Ureteral mast cell tumor in a dog

Ultrasonographic diagnosis of a lymphomatous lymph node presumptively infiltrating the ureter causing hydronephrosis in a 3-year-old dog

A 3-year-old male neutered mixed breed dog was presented for chronic vomiting and diarrhea. Abdominal ultrasound revealed a large amorphous, heterogeneous mass within the left mid to caudal abdomen most consistent with medial iliac lymph node. It appeared to invade the left ureter and extend distally causing ureteral obstruction and hydronephrosis. Concurrent additional ultrasound findings were consistent with metastatic or multicentric neoplasia. Fine needle aspirates of the lymph node and spleen both confirmed large cell lymphoma. These findings present evidence of lymphoma invading directly from an organ into the ureter which has not previously been reported in dogs.

Proposed Diagnostic Criteria and Classification of Canine Mast Cell Neoplasms: A Consensus Proposal

Mast cell neoplasms are one of the most frequently diagnosed malignancies in dogs. The clinical picture, course, and prognosis vary substantially among patients, depending on the anatomic site, grade and stage of the disease. The most frequently involved organ is the skin, followed by hematopoietic organs (lymph nodes, spleen, liver, and bone marrow) and mucosal sites of the oral cavity and the gastrointestinal tract. In cutaneous mast cell tumors, several grading and staging systems have been introduced. However, no comprehensive classification and no widely accepted diagnostic criteria have been proposed to date. To address these open issues and points we organized a Working Conference on canine mast cell neoplasms in Vienna in 2019. The outcomes of this meeting are summarized in this article. The proposed classification includes cutaneous mast cell tumors and their sub-variants defined by grading- and staging results, mucosal mast cell tumors, extracutaneous/extramucosal mast cell tumors without skin involvement, and mast cell leukemia (MCL). For each of these entities, diagnostic criteria are proposed. Moreover, we have refined grading and staging criteria for mast cell neoplasms in dogs based on consensus discussion. The criteria and classification proposed in this article should greatly facilitate diagnostic evaluation and prognostication in dogs with mast cell neoplasms and should thereby support management of these patients in daily practice and the conduct of clinical trials.

Primary Ureteral Hemangiosarcoma in a dog

BACKGROUND

Primary ureteral neoplasia in dogs is extremely rare. To the best of the authors' knowledge, this is the second documented case of a primary ureteral hemangiosarcoma. This case report describes the clinical and pathological findings of a primary distal ureteral hemangiosarcoma.

CASE PRESENTATION

A 12-year-old spayed female goldendoodle was presented with a history of polyuria and weight loss. Abdominal radiographs revealed a large cranial abdominal mass. Abdominal ultrasound and computed tomography (CT) identified a left sided distal ureteral mass with secondary hydroureter and a left lateral hepatic mass with no evidence of connection or diffuse metastasis. A left ureteronephrectomy, partial cystectomy, and left lateral liver lobectomy were performed. Histopathology was consistent with primary ureteral hemangiosarcoma and a hepatocellular carcinoma. Adjunctive therapy including chemotherapy was discussed but declined.

CONCLUSION

Due to its rarity, the authors of this case presentation believe that ureteral hemangiosarcoma should be included as a differential diagnosis when evaluating a ureteral mass. With the unknown, and suspected poor prognosis, routine monitoring with adjunctive therapy should be considered.

Primary ureteral leiomyosarcoma in a dog

CASE DESCRIPTION

A nearly 6-year-old female spayed Labrador Retriever was presented for acute abdominal pain and lethargy. The dog had no previous health concerns apart from occasional episodes of urinary incontinence in the 2 months prior to presentation. A retroperitoneal mass involving the right ureter was found during the investigations. Serum urea was mildly elevated, but the serum creatinine was within the normal range. No distant metastases were detected. A right ureteronephrectomy was performed. The ureteral mass was confirmed as a leiomyosarcoma and completely excised. The kidney was histologically normal. Unfortunately, during a routine 3-month postoperative assessment, a recurrent mass at the previous retroperitoneal surgical site was confirmed by biopsy to be a leiomyosarcoma. Courses of doxorubicin and chlorambucil were given, but failed to halt the progression of the recurrent mass. The dog was euthanised 5.5 months postoperatively because of poor quality of life.

CLINICAL RELEVANCE

Ureteral leiomyosarcoma should be on the differential diagnosis list for a retroperitoneal mass, possibly causing severe abdominal pain with minor clinical signs associated with the urinary tract. This dog in this reported case of ureteral leiomyosarcoma had a short survival time, despite complete surgical excision and chemotherapy, because of local recurrence.

Suture-Free Ureterovesical Anastomosis Using a Microvascular Anastomosis System: Canine Cadaveric Study

OBJECTIVE

To describe a suture-free ureterovesical anastomosis using a microvascular anastomotic system (MAS) and compare the surgical time and bursting pressure to a sutured ureterovesical anastomosis (SA) with and without an extravesical seromuscular tunnel (EVSMT).

STUDY DESIGN

Randomized, unblocked design, ex vivo study.

