Short- and long-term outcomes associated with anal sacculectomy in dogs with massive apocrine gland anal sac adenocarcinoma.

OBJECTIVE: To evaluate short- and long-term outcomes for dogs undergoing anal sacculectomy for massive (> 5 cm) apocrine gland anal sac adenocarcinoma (AGASACA). ANIMALS: 28 client-owned dogs with massive AGASACA. PROCEDURES: A retrospective multi-institutional study was performed. Pre-, intra-, and post-operative data was collected, and variables were statistically analyzed for associations with progression-free interval (PFI) and overall survival (OS). RESULTS: At the time of anal sacculectomy, 19 (68%) dogs underwent concurrent iliosacral lymph node extirpation, including 17 of 18 (94%) dogs with suspected nodal metastasis preoperatively. Five (18%) dogs experienced grade 2 intraoperative complications. Ten (36%) dogs experienced postoperative complications, including 1 grade 3 and 1 grade 4 complication. No dogs had permanent fecal incontinence, tenesmus, or anal stenosis. Nineteen dogs received adjuvant chemotherapy, radiation, or both. Local recurrence occurred in 37% of dogs. Dogs with lymph node metastasis at surgery were more likely than dogs without metastasis to develop new/progressive lymph node metastasis (10/17 [59%] vs 0/10 [0%]; P = .003) and distant metastasis (7/17 [41%] vs 0/10 [0%]; P = .026). Median PFI was 204 days (95% CI, 145 to 392). Median OS was 671 days (95% CI, 225 to upper limit not reached). Nodal metastasis at the time of surgery was associated with shorter PFI (P = .017) but not OS (P = .26). Adjuvant therapy was not associated with outcome. CLINICAL RELEVANCE: Dogs with massive AGASACA experienced prolonged survival following anal sacculectomy despite a high incidence of local recurrence and metastasis. Lymph node metastasis at the time of surgery was a negative prognostic indicator for PFI but not OS.

Complications associated with iliosacral lymphadenectomy in dogs with metastatic apocrine gland anal sac adenocarcinoma.

Objective: To report intraoperative and immediate postoperative complications associated with removal of metastatic iliosacral lymph nodes in dogs with apocrine gland anal sac adenocarcinoma. Animals: There were 136 client-owned dogs in the study. Procedure: Retrospective multi-institutional study. The database of collaborating institutions was searched for dogs with metastatic apocrine gland anal sac adenocarcinoma that underwent lymphadenectomy for removal of one or more iliosacral lymph nodes. Information of signalment, hematological abnormalities, abdominal computed tomography or ultrasound findings, number and size of enlarged lymph nodes, intraoperative and postoperative complications, treatment and outcome were collected. Results: The overall complication rate associated with metastatic iliosacral lymphadenectomy was 26.1%. The only intraoperative complication recorded was hemorrhage and was reported in 24 (17.6%) surgeries, 11 (45.8%) of which received a blood transfusion. Postoperative complications were reported in 10.4% of surgeries, and included edema formation (n = 4, 2.6%), unilateral or bilateral paraparesis (n = 4, 2.6%), hypotension (n = 3, 2.0%), surgical site infection (n = 2, 1.3%), abdominal incision dehiscence (n = 1, 0.6%), urinary incontinence (n = 1, 0.6%), and death (n = 1, 0.6%). The size of the iliosacral lymph nodes was significantly associated with a greater risk of complications, hemorrhage, and the need of transfusion during lymphadenectomy for metastatic apocrine gland anal sac adenocarcinoma. Conclusion: Complications associated with iliosacral lymphadenectomy for metastatic apocrine gland anal sac adenocarcinoma are relatively common and mostly relate to hemorrhage. These complications are significantly associated with the size of the extirpated metastatic lymph nodes. Clinical relevance: This retrospective study provides information for the clinician regarding the potential surgical complications for extirpation of metastatic iliosacral lymph nodes. These complications, although not common, can be severe and should be discussed with owners before surgery.

