Mucinous Rectal Adenocarcinoma in a Urutu Snake (Bothrops alternatus)

A 15-year-old captive female Urutu snake (Bothrops alternatus) was presented with anorexia, apathy, dehydration, pale mucous membranes and marked enlargement of the caudal third of the coelomic cavity. Radiographs and ultrasonography were suggestive of faecal impaction or neoplasia. Post-mortem findings consisted of solid faecal impaction of the intestines, secondary to obstruction caused by a rectal tumour. Cytological examination of impression smears of the tumour revealed polygonal to round neoplastic cells arranged in clusters in an abundant extracellular mucinous matrix. Histologically, there was transmural growth of neoplastic epithelial cells arranged in small nests or individually and immersed in abundant extracellular mucin lakes. The neoplastic cells were immunopositive for cytokeratin. Clinical and pathological aspects indicated a diagnosis of mucinous rectal adenocarcinoma.

Colonoscopic and histologic features of rectal masses in dogs: 82 cases (1995-2012)

OBJECTIVE To evaluate colonoscopic and histologic features of rectal masses in dogs. DESIGN Retrospective case series. ANIMALS 82 client-owned dogs with rectal masses that underwent colonoscopy. PROCEDURES Medical records of dogs with rectal masses that underwent colonoscopy were reviewed. History, signalment, clinical signs, results of physical examination, diagnostic imaging findings, and results of colonoscopy (including complications) were recorded. When available, tissue samples obtained during colonoscopy and by means of surgical biopsy were reviewed by a single board-certified pathologist. Histologic features and tumor grade (when applicable) of tissue samples obtained during colonoscopy versus surgical biopsy were compared. RESULTS Multiple rectal masses were observed during colonoscopy in 6 of the 82 dogs, but no lesions were visualized orad to the colorectal junction. Results of histologic evaluation of surgical biopsy specimens were consistent with a diagnosis of epithelial neoplasia in 58 of 64 dogs, of which 71% were classified as benign adenoma or polyp and 29% were classified as adenocarcinoma in situ or adenocarcinoma. Complications of colonoscopy occurred in 3 of 82 dogs but were considered minor. A discrepancy in diagnosis occurred in 5 of 16 dogs for which both colonoscopic and surgical biopsy samples were available for histologic review. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that multiple rectal masses are uncommon in dogs, and secondary lesions orad to the colorectal junction were not found in this study. Colonoscopy was associated with few complications, but the need for colonoscopic assessment of the entire colon in this patient population may merit reevaluation.

Malignant rectal melanoma in 2 dogs

Two rare cases of malignant rectal melanoma in dogs are described. Tumors were locally invasive and composed of spindle cells arranged in interweaving bundles, sheets, and nests within preexisting fibrovascular stroma. Mitotic count was high. The diagnosis was achieved based on histopathology and immunohistochemistry for PNL2 and melan-A.

Poorly Differentiated Rectal Carcinoid in a Cow

A carcinoid tumor was found as a solitary soft mass in the wall of the rectum adjacent to the anorectal junction in an adult Holstein cow. Microscopically, the tumor involved the submucosa and partly invaded the muscular layer. It consisted of a compact arrangement of a great number of large polygonal cells and a small number of small dark cells, some of which showed argyrophilia (Grimelius positive). Immunohistochemically, both types of tumor cells were positive for vimentin, keratin, and S-100 protein and weakly positive for neuron-specific enolase (NSE), whereas they were negative for some endocrine markers such as chromogranin A, insulin, glucagon, somatostatin, serotonin, adrenocorticotropic hormone, and calcitonin. Electron microscopy revealed membrane-bound secretory granules in the cytoplasm of some small dark cells. In such a poorly differentiated carcinoid, the morphologic characteristics of the small dark cells were strong evidence for the diagnosis. This is the first description of a poorly differentiated carcinoid developing in the rectum of a cow.