ANIMALS

Three canine cadavers.

METHODS

For each cadaver, the ureters were sectioned into 3 equal lengths. The 6 sections were randomly assigned to receive either the MAS or end-side SA. The first cadaver (3 MAS, 3 SA) was used to refine the technique, and the remaining 2 cadavers were used for evaluation. Surgical time and bursting pressure of the anastomosis were compared between MAS and SA (n = 6 per technique). After bursting pressure testing of each anastomosis, an SMT was created over the anastomoses. Bursting pressures were again recorded and compared across techniques.

RESULTS

The surgery time was significantly shorter for MAS (median 5.4 minutes) than SA (median 15.8 minutes; P = .002). The bursting pressure was significantly higher for MAS (median 189.5 cmH2 O) than SA (median 64 cmH2 O; P = .002). The bursting pressure for MAS-EVSMT (median 398.5 cmH2 O) was not significantly different from the SA-EVSMT (median 321 cmH2 O, P = .567); however, the creation of an SMT significantly increased the bursting pressure for both techniques (P = .028, respectively).

CONCLUSION

This study demonstrated the feasibility of a suture-free ureterovesical anastomosis in the canine cadaver using a commercially available MAS. The MAS anastomosis was faster and resulted in higher bursting pressures than SA. The creation of an SMT improved the bursting resistance of both techniques but there was no difference between the techniques covered by an EVSMT.

Suture-free technique for canine ureteral resection-anastomosis using a microvascular anastomotic system: a cadaveric study

OBJECTIVE

To describe a suture-free technique for canine ureteral resection-anastomosis using a microvascular anastomotic system (MAS) and to compare surgical time and burst pressure of hand-sewn (HS) ureteral end-to-end anastomosis with the MAS technique.

STUDY DESIGN

Experimental ex vivo study.

ANIMALS

Canine cadavers (n = 8).

METHODS

For each cadaver, 1 ureter was randomly assigned to undergo HS anastomosis and the contralateral ureter had MAS anastomosis. The first 3 cadavers (6 ureters) were used to refine the MAS technique. In the other 5 dogs, surgical time and ureteral burst pressure were compared between groups (n = 5 ureters/group).

RESULTS

Preliminary procedures showed that selective impaling of the mucosa and submucosa (without muscularis and adventitia) is necessary to allow complete mechanical interlock of the anastomotic rings for the MAS technique. Median anastomotic time was significantly shorter for MAS (7.6 min) than HS (16.6 min; p = .029) and burst pressure higher for MAS (393 cm H2 O) than HS (180 cm H2 O; p = .012).

CONCLUSION

This study demonstrated the feasibility of a suture-free technique of canine ureteral resection-anastomosis using a commercially available MAS. The MAS anastomosis was faster and had higher burst strength compared with the HS anastomosis.

Primary ureteral giant cell sarcoma in a Pomeranian

An 8-year-old male neutered Pomeranian dog was presented to the Veterinary Teaching Hospital at Oregon State University for surgical treatment of hydronephrosis of the left kidney and a left cranial abdominal mass. A primary ureteral mass was found during exploratory surgery, and the mass was resected and ureteral anastomosis was performed. Cytologic evaluation of the mass revealed 3 distinct cell populations, including a large number of multinucleated giant cells, a moderate number of thin spindle-shaped cells, and cohesive clusters of transitional epithelial cells. The cytologic diagnosis was giant cell sarcoma. The diagnosis was confirmed by histologic examination, and immunohistochemical staining was performed. The spindle-shaped cells and multinucleated giant cells were both immunoreactive for vimentin and spindle-shaped cells for S-100. Tumor cells did not express wide-spectrum cytokeratin, broad-spectrum muscle actin, smooth muscle actin, sarcomeric actin, desmin, BLA36, Mac 387, synaptophysin, neuron-specific enolase, glial fibrillary acid protein, or von Willebrand factor. These findings are most consistent with an anaplastic sarcoma with giant cells. This is the first case report of a primary ureteral giant cell sarcoma in a dog.

Ureteral spindle cell sarcoma in a dog

A five-year-old, female spayed Labrador retriever was presented for further investigation of an intra-abdominal mass. Abdominal exploration showed a large mass arising from the right ureter and a ureteronephrectomy was performed. Histopathology of the ureteral mass was consistent with a spindle cell sarcoma. The patient recovered well, but five months later was diagnosed with another tumour, this time in her left abdominal wall. The owners decided not to pursue further treatment and euthanasia was performed a month later.

Ureteral sarcoma in a dog

A ureteral sarcoma was diagnosed in a nine-year-old Weimaraner dog with gross haematuria, severe unilateral hydronephrosis, and hydroureter. Treatment consisted of unilateral nephrectomy and ureterectomy. This case was compared with 14 other ureteral tumours reported in the veterinary literature. Only three previous reports concerned a malignant ureteral tumour. Urinary tract neoplasms mainly involve the bladder and the kidney, and more rarely the urethra. The purpose of this paper is to report a rare case of malignant ureteral tumour in a dog.