Objectif: Rapporter les complications peropératoires et postopératoires immédiates associées à l'ablation des ganglions lymphatiques ilio-sacrés métastatiques chez les chiens atteints d'un adénocarcinome des glandes apocrines des sacs anaux. Animaux: Il y avait 136 chiens appartenant à des clients dans l'étude. Procédure: Étude multi-institutionnelle rétrospective. La base de données des institutions collaboratrices a été recherchée pour les chiens atteints d'un adénocarcinome métastatique des glandes apocrines des sacs anaux qui ont subi une lymphadénectomie pour l'ablation d'un ou plusieurs ganglions lymphatiques ilio-sacrés. Des informations sur le signalement, les anomalies hématologiques, les résultats de la tomodensitométrie abdominale ou de l'échographie, le nombre et la taille des ganglions élargis, les complications peropératoires et postopératoires, le traitement et les résultats ont été recueillis. Résultats: Le taux global de complications associées à la lymphadénectomie ilio-sacrée métastatique était de 26,1 %. La seule complication peropératoire enregistrée était une hémorragie et a été rapportée dans 24 (17,6 %) chirurgies, dont 11 (45,8 %) ont reçu une transfusion sanguine. Des complications postopératoires ont été signalées dans 10,4 % des interventions chirurgicales et comprenaient la formation d'oedème (n = 4, 2,6 %), la paraparésie unilatérale ou bilatérale (n = 4, 2,6 %), l'hypotension (n = 3, 2,0 %), l'infection du site opératoire (n = 2, 1,3 %), la déhiscence de l'incision abdominale (n = 1, 0,6 %), l'incontinence urinaire (n = 1, 0,6 %) et le décès (n = 1, 0,6 %). La taille des ganglions ilio-sacrés était significativement associée à un risque accru de complications, d'hémorragie et à la nécessité d'une transfusion lors d'une lymphadénectomie pour un adénocarcinome métastatique des glandes apocrines des sacs anaux. Conclusion: Les complications associées à la lymphadénectomie ilio-sacrée pour l'adénocarcinome métastatique des glandes apocrines des sacs anaux sont relativement fréquentes et concernent principalement l'hémorragie. Ces complications sont significativement associées à la taille des ganglions lymphatiques métastatiques retirés. Pertinence clinique: Cette étude rétrospective fournit des informations au clinicien concernant les complications chirurgicales potentielles pour le retrait des ganglions lymphatiques ilio-sacrés métastatiques. Ces complications, bien que rares, peuvent être graves et doivent être discutées avec les propriétaires avant la chirurgie.(Traduit par Dr Serge Messier).

Updated Concepts in Oncologic Surgery: Apocrine Gland Anal Sac Adenocarcinoma and Mast Cell Tumors.

Advancements within the field of veterinary surgical oncology are constantly presenting themselves, especially with continued development of comprehensive cancer programs. With the use of more advanced imaging techniques within veterinary medicine, tumor staging is improving and techniques novel to veterinary medicine are being evaluated for potential clinical application. Recommended tumor staging and treatment approach for apocrine gland anal sac adenocarcinoma in dogs has evolved, with the anticipation of good long-term patient outcomes. Preoperative staging for mast cell tumors and recommendations for surgical margins to obtain for wide surgical excision is being reassessed by surgeons.

Post-operative complications following apocrine gland anal sac adenocarcinoma resection in dogs.

Describe the complications associated with surgical resection of primary apocrine gland anal sac adenocarcinoma (AGASACA) tumours study design multi-institutional retrospective cross-sectional cohort study Animals Client owned dogs with spontaneous disease using the Clavien-Dindo classification system, post-operative events were assigned and described. Logistic regression analysis was used to analyse for risk factors for a significant association with complications. One hundred sixty-one dogs were included in the analysis. The post-operative sequelae, complication, and failure to cure rates specific to the anal sac site was 14%, 17% and 1%, respectively. The majority (68%) of complications were grade II or higher, therefore requiring some form of intervention. Intra-operative complications were identified in 11 cases (7%) with anorectal wall perforation being most common. An intra-operative complication was significantly associated with post-operative complications (p < 0.001; OR 7.4) while anorectal wall perforation was the only significant risk factor on regression analysis (p < 0.001; OR 19). Surgical site infection was identified in 20 of 161 (12%) of cases. Local recurrence (LR) occurred in 18% of cases at a median of 374 days (95% CI: 318-430). The only risk factor significantly associated with LR was the presence of vascular or lymphatic invasion (p = 0.008; OR 3). Post-operative complications were relatively infrequent but the risk was significantly increased when there was an intraoperative complication during resection of a primary AGASACA tumour. This study provides information for the clinician regarding risk factors for post-operative complications.

