Periocular cutaneous mast cell tumors in cats: evaluation of surgical excision (33 cases)

Objective  To describe feline periocular cutaneous mast cell tumor (CMCT) clinical features, rates of local tumor recurrence and metastases, and cat survival time following surgical excision.
Animals studied  Thirty-three cats with periocular CMCTs.
Procedures  Medical records of cats diagnosed with periocular CMCTs were reviewed; cats were included if CMCTs were surgically excised and the diagnosis confirmed by histopathology. The appearance, size, location and histopathology findings of CMCTs were recorded. Rates of local recurrence, metastasis, and survival time following surgical excision were collected when available.
Results  All periocular CMCTs were restricted to the eyelids. In addition to surgical excision, three cats were treated with adjunctive therapy (strontium-90 irradiation or cryotherapy) intraoperatively. Local tumor control was achieved in 22/23 cats with a minimum follow-up of 30 days (median follow-up time of 711 days); one cat developed disseminated CMCTs but no local recurrence. Cats with periocular CMCTs had a median survival time of 945 days. Metastatic disease involving peripheral lymph nodes or abdominal viscera was not detected in any cat at any time during the study. All periocular CMCTs were classified as low-grade based on histopathology, and complete excision was achieved in approximately 50% of cases.
Conclusions  Surgical excision of periocular CMCTs in cats is an effective treatment option with rare local recurrence and metastases, even following incomplete surgical excision.     

Radiation therapy for long-term control of odontogenic tumours and epulis in three cats.

Orthovoltage radiation was used to treat odontogenic tumours in three cats following incomplete surgical resection. Cats received a total radiation dose of 48-52 Gy over a period of 26-29 days. Acute toxicities were mild, consisting of hair loss within the radiation field in all cats, and mild mucositis in one cat. All cats had long-term (>35 months) control of their tumour, and two cats are still alive without recurrence of tumour 60 and 39 months, respectively, after completing treatment. Radiation therapy should be considered to be an adjuvant to incomplete surgery in cats with odontogenic neoplasms or epulides.     

Treatment and outcome of four cats with apocrine gland carcinoma of the anal sac and review of the literature

Anal sac adenocarcinoma is uncommon in cats. We report the outcome of multi-modality therapy in two cats (surgery, definitive radiotherapy and systemic chemotherapy) and surgery alone in two cats. All received surgical excision of the primary tumour followed by radiotherapy and carboplatin chemotherapy in two cases. Both cats that underwent multimodal therapy developed distant metastatic disease and one developed recurrence of the primary tumour. One cat that underwent surgery alone with incomplete margins also developed rapid recurrence. Overall survival times were 89, 161 and 169 days. One cat that had complete surgical excision is still alive without recurrence 425 days postoperatively. Whilst the role of radiation in the local control of this disease is yet to be defined, clearly a more effective systemic therapy is required before such aggressive local treatment can be routinely recommended.     

Hemangiosarcoma in the cat: retrospective evaluation of 31 surgical cases

Hemangiosarcoma was diagnosed in 31 cats. Diagnosis was confirmed by surgical biopsy. Locations of the primary tumors were the abdominal cavity (15 cats), sc tissue (13 cats), thoracic cavity (2 cats), and nasal cavity (1 cat). Nine (60%) of the 15 cats with abdominal hemangiosarcoma had extrathoracic evidence of metastasis: this was not found in the other cats. Of the cats with tumors located in the sc tissue, 6 of 10 (60%) evaluated on a long-term basis had local recurrence of the tumor. Eleven cats were not available for follow-up evaluation, 3 cats were euthanatized at the time of surgery, and 2 others were euthanatized within the first postoperative week subsequent to histologic diagnosis of hemangiosarcoma. Of the remaining 15 cats, 4 with abdominal hemangiosarcoma and 5 with hemangiosarcoma of the sc tissue died at means of 22 and 44 weeks, respectively.     