Evaluation of transanal endoscopic treatment of benign canine rectal neoplasia

OBJECTIVES

To evaluate transanal endoscopic treatment in the management of benign canine rectal neoplasia.

METHODS

A retrospective study was carried out to evaluate the response to transanal endoscopic treatment in 13 dogs with extensive rectal neoplasia that was considered inoperable by conventional surgical techniques but was indicated as benign by previous biopsy.

RESULTS

Tumours affected the lengths of rectal mucosa varying from 2 to 13 cm. Between 25 and 100 per cent of the rectal circumference was affected in each case. Transanal endoscopic treatment of canine rectal neoplasia was curative in five dogs, palliative in three and associated with a poor result in the remaining five. Complications of the technique included rectal perforation, leading to peritonitis and death.

CLINICAL SIGNIFICANCE

Transanal endoscopic treatment can be recommended as an alternative to radical, full-thickness rectal excision for the management of extensive but benign canine rectal neoplasia. Owners should be informed that the treatment may be palliative rather than curative and that complications, if they occur, can be fatal. Dogs should be hospitalised for at least five days after treatment and observed for signs of potentially fatal complications such as rectal perforation.

Surgical Excision of Primary Canine Rectal Tumors by an Anal Approach in Twenty-Three Dogs

OBJECTIVE

To describe an anal approach for excision of primary rectal tumors in dogs and to report outcome.

STUDY DESIGN

Retrospective study.

ANIMALS

Dogs (n=23) with primary rectal tumors.

METHODS

Review of medical records (1990-2000) of dogs with primary rectal neoplasia excised surgically using an anal approach with rectal prolapse. With dogs anesthetized, the rectum was prolapsed, stabilized with stay sutures during tumor excision with 1 cm margins to the level of the muscularis, then the rectal mucosa was sutured.

RESULTS

Each dog had only 1 tumor type (adenocarcinoma [8], solitary polyp [5], carcinoma [4], plasmacytoma [2], adenoma [1], leiomyoma [1], mucinous carcinoma [1], and papilloma [1]). Mean tumor volume was 3.1 cm(3) (range 0.1-37.7 cm(3)). Postoperative complications (rectal bleeding [5], tenesmus [4]) were mild and resolved within 7 days after surgery; another dog had partial mucosal dehiscence identified at 6 days. The primary tumor was incompletely excised in 1 dog (4.3%), and local recurrence occurred 16 and 24 months after surgery in 2 dogs. Outcome beyond the immediate postoperative period was known for 18 dogs, including 2 dogs still alive. Mean postoperative disease-free interval for these 18 dogs was 36.8 months (range 5-84 months).

CONCLUSION

Surgical excision of tumors of the caudal rectum can be accomplished through the anus after rectal prolapse.

CLINICAL RELEVANCE

An anal approach facilitated by rectal prolapse should be considered as a viable option for the surgical treatment of selected cases of tumors of the caudal aspect of the rectum in dogs.

Cohort study of COX-1 and COX-2 expression in canine rectal and bladder tumours

OBJECTIVES

To determine the role that cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) play in malignant transformation in canine transitional cell carcinoma and rectal tumours.

METHODS

Histological sections of 21 canine rectal adenocarcinomas and 18 canine transitional cell carcinomas were stained for COX-1 and COX-2. Mann-Whitney non-parametric tests were applied to determine if there was any relationship between the percentage of cells expressing COX-1 or COX-2, and between COX-1 and COX-2 staining intensity and age, breed or sex.

RESULTS

For rectal adenocarcinomas, 19.0 per cent of the sections were negative for COX-1 and COX-2. A further 38.1 per cent of the sections were negative for COX-2 but positive for COX-1, and 38.1 per cent of the sections had rare or occasional single cells positive for COX-2. No significant differences were found in COX staining when compared with age, breed or sex. For transitional cell carcinomas, all of the sections were positive for COX-1 and COX-2. For COX-2 staining, 16.7 per cent had more than 30 per cent positive cells. For COX-1 staining, 38.9 per cent had more than 30 per cent positive cells. There was a significant increase in the percentage of COX-1 positive cells in small breed dogs (P = 0.0337).