A rare case of rectal cancer with perianal metastasis: a case report.

BACKGROUND: Cancer metastasis from colon cancer to an anal fistula is very rare. We herein reported a rare case in which local excision was performed for metastatic anal fistula cancer originating from rectal cancer. CASE PRESENTATION: A 68-year-old man was referred to our institution with a diagnosis of rectal cancer. He had complained of anal fistula for 5 years. Based on a recent history of cerebral infarction, Hartmann's operation was performed to treat the rectal cancer after the administration of preoperative chemotherapy for 3 months. However, 1 month after Hartmann's operation, the anal fistula was found to have worsened. Pelvic magnetic resonance imaging (MRI) revealed tumor formation at the perianal lesion. Metastatic anal fistula cancer originating from the rectal cancer was diagnosed based on the examination of the biopsied tissue. We selected local excision because the anal tumor had not invaded the surrounding tissue. There has been no recurrence in the 31 months after the curative operation. CONCLUSION: Metastatic cancer should be ruled out when treating left-sided colon cancer with anal fistula. Local excision is one possible treatment for metastatic anal fistula cancer.

Malignant perineal tumors in dogs: the contribution of computed tomography for staging and surgical planning / Tumores perineais malignos em cães: contribuição da tomografia computadorizada para estadiamento e planejamento cirúrgico

The contribution of computed tomography for staging and surgical planning of malignant perineal tumors in dogs is discussed. Five dogs diagnosed with malignant perineal neoplasms underwent to computed tomography (CT) examination. The CT image enabled investigation of cleavage planes between neoplastic lesions and adjacent structures such as the rectum, anus, vagina, urethra and perineal muscles. Accurate assessment regional lymph nodes and adjacent bone structures was also possible. All tumors evaluated in this region presented heterogeneous appearance in pre and postcontrast CT images, but only the anal sac adenocarcinomas presented lymphadenopathy. Computed tomography proved to be a valuable tool for tumor staging and determination of lesion extension and invasion of adjacent tissues, providing significant contributions to clinical and surgical therapeutic planning.(AU)

A contribuição da tomografia computadorizada para estadiamento e planejamento cirúrgico de tumores perineais malignos em cães é discutida. Cinco cães diagnosticados com neoplasias perineais malignas foram submetidos ao exame de tomografia computadorizada (CT). A imagem por TC permitiu a investigação de planos de clivagem entre as lesões neoplásicas e estruturas adjacentes, como o reto, o ânus, a vagina, a uretra e os músculos perineais. A avaliação precisa dos linfonodos regionais e estruturas ósseas adjacentes também foi possível. Todos os tumores avaliados nesta região apresentaram aspecto heterogêneo nas imagens de TC pré e pós-contraste, mas apenas os adenocarcinomas de saco anal apresentaram linfonodopatia. A tomografia computadorizada mostrou ser uma ferramenta valiosa para o estadiamento da neoplasia, determinação da extensão da lesão e invasão de tecidos adjacentes, proporcionando contribuições significativas para o planejamento terapêutico clínico e cirúrgico.(AU)

Prognostic significance of histopathology in canine anal sac gland adenocarcinomas: Preliminary results in a retrospective study of 39 cases.

Metastatic rates and survival times of canine anal sac gland adenocarcinomas (ASGACs) vary among studies, making prognostication difficult. Little is known about the prognostic significance of histopathology of ASGACs. This retrospective study investigated associations between histological features, clinical presentation and outcome for 39 ASGACs. Most tumours were incompletely excised (62%) and had moderate to marked peripheral infiltration (74%). The predominant growth pattern was solid, tubules/rosettes/pseudorosettes and papillary in 49%, 46% and 5% of the cases, respectively. Nuclear pleomorphism was either moderate (77%) or mild (23%). Necrosis and lymphovascular invasion were present in 54% and 10% of the cases, respectively. All histological features except mitotic count and necrosis were associated with nodal metastasis at presentation. A statistically significant poorer outcome was identified for tumours with a solid growth pattern, moderate or marked peripheral infiltration, necrosis and lymphovascular invasion. These results need further validation in a larger cohort of dogs.