Feline periocular peripheral nerve sheath tumor: a case series

The objective of this retrospective study was to describe signalment, clinical presentation, surgical treatment, outcome, histopathologic, and immunohistochemical characteristics of periocular peripheral nerve sheath tumor in a series of cats. Six cats with a histologic diagnosis of peripheral nerve sheath tumor of the eyelid and/or conjunctiva were identified from 3997 feline ocular histopathologic submissions to the Comparative Ocular Pathology Laboratory of Wisconsin between 1976 and 2002. Medical records were reviewed and data were collected for signalment, eye affected, location, duration, and history of tumor recurrence. Ancillary diagnostic tests, surgical approach, and histopathology were also described. Special stains and immunohistochemistry panels were performed on the tissue. Follow-up information was obtained through telecommunications with the owner and local veterinarian. The mean age of the cats was 8 years (range: 5-15 years). There was an equal distribution of males and females. Breeds represented were two Domestic Long-haired (DLH) cats, three Domestic Short-haired (DSH) cats, and one Manx. The right eye was affected in four cats and the left eye in two cats. The superior eyelid was affected in four cats, the superior conjunctiva in two cats, and the inferior eyelid in one cat. All of the cats that underwent surgical excision, cryoablation, or laser ablation had an average of three recurrences of the tumor. Four of six cats undergoing wide excision with enucleation, exenteration or rhomboid flap had no recurrence of the tumor. Histomorphologically, all of the tumors were of spindle cell type with five of six tumors showing histologic features of Antoni type B tissue. All six tumors stained positive for vimentin. Five of six tumors stained positive for S-100 and laminin. All six tumors were negative for smooth muscle actin. Definitive histologic diagnoses of spindle cell tumors can be difficult. The presence of Antoni A and B histologic patterns as well as immunohistochemical reactivity for vimentin, S-100, and laminin suggest a diagnosis of peripheral nerve sheath tumor. Our findings suggest that local aggressive recurrence is common and that wide surgical excision combined with enucleation or exenteration may be indicated.     

Surgical Excision of Soft Tissue Fibrosarcomas in Cats

Objective — The purpose of this study was to determine the tumor-free interval and survival times of cats who had one (group 1) or more (group 2) surgeries, or surgery and radiation therapy (RTH) (group 3) for treatment of soft tissue fibrosarcomas (FSA).
Study Design — Retrospective study.
Animals or Sample Population — 45 client-owned cats.
Methods — Medical records of cats with soft tissue FSA were examined. Vaccination and feline leukemia virus (FeLV) status, age, sex, breed, tumor location, number of surgeries, completeness of excision, and histopathological grade were evaluated to correlate with tumor-free interval and survival periods.
Results — Overall median tumor-free interval and survival times were 10 and 11.5 (range, 1 to 40) months. Median tumor-free interval and survival times were more than 16 months each in group 1, more than 5 and 13 months in group 2, and 4.5 and 9 months in group 3. Age, sex, breed, vaccination or FeLV status, tumor location, or histopathological grade did not affect median tumor-free interval or survival times ( P <.05). Cats with complete excisions had significantly longer median tumor-free interval (>16 versus 4 months) and survival time (>16 versus 9 months) than those with incomplete excisions ( P =.008). Radiation therapy did not seem to extend tumor-free interval and survival times ( P =.013). However, most group 3 cats had incomplete surgical excisions, resulting in recurrent or progressive disease.
Conclusions — Complete surgical excision of FSA in cats is possible and can be curative.
Clinical Relevance — Aggressive surgical excision with wide margins appears to contribute to extended tumor-free interval and survival times in cats with soft tissue FSA. Controlled prospective studies are needed to determine the efficacy of RTH in treatment.     

Dermatophytic pseudomycetomas in four cats

The aim of this retrospective study was to describe the clinical characteristics and treatment of four cats with dermatophytic pseudomycetoma. Four Persian cats, one female and three males, with age ranging from 1.4 to 5 years, were diagnosed with dermatophytic pseudomycetoma by histological examination and fungal culture. Wood's lamp examination revealed positive fluorescence of hairs in all four cats. Characteristic skin lesions consisted of multifocal, raised, firm and nodular to dome-shaped lesions varying in size from 1 to 8 cm in diameter, with ulcers or fistulas in some of the lesions. One cat was treated and cured with 3 months of oral itraconazole; lesions completely regressed, and at the time of writing there has been no recurrence. One cat was treated with surgical excision alone, and recurrence of lesions occurred after a disease-free interval of 15 months. Two cats were treated with surgical excision and systemic itraconazole therapy. Itraconazole therapy was started 1-2 months before surgery and continued for 3 months after surgery. Surgical margins were wide in both cats, and underlying adipose tissue and/or deeper fascia was removed. One cat relapsed, but had a disease-free interval of 18 months. The other cat has been disease free for 32 months. This case series suggests that aggressive, wide surgical excision and concurrent oral itraconazole are highly beneficial in treating dermatophytic pseudomycetoma in cats.     

