MALIGNANT COLONIC NEOPLASIA IN CATS - 46 CASES (1990-1996)

Objective - To evaluate a group of cats with malignant colonic neoplas ia and to identify factors related to survival time. Design - Retrospe ctive study. Animals - 46 cats with malignant colonic neoplasia. Proce dure - Information on signalment, diagnostic findings, histopathologic diagnosis, surgical procedure performed, identification of nodal meta stasis at surgery, type of chemotherapy administered, and survival tim e was obtained from the medical record of each cat. A diagnosis of mal ignant colonic neoplasia had been established by histologic examinatio n of endoscopic biopsy specimens (3 cats), biopsy specimens obtained d uring laparotomy (38), or necropsy specimens (5). Results - Mean age o f cats was 12.5 years (range, 6 to 18 years). Ultrasonography was usef ul 84% of the time in localizing the mass to the intestine. Three cats had endoscopic biopsy, 9 had incisional biopsy, 21 had mass resection , and 8 had subtotal colectomy performed. Histopathologic diagnoses in cluded adenocarcinoma (21 cats), lymphoma (19), mast cell tumor (4), a nd neuroendocrine carcinoma (2). Clinical Implications - Obtaining cle an margins at surgery seems to increase survival time in cats with mal ignant colonic neoplasia. Metastasis at the time of surgery decreases survival time. Data from this study indicate that the survival time of certain cats with colonic lymphoma may not be affected by chemotherap y. Cats with an unidentified colonic mass should receive a subtotal co lectomy to increase survival time. Cats with colonic adenocarcinoma sh ould receive a subtotal colectomy with consideration of doxorubicin ad ministration to increase survival time.