Outcome and clinical, pathological, and immunohistochemical factors associated with prognosis for dogs with early-stage anal sac adenocarcinoma treated with surgery alone: 34 cases (2002-2013).

OBJECTIVE To determine survival time and metastatic rate for dogs with early-stage anal sac adenocarcinoma (ASACA) treated with surgery alone and assess whether specific clinical, pathological, or immunohistochemical factors were predictive of outcome for those dogs. DESIGN Retrospective case series. ANIMALS 34 dogs with early-stage, nonmetastatic ASACA that were treated with surgery only. PROCEDURES Medical record databases of 2 referral hospitals were searched to identify dogs examined between 2002 and 2013 that had a diagnosis of nonmetastatic ASACA that was < 3.2 cm at its largest diameter. Only dogs that received surgical treatment alone were included in the study. For each dog, information extracted from the medical record included signalment, clinical and diagnostic test findings, tumor characteristics, and outcome. When available, archived tumor specimens were histologically reviewed and tumor characteristics were described; Ki-67 and E-cadherin expressions were evaluated by use of immunohistochemical methods. Clinical, pathological, and immunohistochemical factors were assessed for associations with survival time and tumor recurrence and metastasis rates. RESULTS Median survival time was 1,237 days. Seven dogs had tumor recurrence and 9 dogs developed metastatic disease at a median of 354 and 589 days, respectively, after primary tumor removal. Cellular pleomorphism was positively associated with development of metastatic disease. No other factors evaluated were associated with outcome. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated dogs with early-stage nonmetastatic ASACA generally had a favorable outcome following surgical removal of the primary tumor alone. Routine rectal examination may be a simple and useful method for detection of dogs with early-stage ASACA.

Malignant collision tumors in two dogs.

CASE DESCRIPTION A 13-year-old Labrador Retriever with a 4-cm-diameter ulcerated perianal mass and a 12-year-old Golden Retriever with a 5-cm-diameter ulcerated caudolateral abdominal mass were brought to a referral oncology practice for evaluation of the dermal masses. Both masses were resected with wide margins without reported postoperative complications. For both dogs, a diagnosis of collision tumor was made. The database of the Veterinary Diagnostic Laboratories at Colorado State University was searched for other examples of collision tumors in dogs. CLINICAL FINDINGS Histologic assessment of the masses revealed collision tumors in both patients. The perianal mass was diagnosed as a perianal gland carcinoma with adjacent hemangiosarcoma. The flank mass was diagnosed as a fibrosarcoma with an adjacent mast cell tumor. The university database search of sample submissions in 2008 through 2014 for the keywords collision, admixed, or adjacent yielded 37 additional cases of dogs with malignant nontesticular collision tumors. TREATMENT AND OUTCOME Both dogs were treated with surgery alone and received no adjunctive treatments. Both tumors were completely excised. There was no evidence of either local tumor recurrence or metastasis in the Labrador Retriever and the Golden Retriever at 1,009 and 433 days after surgery, respectively. CLINICAL RELEVANCE Collision tumors are rare, and there is minimal information regarding treatment recommendations and outcome for animals with collision tumors. On the basis of the 2 cases described in this report, the outcome associated with treatment of collision tumors may be similar to the expected outcome for treatment of any of the individual tumor types in dogs.

Surgical management of primary, metastatic and recurrent anal sac adenocarcinoma in the dog: 52 cases.

OBJECTIVES: To report the outcomes and complications of a cohort of dogs with primary and recurrent anal sac adenocarcinoma managed with surgery as the first-line treatment. To report the use of lymph node cytology for identification of metastatic disease. METHODS: Retrospective review of case records of a single referral centre population of dogs diagnosed with anal sac adenocarcinoma. RESULTS: Fifty-two clinical cases were identified. Altered ultrasonographic appearance of lymph nodes was highly consistent with metastatic disease as assessed by cytology and histopathology. Seven of 58 (12%) perineal surgeries had reported minor complications and seven (12%) others required further surgical intervention. Minor controllable intraoperative bleeding was the only complication noted associated with lymph node extirpation in two of 39 (5%) metastectomy procedures. Six dogs (12%) suffered local recurrence and 22 (42%) developed subsequent or recurrent nodal metastatic disease. From the time of detection of disease recurrence, median additional survival associated with a second surgical intervention was 283 days. CLINICAL SIGNIFICANCE: Coeliotomy for lymph node metastatectomy in dogs with adenocarcinoma of the anal sac has low morbidity and should be considered in patients presenting with evidence of regional metastatic disease both at initial presentation and with recurrent disease.