Subcutaneous abscesses and arthritis caused by a probable bacterial L-form in cats

Three cats in one household developed pyogenic subcutaneous abscesses and arthritis over a period of 9.5 months. Despite vigorous surgical and antibiotic treatment, the infections in each of these cats continued to spread locally and hematogenously to involve other joints and subcutaneous sites. Although the infections did not respond to modern broad-spectrum antibiotics, they were susceptible to tetracycline. In spite of a favorable response to tetracycline, all 3 cats were euthanatized. A causative agent could not be identified by microbiologic culture of tissues obtained prior to death and at necropsy, or with special tissue stains. The infection was transmitted experimentally by sc inoculation with cell-free material from one of the naturally infected cats to a specific-pathogen-free cat. A tissue extract from the experimentally infected cat was, in turn, infectious for another specific-pathogen-free cat. The experimentally induced lesion was a rapidly enlarging necrotizing and pyogenic cellulitis and panniculitis, with no demonstrable causative agent by special tissue stains or microbiologic culture. A probable bacterial L-form was visualized in affected tissues of the experimentally infected cats and propagated in special L-form broth. Like the natural disease, infection in experimentally inoculated cats was progressive in nature, but could be treated successfully with tetracycline.     

Evaluation of progesterone and estrogen receptor expression in 15 meningiomas of dogs and cats

OBJECTIVE: To evaluate progesterone and estrogen receptor expression in meningiomas of the CNS in dogs and cats. ANIMAL: 8 dogs (1 of which was treated with gestrinone) and 5 cats with intracranial meningiomas and 2 dogs with spinal cord meningiomas; tissue samples were also obtained from 1 clinically normal dog and 1 clinically normal cat. PROCEDURE: Meningioma tissue was obtained during surgery or at necropsy; samples were processed for histologic classification and immunohistochemical evaluation of the proportion of tumor cells with progesterone and estrogen receptors. Correlation among receptor expression, tumor grade, and histologic subtypes was determined. RESULT: Several histologic subtypes of intracranial meningiomas were detected among tissue samples. In the cats, all intracranial meningiomas were benign. Progesterone receptor immunoreactivity was detected in 14 of 15 meningiomas. Progesterone receptor expression was identified in > 80% of cells in 8 intracranial meningiomas (4 dogs and 4 cats) and 2 spinal cord meningiomas. In samples of malignant transitional and granular cell meningiomas in dogs, progesterone receptors were detected in 32 and 4.8% of cells respectively. In 1 cat, 38% of tumor cells had progesterone receptors. In a dog treated with gestrinone, no progesterone receptors were detected in the intracranial meningioma. Estrogen receptors were only detected in the tumor of 1 dog. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicate a high proportion of progesterone receptors in cells of meningiomas of the CNS in dogs and cats. Antiprogesterone treatment may have a role in the treatment of unresectable or recurrent meningiomas in dogs and cats.     

Thyroidectomy in the cat

Thyroidectomy in cats is most commonly indicated to treat hyperthyroidism because of adenomatous hyperplasia of the thyroid glands. Preoperative stabilization of the hyperthyroid cat with antithyroid drugs is preferred to minimize anesthetic and surgical complications. Multiple surgical techniques for thyroidectomy have been reported, and results of surgery and complications differ between techniques. The extracapsular technique offers the most complete removal of abnormal thyroid tissue, while still being associated with a low incidence of postoperative hypoparathyroidism. Important postoperative considerations are to carefully monitor serum calcium concentrations and treat hypocalcemia if necessary, and to monitor the cat for evidence of relapse of hyperthyroidism.     

Mutations in the 3c and 7b genes of feline coronavirus in spontaneously affected FIP cats

Feline infectious peritonitis (FIP) is the most frequent lethal infectious disease in cats. However, understanding of FIP pathogenesis is still incomplete. Mutations in the ORF 3c/ORF 7b genes are proposed to play a role in the occurrence of the fatal FIPV biotype. Here, we investigated 282 tissue specimens from 28 cats that succumbed to FIP. Within one cat, viral sequences from different organs were similar or identical, whereas greater discrepancies were found comparing sequences from various cats. Eleven of the cats exhibited deletions in the 3c gene, resulting in truncated amino acid sequences. The 7b gene was affected by deletions only in one cat. In three of the FIP cats, coronavirus isolates with both intact 3c genes as well as 7b genes of full length could also be detected. Thus, deletions or stop codons in the 3c sequence seem to be a frequent but not compelling feature of FIPVs.     

