Evaluation of the histopathological extent of neoplastic infiltration in intestinal tumours in cats

Abstract

With the exception of intestinal lymphoma, surgery is the most commonly recommended treatment for solitary feline intestinal tumours. However, there is a lack of evidence to substantiate resection margin recommendations for these tumours. The aim of this study was to add knowledge concerning resection margins for discrete intestinal masses in cats. Thirty confirmed feline intestinal tumours removed at veterinary centres across the UK from March 2017 to March 2018 underwent histological assessment at the palpable edge of the intestinal tumour and then at every 1 cm increment to the surgeon‐cut tissue border in oral, aboral and mesenteric directions. Histological margin recommendations were developed for carcinoma and lymphoma tumour types and non‐lymphoma intestinal tumours collectively. Seventeen intestinal lymphomas, nine carcinomas, two sarcomas and two mast cell tumours were evaluated in this study. Seven of the nine intestinal carcinomas would have been completely removed with histological margins of 4 cm in oral and aboral directions. Both sarcomas and one mast cell tumour would have been removed in their entirety with 4 cm histological margins in oral and aboral directions. There was extensive and varied microscopic invasion of intestinal tissue away from discrete intestinal lymphomas in the majority of the cases in this study. There is increasing evidence in veterinary as well as human literature supporting the role of surgical resection in the treatment of discrete intestinal lymphoma. If surgery is to be considered this study supports the removal of the gross tumour only. A histological margin of 4 cm should be considered, where possible, for intestinal masses other than lymphomas.

Pathological Findings in Gastrointestinal Neoplasms and Polyps in 860 Cats and a Pilot Study on miRNA Analyses

“…Improved diagnostics and therapeutic options, as well as an increasing willingness of patient owners to perform more advanced diagnostic measures, such as the immunohistochemical subtyping of lymphomas, may have contributed to the higher proportion of gastrointestinal lymphomas in the present pathologybased investigation. The low percentage of spindle cell tumours and mast cell tumours, along with the low incidence of neoplasms in cats younger than seven years of age, were consistent with the observations of other authors [7,[47][48][49]. However, we should be aware that data from pathological cases do not reflect the proportion of tumour diseases in cats in daily veterinary practice, since endoscopic or laparoscopic sampling is often only performed in the further course of the diagnosis of tumour diseases and only if advanced treatment is planned.…”

“…It has been shown that intestinal neoplasms in cats (except for lymphomas) should be resected with 4 cm margins in oral and aboral directions [49]. In our study, large intestinal carcinomas especially lacked free margins, probably due to the anatomical limitations of surgery.…”

“…In our study, large intestinal carcinomas especially lacked free margins, probably due to the anatomical limitations of surgery. Additional samples of regional lymph nodes were submitted in 307 cases of intestinal neoplasms, and 68% of them were affected by metastases, as reported by other studies [47][48][49]. Metastases were identified as a negative prognostic factor [48].…”

Comparative aspects of mast cell neoplasia in animals and the role of KIT in prognosis and treatment

“…Splenectomy is the standard therapy for cats with splenic mastocytosis and provides longer disease-free survival than chemotherapy alone (856 days vs. 342 days, respectively) (Evans et al, 2018). Cats with intestinal MCT historically carry a guarded prognosis and metastasis to mesenteric lymph nodes is common (Barrett et al, 2018;Morrice, Polton, & Beck, 2019;Sabattini et al, 2016). However, recent literature describes variable biologic behaviour of feline gastrointestinal MCT with the overall median survival time of 31 cats to be 531 days in one study (Barrett et al, 2018) and 35% of cats surviving more than 1-year post-diagnosis in a different study which included a case where no treatment or surgery was received (Sabattini et al, 2016).…”

Outcome and Prognostic Factors in Cats Undergoing Resection of Intestinal Adenocarcinomas: 58 Cases (2008–2020)

“…Rates of local and distant metastases have been reported to range from 55 to 76 percent ( 3 – 7 ). Wide surgical resection with or without adjuvant chemotherapy is currently the primary mode of therapy ( 2 , 8 , 9 ). Existing retrospective studies reporting on prognostic factors and survival times describe relatively small populations of cats, but consistently suggest that outcomes are highly variable and that prolonged survival times are occasionally observed in the presence of systemic disease ( 4 , 6 , 7 , 10 ).…”