Outcome in dogs with advanced (stage 3b) anal sac gland carcinoma treated with surgery or hypofractionated radiation therapy.

Stage 3b anal sac gland carcinoma (ASGC) can be life-threatening. A surgical approach is not always possible or may be declined. Dogs with stage 3b ASGC treated with surgery or conformal radiation therapy (RT) with 8 × 3.8 Gy (total dose 30.4 Gy, over 2.5 weeks) were retrospectively evaluated. Patient characteristics, median progression-free interval (PFI) and median survival time (MST) were compared. Twenty-eight dogs were included; 15 underwent surgery, 13 underwent RT. At the time of presentation, 21% showed life-threatening obstipation and 25% showed hypercalcaemia. PFI and MST for surgery cases were 159 days (95% CI: 135-184 days) and 182 days (95% CI: 146-218 days), both significantly lower than for RT cases with 347 days (95% CI: 240-454 days) and 447 days (95% CI: 222-672 days), (P = 0.01, P = 0.019). Surgery as well as RT led to a fast relief of symptoms. PFI and survival of surgical patients were significantly inferior to that of a comparable patient group treated with conformal hypofractionated RT.

Evaluation of adjuvant carboplatin chemotherapy in the management of surgically excised anal sac apocrine gland adenocarcinoma in dogs.

There is no widely accepted standard of care for canine anal sac apocrine gland adenocarcinoma (ASAGAC). Surgery alone is inadequate in many cases, but the benefit of adjuvant chemotherapy is not well established. The primary objective of this retrospective study was to evaluate the role of carboplatin chemotherapy in the post-operative management of ASAGAC. Seventy-four dogs with naturally occurring ASAGAC underwent surgery. Forty-four dogs received adjuvant carboplatin and 30 did not. Median overall survival (OS) was 703 days. Median time to progression (TTP) was 384 days. Only primary tumour size and lymph node metastasis at diagnosis significantly impacted the outcome. Differences in OS and TTP, between the dogs that received adjuvant carboplatin and those that did not, failed to reach statistical significance. Treatment of progressive disease, whilst not limited to chemotherapy, significantly prolonged the survival. This study shows that adjuvant carboplatin chemotherapy is well tolerated and may have a role in the management of dogs with ASAGAC.

Surgical excision of anal sac apocrine gland adenocarcinomas with and without adjunctive chemotherapy in dogs: 42 cases (2005-2011).

Objective-To identify variables associated with prognosis in dogs undergoing surgical excision of anal sac apocrine gland adenocarcinomas (ASACs) with and without adjunctive chemotherapy. Design-Retrospective case series. Animals-42 dogs with ASACs. Procedures-Information on signalment, clinical signs, diagnostic procedures, surgical procedures, adjunctive therapies, survival time, and disease-free interval was obtained from the medical records. Results-Survival time was significantly associated with the presence of sublumbar lymphadenopathy and sublumbar lymph node extirpation, with median survival time significantly shorter for dogs with sublumbar lymphadenopathy (hazard ratio, 2.31) than for those without and for dogs that underwent lymph node extirpation (hazard ratio, 2.31) than for those that did not. Disease-free interval was significantly associated with the presence of sublumbar lymphadenopathy, lymph node extirpation, and administration of platinum-containing chemotherapeutic agents, with median disease-free interval significantly shorter for dogs with sublumbar lymphadenopathy (hazard ratio, 2.47) than for those without, for dogs that underwent lymph node extirpation (hazard ratio, 2.47) than for those that did not, and for dogs that received platinum-containing chemotherapeutic agents (hazard ratio, 2.69) than for those that did not. Survival time and disease-free interval did not differ among groups when dogs were grouped on the basis of histopathologic margins (complete vs marginal vs incomplete excision). Conclusions and Clinical Relevance-Results suggested that in dogs with ASAC undergoing surgical excision, the presence of sublumbar lymphadenopathy and lymph node extirpation were both negative prognostic factors. However, completeness of surgical excision was not associated with survival time or disease-free interval.