CLINICAL SIGNIFICANCE

The variations in COX expression reported in this study may explain the differences in the clinical response of transitional cell carcinomas and rectal adenocarcinomas following treatment with non-steroidal anti-inflammatory drugs.

Use of an incontinent end-on colostomy in a dog with annular rectal adenocarcinoma

An 11-year-old, mixed-breed dog with dyschezia, tenesmus and haematochezia was presented. A rectal stricture caused by an adenocarcinoma was diagnosed. Following the failure of a rectal 'pull-through' procedure, which dehisced seven days later, an incontinent end-on colostomy was performed, allowing amputation of the colorectum with the anus and perineal skin. A two-piece device consisting of a flange and a drainable pouch was used for postoperative faecal evacuation and collection. Mild peristomal dermatitis was the only complication. Patient management was easily carried out by the owner at home, and the dog survived for four months with a satisfactory quality of life. Incontinent end-on colostomy may prove to be a useful treatment for canine annular colorectal tumours.

Space-occupying leiomyoma in the pelvic canal of a dog

A large space-occupying mass was found in the pelvic canal of an 11-year-old, entire female shih tzu with rectal tenesmus and dyschezia. Computed tomography revealed an extraluminal mass located on the dorsal aspect of the rectum, causing complete rectal obstruction. Histopathological examination of biopsy tissue identified it as a leiomyoma. The tumour was successfully removed by blunt dissection, via a dorsal approach to the rectum, and there were no complications after surgery.

Gastroduodenal adenocarcinomas and rectal adenoma in a cougar (Felis concolor) infected with Helicobacter-like organisms and spirochetes

A 14-year-old female cougar died from gastroduodenal adenocarcinomas and rectal adenoma. At necropsy, polypoid tumor masses of various sizes were scattered on the mucosal surfaces of the stomach, duodenum, and rectum. Histologically, the gastric tumor was diagnosed as an intestinal type adenocarcinoma and the tumor cells metastasized to the mesenteric lymph nodes, spleen, and lung. Helicobacter-like organisms were detected in the lumina lined by foveolar epithelium. In the duodenum, the carcinoma cells were localized in the limina propria and many of them were intensely positive for proliferating cell nuclear antigen (PCNA). In contrast, the rectal adenoma had a lower number of PCNA-positive cells. In the rectum, chronic inflammation with numerous spirochetes was also noted. These results indicated that the occurrence of the gastrointestinal tumors might be associated with the bacterial infection described above.

Neutrophilic leucocytosis in a dog with a rectal tumour

A nine-year-old cocker spaniel was presented with a three-year history of intermittent haematochezia and a palpable rectal mass. Routine haematological examination revealed a marked mature neutrophilia (86.04 x 10(9) neutrophils/litre). A friable mass in the middle portion of the rectum was detected on colonoscopy. Histopathological examination of mucosal pinch biopsies collected from the mass confirmed a diagnosis of adenomatous tubulopapillary polyp. Some evidence of malignant transformation was observed. Palliative treatment with piroxicam suppositories at a dose of 1.4 mg/kg administered rectally every third day was instituted. On re-evaluation, 47 days after starting medical therapy, the owner reported a significant reduction in haematochezia and tenesmus; however, frequency of defecation had remained unaltered. Routine haematology revealed a reduction in the mature neutrophil count (33.67 x 10(9) neutrophils/litre). This report describes a case of a rectal tumour associated with a neutrophilic leucocytosis, which responded to palliative therapy with piroxicam suppositories.

