A splenic mast cell tumor in an 11-year old Siamese cat: Surgery perspective

Dr. Jose GuevaraCats with splenic mast cell tumors frequently present in a stable condition, but many have a chronic history of vomiting, anorexia, lethargy or weight loss.1-5 After tumor staging, preoperative treatments should address hematologic abnormalities, gastrointestinal protection and prophylactic blockade of histamine receptors. About 29% to 41% of cats with splenic mast cell tumors are anemic at the time of presentation.1,3-7 In one study, the median packed cell volume was 17% prior to transfusion.3 Studies report that between 15% and 73% of cats will require blood products perioperatively.3,5 The outcome in cats given a transfusion was worse than that of cats that did not require any blood products.3 Additional hematologic abnormalities that have been reported-but have not demonstrated clinically significant effects-include prolonged clotting times,4 hyperglobulinemia,2 and thrombocytopenia.5

Splenectomy in cats has traditionally been performed through an open laparotomy technique, but a recent report has described the use of laparoscopic and laparoscopic-assisted techniques for splenectomy and biopsy collection.8 Laparoscopy may be a viable option for patients with mild to moderate splenomegaly or modestly sized splenic masses.8 It is hypothesized that the use of laparoscopic splenectomy techniques may result in diminished postoperative pain and a more rapid return to normal function in cats,8 as has been seen in human and canine patients.9 However, only a small number of cases have been reported and clinical trials are lacking. For staging purposes and to guide future therapy, the abdominal organs should be evaluated and biopsies should be collected from grossly abnormal tissues as well as from the most common sites of metastases, such as the liver and visceral lymph nodes.1

Perioperative complications of splenectomy for removal of a visceral mast cell tumor include hemorrhage, mast cell degranulation and vascular compromise to adjacent organs.1,3,10 Significant, and potentially fatal, hemorrhage may result from damage to the splenic capsule or inadequate ligation of splenic vessels.10 Bleeding may resolve during the procedure, as is the case with iatrogenic trauma to the capsule, or it may require additional surgical intervention if continued hemorrhage is suspected.10 The release of mast cell mediators when cells degranulate can result in death.2 Vascular compromise of the left limb of the pancreas may occur if the splenic artery is ligated proximal to the pancreatic artery or one of its branches.10 It may be necessary to perform a partial pancreatectomy if the pancreas becomes ischemic postoperatively.10 Other complications include recurrence of systemic neoplasia resulting in gastric ulceration or intestinal perforation, infection and incisional complications. Postoperative treatment protocols should include the use of an analgesic, such as buprenorphine,8 for the first week after surgery.

References

1. Liska W, MacEwen E, Zaki F, et al. Feline systemic mastocytosis: a review and results of splenectomy in 7 cases. J Am Anim Hosp Assoc 1979;15:589-597.

2. Withrow SJ, Page R, Vail DM. Mast cell tumors. In: Small animal clinical oncology. 5th ed. St. Louis, Missouri: Elsevier, 2013.

3. Kraus KA, Clifford CA, Davis GJ, et al. Outcome and prognostic indicators in cats undergoing splenectomy for splenic mast cell tumors. J Am Anim Hosp Assoc 2015;51:231-238.

4. Feinmehl R, Matus R, Mauldin GN. Splenic mast cell tumors in 43 cats (1975–1992), in Proceedings. Annual Veterinary Conference of the Veterinary Cancer Society 1992;12:50.

5. Gordon SSN, McClaran JK, Bergman PJ, et al. Outcome following splenectomy in cats. J Feline Med Surg 2010;12:256-261.

6. Skeldon NCA, Gerber KL, Wilson RJ, et al. Mastocytaemia in cats: prevalence, detection and quantification methods, haemotological associations and potential implications in 30 cats with mast cell tumours. J Feline Med Surg 2010;12:960-966.

7. Allan R, Halsey TR, Thompson KG. Splenic mast cell tumour and mastocytaemia in a cat: case study and literature review. N Z Vet J 2000;48:117-121.

8. O'Donnell E, Mayhew P, Culp W, et al. Laparoscopic splenectomy: operative technique and outcome in three cats. J Feline Med Surg 2013;15:48-52.

9. Culp WTN, Mayhew PD, Brown DC. The effect of laparoscopic versus open ovariectomy on postsurgical activity in small dogs. Vet Surg 2010;38:811-817.

10. Tobias K, Johnston S. Spleen. In: Veterinary surgery: small animal. 1st ed. St. Louis, Missouri: Elsevier, 2011.