Clinical presentation,diagnosis, treatment and outcome of spinal epidural empyema in four cats (2010 to 2016)

This case series reviews previous publications and reports four feline spinal epidural empyema cases that presented with non-ambulatory thoracolumbar myelopathy. Two cats underwent myelography and two MRI. Bacteria were obtained in three cases, in two from epidural abscesses and from a tail base wound in one; histopathological examination of epidural tissue showed pyogranulomatous changes in the remaining cat. Three cats were treated by surgical decompression plus antimicrobial therapy and one cat was treated medically. All cats showed satisfactory improvement following treatment over a follow-up period of 3 months. Spinal epidural empyema is a rare condition but all cats in this series had favourable outcomes.     

Nasopharyngeal and Middle Ear Polypoid Masses in Five Cats

Five cats with nasopharyngeal and middle ear polypoid masses are presented. The clinical signs included nasal discharge, sneezing, labored breathing, swallowing difficulty, and voice changes. Diagnosis was made by radiography and oropharyngeal examination. Surgical mangement consisted of local nasopharyngeal polyp resection in all cats, combined with ventral bulla osteotomy in three cats. Recurrence resulted in two of the five cats in which incomplete nasopharyngeal removal was performed initially, but not in the cats treated by bulla osteotomy. Four of the five cats were clinically normal 7 to 14 (median 13) months following surgery. The fifth cat had mild upper respiratory airway noise at 7 months. The histopathologic diagnosis of these growths was inflammatory tissue.     

Dysplasia of the tricuspid valve in the dog and cat.

Dysplasia of the tricuspid valve in 14 dogs and 13 cats was studied. The clinical, electrocardiographic, radiographic, hemodynamic, angiocardiographic, and pathologic findings were reviewed in each species. Alterations of the tricuspid valve complex included long, thick septal leaflets adhered to the septum; absent or short, stout fused chordae tendineae; hypertrophic fused papillary muscles; insertion of papillary muscles directly into the lateral leaflets; incomplete development of the valvular tissue; and enlargement of the right atrium and ventricle. Additional intracardiac anomalies included malformation of the mitral valve complex (5 dogs and 3 cats), ventricular septal defect (3 dogs and 3 cats), pulmonary stenosis (1 dog and 1 cat), aortic stenosis (1 dog and 1 cat), and persistent left cranial vena cava (1 dog).     

Appendicular arterial tumor embolization in two cats with pulmonary carcinoma

A 13-year-old neutered male Persian cat and an 11-year-old neutered female Persian cat were examined because of an acute onset of lameness. In both cats, conscious proprioception and reflexes were diminished in the affected limb. In 1 cat, no blood flow was detected in the left brachial artery with a Doppler ultrasonic flow detector, whereas blood flow in the right brachial artery was easily documented. In the other cat, the right femoral pulse was not palpable. Neither cat had any echocardiographic evidence of cardiac disease. In both cats, treatment was primarily supportive. One cat died, and the other was euthanatized. At necropsy, lung lobe consolidation was seen. Microscopically, there was multifocal infiltration of the lung parenchyma with cuboidal to columnar neoplastic epithelial cells. Neoplastic epithelial cells of similar morphology were identified in nodular masses in sections of muscle, and intravascular tumor emboli were identified obliterating small and large arterioles. Immunohistochemical staining of pulmonary and muscular tissue for pan-cytokeratin antigen revealed intense cytoplasmic staining of neoplastic cells. Staining for factor VIII-related antigen confirmed that clusters of neoplastic cells represented intravascular emboli. Clinical signs in the cats were attributed to arterial occlusion by tumor emboli.     

