4 cm long grass awn was found and removed. Telephone communication with the owners 6 months after surgery found the cat to be free of clinical signs.     

Pancreatic cyst in a cat

CASE HISTORY: A 5-year-old neutered male Cornish Rex cat was presented for evaluation with a history of vomiting over the previous 5 days.

CLINICAL FINDINGS: An abdominal mass was palpated, which was shown to be cystic by ultrasound examination. Exploratory surgery revealed this to be associated with the pancreas and it was duly resected. Histopathology was performed on the cystic mass.

DIAGNOSIS: Pancreatic cyst with associated chronic active infl ammation.

CLINICAL RELEVANCE: This is the first report of a true pancreatic cyst in a cat.     

Magnetic resonance imaging features of an extranodal T cell rich B cell lymphoma in the pharyngeal mucosa in a horse

An 11‐year‐old Warmblood gelding was presented for inspiratory stridor and dysphagia. Based on history and clinical examination, a solitary mass localised in the oropharynx was suspected. Due to its inaccessibility and defensive behaviour of the horse, it was difficult to visualise this mass either by upper airway endoscopy or by oral examination and the conventional imaging methods (radiology and ultrasound) provided only limited information. Fine needle aspiration cytology was suggestive of lymphoma, but the exact localisation and the extent of tissue infiltration of the tumour could only be defined by magnetic resonance imaging (MRI). MRI has proved to be a very useful diagnostic tool in equine lameness investigation and, as this case illustrates, it has considerable diagnostic potential for soft tissue examination of the equine head.     

Fibrosarcoma arising at the site of a retained surgical sponge in a cat

Abstract: An 8‐year‐old female spayed domestic shorthair cat had an abdominal mass palpated as an incidental finding on physical examination. Cytologic findings in ultrasound‐guided fine‐needle aspirates of the mass were most compatible with a sarcoma, with abundant mineralized material and mixed inflammation. The mass was removed surgically and on gross examination was white‐tan, firm, associated with the mesentery, and when transected contained a gauze sponge in its center. On histopathologic examination, an area of central necrosis with mineralization and numerous refractile fibers consistent with sponge material was surrounded by dense fibrous connective tissue (gossypiboma). Within the connective tissue was a population of highly pleomorphic spindle cells consistent with a fibrosarcoma. Immunohistochemically, most neoplastic cells stained strongly positive for vimentin and a low number of cells were positive for smooth muscle actin. The results were consistent with a fibrosarcoma arising at the site of a retained surgical sponge. At a follow‐up visit 2 months postoperatively, ultrasonographic and cytologic evidence of metastasis was found in the spleen and mesentery. To our knowledge, this is the first report of malignant transformation at the site of a retained surgical sponge in a cat and the first report of a fibrosarcoma arising within a gossypiboma in a domestic animal.     

Osteosarcoma of the proximal radius in a donkey

A mature donkey was presented for evaluation of a forelimb lameness and presence of a large mass on the left forelimb distal to the elbow joint. Clinical examination, radiographs and cytological examination of ultrasound‐guided fine needle aspirates of the mass led to a presumptive diagnosis of osteosarcoma. The donkey was subsequently subjected to euthanasia. Post mortem examination confirmed the diagnosis of osteosarcoma in the proximal radius with expansion of the mass through the ulnar cortex and metastases to liver and regional lymph nodes, areas of metastasis previously unreported in the equine literature.     

Surgical Treatment of an Abdominal Abscess Caused by a Migrating Iron Wire From the Ventral Colon,a Case Report

A 13-year-old mare presented for evaluation of recurrent colic episodes. The horse was diagnosed with a mass within the spleen at the ultrasound examination of the abdomen; the levels of Serum Amyloid A and the fibrinogen were high and so a presumptive diagnosis of an abscess involving the spleen was made base on clinical, ultrasonographic and laboratory findings and it was decided to perform n exploratory laparotomy for a definitive diagnosis and possible treatment. Upon abdominal exploration a mass involving the spleen, the lateral wall of the ventral colon adherent to the left abdominal wall was diagnosed and with an intraoperative ultrasound examination a linear hyperechoic foreign body was diagnosed within the mass. It was removed through an enterotomy of the left ventral colon that allowed the digital exploration of the mass without spilling of pus within the peritoneal cavity. The horse was discharged and the long term follow-up revealed no complications and no more signs of abdominal pain.     

Conjunctival dacryops in a domestic shorthair cat

A 1-year-old spayed female domestic shorthair cat with a 1-week history of a conjunctival mass located in the dorsolateral quadrant of the right eye was presented to a referral hospital. Ophthalmic examination revealed a pink, fluctuant, and non-painful cystic swelling of the upper right palpebral conjunctiva. An ocular ultrasound confirmed the presence of a fluid-filled cystic structure that extended into the temporal orbit. The histopathology of the excisional biopsy revealed multiple cysts lined by ductal epithelium along with dilated lacrimal gland ducts and lymphocytic nodules adjacent to the dorsal lacrimal gland; consistent with a diagnosis of dacryops.     

IATROGENIC BILOMA (BILIARY PSEUDOCYST) IN A CAT WITH HEPATIC LIPIDOSIS

An eight-year-old neutered female domestic longhair cat was presented with icterus and a palpable cranial abdominal mass. The cat had undergone an open biopsy of the liver two years previously. Abdominal radiographic findings included a solitary soft tissue mass originating from the right cranial hepatic region. An anechoic cystic structure was identified on ultrasound examination. Surgical exploration revealed the cyst to be filled with bile. The fibrous capsule of the cyst originated in the liver. Severe hepatic lipidosis was also present. It is believed that the bilorna was a complication of the previous hepatic biopsy and not a sequela of hepatic lipidosis.     