Staged marginal contoured and central excision technique in the surgical management of perianal Paget's disease.

BACKGROUND: Extramammary Paget's disease (EMPD) is an adenocarcinoma of the apocrine glands with unknown exact prevalence and obscure etiology. It has been divided into primary EMPD and secondary EMPD, in which an internal malignancy is usually associated. Treatment for primary EMPD usually consists of wide lesion excision with negative margins. Multiple methods have been proposed to obtain free-margin status of the disease. These include visible border lesion excision, punch biopsies, and micrographic and frozen-section surgery, with different results but still high recurrence rates. METHODS: The investigators propose a method consisting of a staged contoured marginal excision using "en face" permanent pathologic analysis preceding the steps of central excision of the lesion and the final reconstruction of the surgical defect. RESULTS: Advantages of this method include adequate margin control allowing final reconstruction and tissue preservation, while minimizing patient discomfort. CONCLUSIONS: The staged contoured marginal and central excision technique offers a new alternative to the armamentarium for surgical oncologists for the management of EMPD in which margin control is imperative for control of recurrence rates.

An overall assessment of circumanal gland adenoma in a terrier mix breed dog.

In September 2012, a 10-year-old, intact male, terrier mix breed dog was evaluated because of multiple, 0.5 to 1.2 cm in diameter, round, intradermal nodules around the anus. It had surgery to excise a firm, painful swelling in the left ventrolateral perianal region and the excision part was observed under light microscopy. The mass spreading in to sub acute was of left hind leg out from the ventro-lateral of anus, 1.2 cm×1 cm/ 0 cm×0.5 cm in size and 125 g in weight. A complete blood cell count, serum biochemistry panel, and urinalysis (cystocentesis sample) were evaluated. Significant laboratory data demonstrated microcytic anemia (hemoglobin of 6.4 mg/dL) and normal coagulation times. No remarkable abnormalities were found in the complete blood count and an ionized calcium of 1.91 mmol/L (reference range, 1.1-1.3 mmol/L) was confirmed hypercalcemia. On cytologic and histopathologic examinations, evaluation of the aspirate revealed a prominent population of round-to-polygonal nucleated cells arranged as cohesive groups with isolated individual cells. A mild degree of anisocytosis and anisokaryosis was observed. In addition, smaller reserve type cells, with darker cytoplasm and a higher nucleocytoplasmic ratio. The adenomas generally retain the lobular architecture, but some may contain focal areas of cellular pleomorphism. These changes may suggest malignant transformation and have led to discordant interpretations, the well-developed stroma surrounding the lobules and hepatoid cells was noted. Ulceration, hemorrhage, necrosis and secondary infection with inflammatory cell infiltrates are common. These cytology and histopathology features are consistent with hepatoid gland adenoma.

Temporally separated bilateral anal sac gland carcinomas in four dogs.

Anal sac gland carcinoma arising from the apocrine secretory epithelium in the anal sac wall, is locally invasive and highly metastatic. The majority of anal sac gland carcinomas are unilateral on presentation, but bilateral tumours have been identified. This case series presents the outcome of four unique cases of unilateral anal sac gland carcinoma which subsequently developed contralateral anal sac gland carcinoma 50 to 390 days after removal of the initial tumour. Median survival was 1035 days after initial diagnosis and 807 days after diagnosis of the second anal sac gland carcinoma.

Evaluation of an anal sac adenocarcinoma tumor in a Spitz dog.