Preliminary clinical observations on the use of piroxicam in the management of rectal tubulopapillary polyps

Rectal tubulopapillary polyps were diagnosed in eight dogs following proctoscopy and mucosal pinch biopsy. Histological examination of the pinch biopsies revealed evidence of malignant transformation in three of the cases. The remaining cases were diagnosed as benign polyps. Inflammatory changes were observed in four cases. Seven dogs were treated with piroxicam suppositories and one with oral piroxicam. All dogs were re-examined after four to six weeks of piroxicam therapy and the extent of haematochezia, tenesmus and faecal mucus production was reduced in all cases. The owners of seven of the dogs considered the improvement in clinical signs to be good or excellent. Cases with and without evidence of inflammation responded equally well. This finding supports the hypothesis that piroxicam has an antineoplastic effect due to apoptosis and alteration in the cell cycle. Medical management with piroxicam may provide a non-invasive treatment option for dogs with rectal polyp formation in which surgical treatment is likely to be associated with complications such as incontinence, infection and wound breakdown, or where the owner declines such treatment.

Transanal endoscopic treatment of benign canine rectal tumours: preliminary results in six cases (1992 to 1996)

Transanal endoscopic resection and cautery of benign rectal tumours was performed in six dogs with extensive and/or inaccessible rectal neoplasia. The results were encouraging, with three dogs cured and the quality of life of a further two improved for a significant time. The remaining dog died as a result of rectal perforation. Transanal endoscopic treatment of extensive and/or inaccessible benign canine rectal tumours offers an alternative to more radical techniques such as pull-through surgery.

Rectal ganglioneuroma in a dog

An 18-month-old, spayed female Australian terrier cross was presented with a 10-month history of chronic large bowel diarrhea. Ulceration and two proliferative masses in the rectum were seen on colonoscopy. Surgical resection was performed to remove the masses, and the dog recovered without complications related to surgery. Histopathology was consistent with the diagnosis of ganglioneuroma. The dog had no clinical signs of disease within three months of surgery and was completely normal 2.5 years after diagnosis. This is the first report providing follow-up and successful outcome of a ganglioneuroma in the gastrointestinal tract of a dog.

Intestinal multinodular A lambda-amyloid deposition associated with extramedullary plasmacytoma in three dogs: clinicopathological and immunohistochemical studies

Intestinal extramedullary plasmacytomas (EMPs) are rare tumours in dogs. Three cases of canine intestinal EMP with amyloid deposits are described in this report. These tumours, which were located in the rectal submucosa, had variable numbers of well-differentiated plasma cells and fewer multinucleated giant cells of plasmacytoid and histiocytic morphology, admixed with abundant amyloid. Two cases had metaplastic cartilage and bone within the amyloid deposits. Immunohistochemically, the plasma cells of all three tumours reacted for lambda-light chains of immunoglobulins but not for kappa-chains, indicating monoclonality. Plasma cells of two tumours were also positive to CD79a antiserum. Amyloid deposits were labelled with an A lambda (amyloid of immunoglobulin lambda-light chain origin) antiserum but not with antisera against its precursor protein, the immunoglobulin lambda-light chains, indicating possible conformational changes of amyloidogenic proteins during their transformation into amyloid.

Intestinal extramedullary plasmacytoma associated with amyloid deposition in three dogs: an ultrastructural and immunoelectron microscopic study

Samples from rectal plasmacytoma in three adult dogs that were diagnosed by light microscopy and immunohistochemistry were examined by electron microscopy. The most common cell type had typical plasmacytoid features. A second cell type was a plasmacytoid giant cell with single or multiple eccentric nuclei, irregular nuclear membrane, abundant and dilated rough endoplasmic reticulum, and numerous electron-dense granules. The third cell type was a histiocytic giant cell that intermingled with plasmacytoid cells. All three tumors had abundant amyloid, mainly in the interstitium but also within histiocytic cells and less commonly in plasma cells or plasmacytoid giant cells. Extracellular and intracellular amyloid fibrils and the contents of membrane-bound electron-dense bodies of plasma cells reacted with antibody to lambda-light chain of immunoglobulins by immunogold staining.