Caudal mediastinal thyroglossal duct cyst in a cat

An eight-year-old domestic shorthair cat was evaluated because of dyspnoea secondary to pleural effusion. Ultrasound examination identified a large anechoic cyst-like structure in the caudal thorax. A median sternotomy was performed, and the cystic mass was removed. Microscopically, the excised tissue was identified as a multilocular thyroglossal duct cyst with ectopic thyroid tissue. To the authors' knowledge, this is the first report of a mediastinal thyroglossal duct cyst in a cat. Despite the rarity of this lesion, it should be considered when a cystic thoracic structure is identified on thoracic ultrasound. Surgical excision of the cyst resulted in complete resolution of the pleural effusion and clinical signs.     

Prostatic sarcomatoid carcinoma in a dog: cytologic and immunohistochemical findings

An 8-year-old neutered male Boxer was presented with tenesmus, hemorrhagic urethral discharge, and dysuria. Abdominal ultrasound and radiographic examinations revealed irregular prostatic enlargement. Laparotomy was performed and intraoperative cytology was done on imprint smears of a biopsy specimen obtained from a prostatic mass. The cytologic preparation was highly cellular and contained a predominant population of atypical, large, loosely cohesive spindle cells, with rare multinucleated cells and mitotic figures. The cytologic findings were consistent with undifferentiated sarcoma. At necropsy, a large cystic prostatic mass and numerous satellite nodules in the soft tissues around the pelvis were found. On histologic examination the tumor was composed primarily of bundles of neoplastic spindle cells. Rare pseudo-acinar structures and signet-ring cells also were observed. On immunohistochemical examination, the neoplastic cells co-expressed cytokeratin and vimentin. Based on histologic and immunohistochemical findings, the tumor was diagnosed as primary prostatic sarcomatoid carcinoma. This is a rare tumor in dogs, in which biphasic morphology of epithelial and mesenchymal cells can complicate the diagnosis, requiring immunochemical stains for confirmation.     

SURGICAL MANAGEMENT OF PANCREATIC NODULAR HYPERPLASIA BY PARTIAL PANCREATECTOMY IN A BLACK-TAILED PRAIRIE DOG (CYNOMYS LUDOVICIANUS)

A 7.5-year-old male black-tailed prairie dog was presented for diarrhea of 3 weeks’ duration. Clinical examination revealed a multinodular mass in the left cranial quadrant of the abdomen that was confirmed with ultrasound. An exploratory laparotomy was performed and the majority of the mass and adherent spleen were removed. Histological diagnosis was severe pancreatic nodular hyperplasia associated with secondary pancreatitis and passive splenic congestion. The prairie dog recovered without complications. Three weeks following the surgical procedure, follow-up ultrasound showed no evidence of abnormal tissue in the pancreaticoduodenal area. Two months postsurgery, a follow-up computed tomographic scan revealed no significant abnormalities. No recurrence was noted 13 months following the mass removal. This article describes the diagnosis of pancreatic nodular hyperplasia in a prairie dog and successful treatment of complications arising from the condition by partial pancreatectomy.     

Osseous metaplasia within a canine insulinoma

An 11‐year‐old male castrated mixed‐breed dog was presented for exercise intolerance, tetraparesis, and persistent hypoglycemia. Abdominal ultrasound examination revealed 2 nodules within the right limb of the pancreas. Cytology from one nodule was consistent with a carcinoma of neuroendocrine origin, with a primary differential diagnosis of insulinoma. Histologic evaluation and immunohistochemistry for synaptophysin and insulin confirmed the diagnosis of insulinoma. Additionally, there was a solitary nodule of mineralized compact bone composing approximately 60% of the mass. To the authors' knowledge, this is the first report of osseous metaplasia within an insulinoma (islet cell carcinoma).     

Laparoscopic Cystotomy for Removal of a Large Bladder Polyp in a Juvenile Alpaca with Polypoid Cystitis

Objective: To describe a method for laparoscopic cystotomy in an alpaca. Study Design: Case report. Animals: Female alpaca. Methods: An 8‐month‐old female alpaca was admitted with a 6‐week history of straining to urinate and vulvar swelling. Transrectal ultrasound examination revealed a 1.5 × 1.5 × 2 cm polyp within the bladder. Results: The mass was excised using laparoscopic cystotomy. Leakage from the cystotomy site resolved over 12 days using a Foley catheter. The alpaca was healthy and urinating normally at 9 months after surgery. Conclusion: Minimally invasive surgery by laparoscopic cystotomy can be used to remove large urinary polyps in alpacas. Clinical Relevance: Urinary bladder polyps should be considered as differential diagnosis in alpacas with stranguria.     

Chronic prostatitis, cystitis, pyelonephritis, and balanoposthitis in a cat

An adult, intact male domestic shorthair presented for preputial swelling and urinary incontinence. A caudal abdominal mass was palpated. A transabdominal ultrasound examination showed severe prostatomegaly with abnormal tissue extending along the urethra. The cat was euthanized due to the owner's financial constraints and the veterinarians' suspicion of a poor long-term prognosis. Biopsies showed chronic active inflammation of the prostate, bladder, kidneys, ureters, penis, and prepuce most consistent with a chronic infectious process. Reports of feline prostatic disease of any kind are rare. Chronic prostatitis may have a more favorable prognosis than feline prostatic adenocarcinoma, currently the most commonly reported disease of the feline prostate.