A 9-year-old emasculated male Spitz with tenesmus and constipation had a subcutaneous mass at the left ventral aspect of the anus with history of polyuria and polydipsia. A complete blood cell count, serum biochemistry panel, and urinalysis (cystocentesis sample) were evaluated. Abnormalities in the serum biochemistry panel included a mildly elevated serum cholesterol concentration (7.28 mmol/L; reference interval, 2.70-5.94 mmol/L), increased serum alkaline phosphatase activity (184 U/L; reference interval, 9-90 U/L), alanine transaminase (122 U/L; reference interval, 5-60 U/L) activity and aspartate aminotransferase (80 U/L; reference interval, 5-55 U/L) activity, severe increased total calcium concentration (16.3 mg/dL; reference interval, 8.2-12.4 mg/dL or 9.3-11.4 mg/dL), and decreased total calcium concentration (3.4 mg/dL, reference interval, 2.5-5.6mg/dL). Furthermore, testing revealed an increased intact parathyroid hormone concentration (38.6 pmol/L; reference interval, 3-17 pmol/L). On cytologic and histopathologic examinations, various types of cells were observed. Most of the cells were oval to polygonal and had elliptical or elongate nuclei and a moderate amount of pale to basophilic cytoplasm. The remaining cells had round to oval nuclei and pale to basophilic cytoplasm. Cells of both types were loosely adhered to each other and were arranged in rosette-like structures. Both neoplastic cell types had fine homogenous chromatin and either a small indistinct nucleolus or no visible nucleolus. Mild anisokaryosis and anisocytosis were observed. Histologically, the mass consists of glandular structures formed by cuboidal cells admixed with bundles of spindle cells. Based on location and histologic features, the final diagnosis was adenocarcinoma of the apocrine gland of the anal sac, which should be included as a cytologic differential diagnosis when spindle cells and typical epithelial cells are observed in masses in the region of the anal sac of dogs.

Use of a spiral rectal diaphragm technique to control anal sphincter incontinence in a cat.

CASE DESCRIPTION: A 10-year-old castrated male domestic shorthair cat was examined for a mass involving the right anal sac region. CLINICAL FINDINGS: The mass was diagnosed as a fibrosarcoma, and resulted in progressive tenesmus, requiring repeated resection. TREATMENT AND OUTCOME: Surgical removal of the fibrosarcoma was performed on 4 occasions, including complete resection of the anal sphincter muscles and portions of the rectum. A perineal urethrostomy was required during the third surgical procedure secondary to tumor invasion of the preputial tissues. To reduce involuntary loss of feces, the remaining rectal wall was rotated approximately 225° prior to surgical closure during the second, third, and fourth surgical procedures. This procedure created a natural spiral diaphragm within the rectal lumen. The elastic spiral barrier reduced inadvertent fecal loss and facilitated fecal distention of the terminal portion of the colon, allowing the patient to anticipate the impending passage of feces and to use the litter tray on a daily basis. CLINICAL RELEVANCE: With complete loss of the terminal portion of the rectum and anal sphincter muscles, spiraling the rectum created a deformable threshold barrier to reduce excessive loss of stool secondary to fecal incontinence. On the basis of the positive outcome in this patient, this novel technique may be a useful option to consider for the treatment of cats with loss of anal sphincter function.

Cytologically atypical anal sac adenocarcinoma in a dog.

A 10-year-old intact female Shetland Sheepdog with tenesmus had a subcutaneous mass at the left ventral aspect of the anus. On cytologic examination, 2 types of cells were observed. Most of the cells were oval to polygonal and had elliptical or elongate nuclei and a moderate amount of pale to basophilic cytoplasm. The remaining cells had round to oval nuclei and pale to basophilic cytoplasm. Cells of both types were loosely adhered to each other and were arranged in rosette-like structures. Both neoplastic cell types had fine homogenous chromatin and either a small indistinct nucleolus or no visible nucleolus. Mild anisokaryosis and anisocytosis were observed. Histologically, the mass consists of glandular structures formed by cuboidal cells admixed with bundles of spindle cells. Eosinophilic PAS- and Alcian blue-positive secretory material was found in the center of some glandular structures. Both neoplastic cell types had positive staining with paradoxical concanavalin A and expressed cytokeratin, but not vimentin, S-100, α-smooth muscle actin, or desmin. Based on location and histologic and immunohistochemical features, the final diagnosis was adenocarcinoma of the apocrine gland of the anal sac, which should be included as a cytologic differential diagnosis when spindle cells and typical epithelial cells are observed in masses in the region of the anal sac of dogs.