Gastrointestinal adenocarcinomas metastatic to the testes and associated structures in three dogs

Primary testicular neoplasms are common in dogs, but metastases to the testes are rare. Three dogs had enlargement of the testes and associated structures. Upon histological examination, the enlargements were due to metastatic adenocarcinomas. Further examination identified the gastrointestinal tract as the primary site of the metastatic neoplasms in all three cases. The testicular metastases reflected widespread metastatic disease. When metastatic adenocarcinoma is found in the testes and associated structures in dogs, the gastrointestinal tract should be examined closely for a primary tumor site.

[Anorectal causes of constipation problems in dogs]

This survey shows the most popular reasons for problems of defaecation in dogs. Beyond the pathogenesis, diagnosis and therapy will be discussed.

Rectal biopsy diagnosis in horses with clinical signs of intestinal disorders: a retrospective study of 116 cases

The histology from rectal biopsy specimens taken 1980-1990 on 131 occasions from 116 horses, age 1-18 years, with clinical signs of intestinal disease was evaluated and classified retrospectively. In 40 horses, autopsy results were studied for comparison. Biopsy specimens (21 horses) and post mortem rectal tissue (9 horses) from 30 healthy horses, age 4-22 years, were used as controls. In 105 clinical cases, a biopsy was performed on only one occasion, while repeat biopsy was performed in 11 cases. Specimens showed pathological changes in 60 horses. The findings were classified into acute, chronic or chronic active simple proctitis, granulomatous enteritis, eosinophilic granulomatosis/gastroenteritis, eosinophilic proctitis, erosive/ulcerative proctitis, pseudomembranous proctitis, proctitis with vasculitis and malignant lymphoma. Mild scattered neutrophil infiltration in the lamina propria was found in controls, but neutrophils in crypt or surface epithelia were abnormal findings. Depletion or hyperplasia of goblet cells sometimes accompanied inflammation. Simple proctitis occurred in association with malignant lymphoma and various inflammatory disorders of the gastrointestinal tract apparent at autopsy. Eosinophilic granulomatosis/gastroenteritis and granulomatous enteritis were diagnosed from biopsy specimens in 6 of 12 and 4 of 9 cases, respectively, of these diseases confirmed at autopsy. Reduction of acid mucins in goblet cells was a prominent feature of eosinophilic granulomatosis. Rectal biopsy was found to be a useful adjunct for evaluation of intestinal disease in the horse.

Adenocarcinoma in the rectum of a capped langur (Presbytis pileata)

A rectal adenocarcinoma in a 22-year-old capped langur histologically resembling those in human cases is reported. An ill-defined diffuse tumor with fibrously firm rectal wall showed diffuse infiltrative growth of signet-ring cancer cells. Immunohistochemistry demonstrated positive staining for CEA, lysozyme, EMA, keratin and B72.3.

Scirrhous adenocarcinoma of the rectum in a cow

Clinical and pathological examinations were performed on a 3-year-old Holstein-Friesian cow with scirrhous adenocarcinoma of the rectum. Hemorrhagic diarrhea causing rectal stenosis was a principal clinical manifestation. Microscopically, cancerous transformation of the intestinal epithelium was observed in the rectal crypts. Irregular glandular arrangements containing PAS positive and eosinophilic mucus were observed in the lumen, which were surrounded by scirrhous collagenous fibers. The neoplastic epithelial cell had round or ovoid nucleus and slightly eosinophilic cytoplasm. Metastatic lesions were localized in the marginal and medullary sinuses of the anorectal lymph nodes.

Metastatic extramedullary plasmacytoma of the colon and rectum in a dog

Stage-3 extramedullary plasmacytoma of the large intestine was diagnosed in an 8-year-old Labrador Retriever. Three primary tumors were located in the colon and rectum, with metastasis to local lymph nodes and the spleen. The disease was associated with a monoclonal serum protein spike identified as IgG. Treatment consisted of surgical excision followed by chemotherapy, using melphalan and prednisone. The dog remained free from clinical signs of disease and adverse effects of the chemotherapy at 9 months. Findings in this dog indicated that extramedullary plasmacytoma may be an aggressive disease, associated with spread to distant sites and monoclonal gammopathy.