Radical Lateral Body-Wall Resection for Fibrosarcoma With Reconstruction Using Polypropylene Mesh and a Caudal Superficial Epigastric Axial Pattern Flap: A Prospective Clinical Study of the Technique and Results in 6 Cats

OBJECTIVE: To describe and evaluate a technique for radical resection of the lateral body wall for treatment of fibrosarcoma with reconstruction using polypropylene mesh and a caudal superficial epigastric axial pattern flap in cats. STUDY DESIGN: Prospective, clinical study. ANIMALS OR SAMPLE POPULATION: Six client-owned cats with fibrosarcoma. METHODS: Six cats with histologically confirmed fibrosarcoma of the lateral body wall were staged using radiography and/or computer tomography scanning. Preoperative radiotherapy was used in 3 cats. All cats had the lateral abdominal wall resected and reconstructed with polypropylene mesh. A caudal superficial epigastric flap was mobilized and rotated to close the skin deficit. The animals were evaluated after surgery for wound complications, tumor recurrence, and metastasis. Outcome was assessed by patient examination and client consultation. RESULTS: Minor dehiscence of the skin flaps occurred in 2 cats, and 1 other cat was successfully resuscitated from respiratory and cardiac arrest after surgery. All tissue specimens were tumor-free at the surgical margins. Follow-up times ranged from 12 to 21 months, with a mean time of 17.2 months. None of the cats had evidence of local tumor recurrence or metastasis; outcome was judged good to excellent in all cats. CONCLUSIONS AND CLINICAL RELEVANCE: Radical lateral body-wall resection and reconstruction is an effective technique for achieving local tumor control with acceptable patient morbidity. Further studies are needed to assess whether the technique will result in improved tumor-free intervals and survival times.     

En Bloc Ovariohysterectomy as a Treatment for Dystocia in Dogs and Cats

En bloc ovariohysterectomy, a technique that involves ovariohysterectomy before hysterotomy and removal of the neonates, was performed on 63 animals (37 dogs and 26 cats). Intraoperative complications were limited to 1 cat that bled excessively during surgery and was later found to have a clotting disorder. Postoperative complications included anemia that required blood transfusion in 3 cats, uroperitoneum in 1 dog, and death in 1 cat. The rate of neonatal survival (75% for dogs and 42% for cats) was similar to that documented by previous studies of medical and surgical management of dystocia. We concluded that en bloc ovariohysterectomy is a safe and effective alternative to cesarean section for surgical treatment of dystocia in dogs and cats.     

Surgical treatment of a meningoencephalocele in a cat

Objective: To report the clinical signs, imaging findings and surgical treatment of a meningoencephalocele in a cat. Study Design: Case report. Animal: Domestic shorthaired cat, 4 months old. Methods: A parietal meningoencephalocele was identified and characterized by magnetic resonance and computed tomography (CT) imaging. The abnormal tissue was excised and submitted for histopathology, and the meningeal and skull defects were reconstructed. Results: The cat made a full recovery and the episodes of aggression, restlessness and apparent discomfort that occurred before surgery ceased after surgical treatment. The cat was clinically normal 1 year postoperatively. Conclusion: Surgical management of meningoencephalocele in cats may be a viable treatment option.     

Malignant fibrous histiocytoma in a cat

A large proliferative soft tissue mass found on the forelimb of an adult cat was identified as a malignant fibrous histiocytoma through cytologic and histologic examinations. This is a rare tumor of mesenchymal cell origin, which has been previously reported in cats, dogs, horses, and human beings. In this cat metastasis to the local lymph node was found.     

RADIOTHERAPY WITH AND WITHOUT CHEMOTHERAPY FOR LOCALIZED LYMPHOMA IN 10 CATS

A retrospective study was undertaken to determine the efficacy of radiotherapy with and without chemotherapy for treatment of localized lymphoma in 10 cats. Tumor location included nasal cavity (3 cats), retrobulbar area (3 cats), mediastinum (1 cat), subcutaneous tissue (1 cat), maxilla (1 cat) and mandible (1 cat). Six cats were treated with radiation alone and 4 cats also received chemotherapy during and/or after radiotherapy. Complete remission was achieved locally in 8 of 10 cats, whereas 2 cats had partial remission. Five of the 6 cats treated with radiotherapy alone achieved complete remission. Overall mean and median remission times for the 8 cats with complete remission were 123 weeks and 114 weeks, respectively (range 4 to 277 weeks). Three of the 8 cats have been in complete remission for more than 131 weeks and are still alive. Three cats achieving complete local remission developed lymphoma outside the radiation field. One cat had recurrence at the site of irradiation. Results of the retrospective study suggest that radiotherapy with and without chemotherapy may be effective for the treatment of localized lymphoma in the cat.