Paraneoplastic leukocytosis associated with a rectal adenomatous polyp in a dog

A dog with a rectal adenomatous polyp had extreme neutrophilic leukocytosis, monocytosis, and eosinophilia consistent with a paraneoplastic syndrome. Resolution of the leukogram abnormalities after tumor excision supported this belief. Except for a lack of circulating myeloblasts, the dog had leukogram findings consistent with a neutrophilic leukemoid reaction.

Standing rectal and tail surgery

A variety of rectal, perirectal, and coccygeal surgeries can be performed in the standing equine patient if appropriate chemical and physical restraints are available and adequate regional anesthesia can be achieved. Some rectal tears and most rectal prolapses, mass lesions, perirectal abscesses, rectal biopsies, and selected injuries of the tail can be managed without prohibitive difficulty. Severe injuries that compromise the small colon cranial to the peritoneal reflection may require flank laparotomy, midline celiotomy, or humane euthanasia to manage the disease process effectively and appropriately. The foremost perioperative consideration beyond the use of effective restraint is the management of tenesmus in horses with rectal tears or prolapses. Medications to control bowel motility, epidural anesthesia, antiinflammatory analgesics, and topical compounds adequate to soothe and lubricate inflamed rectal tissues are an important adjunctive therapy in the aftercare of these surgical patients. Of nearly equal importance is the requirement that a loose fecal consistency be maintained with laxative diets, psyllium, and mineral oil. Failure to maintain a loose consistency of stool after treatment of these conditions may lead to rectal impaction or incisional dehiscence and surgical failure.

A retrospective evaluation of the rectal pull-through technique. Procedure and postoperative complications

Ten animals (8 dogs and 2 cats) with distal rectal lesions were treated by surgically resecting the affected segment of the rectum by the rectal pull-through technique. There were four malignant tumors, three benign tumors, two inflammatory lesions, and one malignant tumor that extended histologically to the margins of a previous surgical excision. Postoperative complications were tenesmus (7 animals), fecal incontinence (4 animals), rectal bleeding (4 animals), and abscess formation (1 animal). Dehiscence and stricture were not observed. The four animals with malignant tumors survived less than 12 months after surgery. One of the four animals still living has persistent fecal incontinence. The rectal pull-through technique is described and illustrated.

Colorectal adenocarcinoma in dogs: 78 cases (1973-1984)

Colorectal adenocarcinoma was diagnosed in 78 dogs. Clinical signs in all 78 dogs included tenesmus, hematochezia, and dyschezia; most of the dogs had clinical signs less than or equal to 12 weeks before examination. Ultimately, most dogs were euthanatized because of the severity of clinical signs. Proctoscopy and colonoscopy were essential for complete assessment of extent of disease. Tumors were classified by gross appearance and included single, pedunculated masses, 2 or more nodular masses, and annular or intraluminal masses. In dogs in which survival time was compared with location and gross appearance of the tumor, dogs with annular masses had the shortest mean survival time (1.6 months), and dogs with single, pedunculated, polypoid tumors had the longest mean survival time (32 months). The rectum was a more common site than the colon, with 48.2% of the tumors developing in the middle portion of the rectum. Six different modes of surgical treatment were used, depending on the location and type of mass. Dogs that did not have surgical treatment had a mean survival time of 15 months. Mean survival time in the surgically treated dogs varied slightly according to mode of treatment; they survived 7 to 9 months longer than the untreated dogs. Dogs that underwent cryosurgery and local excision had the longest survival times (24 and 22 months, respectively). Statistical analysis disclosed a significantly longer survival time for dogs treated by excision or cryosurgery, as opposed to dogs undergoing biopsy only (P = 0.001). Statistical difference in survival times was not found between dogs that had mass excision and those that had cryosurgery.

Rectal leiomyosarcoma in a horse

A mass originating from the dorsal rectal wall of a 4-year-old mare was diagnosed as a leiomyosarcoma. General anesthesia and meticulous surgical dissection were required to effect removal. In spite of incomplete excision, as indicated by histologic sections, the mass has not recurred in the 18 months since removal.

Tumors of the alimentary tract

Neoplasms of the canine and feline alimentary tract represent diagnostic and therapeutic challenges for the veterinarian in practice. Careful attention to historical details and thorough and repeated examination are of paramount importance in evaluating animals with chronic digestive disturbances. By judicious use of ancillary studies such as plain and contrast radiography, endoscopy, and exploratory surgery, the clinician may arrive at a diagnosis earlier in the course of a neoplasm. This in turn may facilitate more efficacious treatment. A particularly interesting aspect of tumors of the gastrointestinal tract is their frequent association with environmental carcinogens. By being aware of these relationships, veterinarians stand a better chance of reaching the ultimate goal of cancer therapists--the prevention of malignant disease.

Rectal neoplasia in the dog: a clinicopathological review of 31 cases

A clinicopathological review was made of 31 cases of canine rectal neoplasia. The adenomatous polyp was the commonest tumour and had the best prognosis. With the exception of adenocarcinomas the results of surgical excision of malignant neoplasms, including two cases of rectal lymphosarcoma, were encouraging.

[Lymphosarcoma as a rare cause of rectal prolapse in a dog]

A case is presented of a dog with a lymphocytic lymphosarcoma of the rectum without systemic involvement. The dog showed bloody stools and rectal prolapse. The diagnosis and treatment is discussed.

Canine intestinal carcinoids

Intestinal carcinoids were diagnosed in three aged dogs. Two of the neoplasms occurred in the rectum and one at the cecocolic junction. Judged by histologic criteria, all three carcinoids were considered to be malignant. Amyloid was present in both rectal tumors. In each tumor the diagnosis was confirmed by the finding of electron-dense intracytoplasmic secretory granules in the neoplastic cells.

Colorectal polyps of the dog: a clinicopathologic study of 17 cases

Seventeen cases of colorectal polyps in the dog were seen at the Ontario Veterinary College over a 12-year period. The mean age of occurrence was 6.9 years, and males and females were almost equally affected. The Collie was the most frequently affected breed (4/17). The clinical signs were typically dyschezia, periodic intermittent diarrhea and melena, and rectal prolapse of the polyp. The histopatholic classifcation were hyperplastic polyp (1), papillary adenoma (1), tubular adenoma (4), papillotubular adenoma (10), and unclassified (1). Severe epithelial atypia, likely carcinoma in situ, was apparent in 5 of the papillotubular adenomas. Retrospective analysis of survival data after polypectomy suggested a good prognosis, but the results were inconclusive and it is possible that some of the polyps represented premalignant lesions. Large polyps (greater than 1 cm in diameter) frequently had marked epithelial atypia and were considered more likely to recur or to become malignant.

Pseudohyperparathyroidism associated with perirectal adenocarcinomas in elderly female dogs

In 8 elderly female dogs a syndrome of hypercalcaemia and hypophosphataemia was found in association with a perirectal adenocarcinoma. Following removal of the tumour the hypercalcaemia resolved within two days in four of the five operated animals.

Feline intestinal adenocarcinoma. A clinicopathologic study of 22 cases

Twenty-two cases of intestinal adenocarcinoma were diagnosed in an 11-year survey of 3145 feline necropsies. Histologically, tumors were grouped into four classes: (1) carcinoma with solid groups of cells, (2) adenocarcinoma with solid and acinar cells, (3) papillary adenocarcinoma, and (4) mucinous adenocarcinoma. Tumors were commonest in the ileum. Connective tissue, as well as epithelial metaplasia, were associated more often in this group of intestinal adenocarcinomas nomas than seen before. Hypertrophy and hyperplasia of muscular layers of the unaffected sections of intestines were seen in most of the small bowel and in half of the large bowel carcinomas in this series.