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Multiple Meningiomas in Cats
PA G E 8
A D VA N C E S
MULTIPLE MENINGIOMAS IN CATS Background Meningiomas are the most common primary intracranial tumor in cats. Since this tumor is slow growing, approximately half of affected cats do not manifest any clinical signs before the tumor is found incidentally. Multiple meningiomas also occur in cats. In humans, multiple meningiomas are usually associated with neurofibromatosis 2 (NF2), an autosomal dominant disorder caused by inactivating mutations of the NF2 tumor suppressor gene. More information is needed to understand multiple meningiomas in cats.
Objectives To describe the clinical signs, magnetic resonance imaging (MRI) findings, surgical procedure, pathological findings, and follow-up in 4 cats with multiple myeloma.
Procedure Medical records of 4 cats diagnosed with multiple meningiomas were reviewed for clinical signs, MRI findings, surgical procedure, pathological findings, and outcome.
Results The affected cats were 3 castrated males and 1 spayed female. All were domestic shorthair indoor cats, ranging in age from 11 to 14 years. In 3 of 4 cats, clinical signs at presentation were suggestive of a focal lesion. Clinical signs included behavioral changes, pacing to 1 side, gait ataxia, and reduced menace reaction. Three of the cats had 2 meningiomas, and 1 had 4 meningiomas. Most of the tumors were supratentorial, 1 arose from the tentorium, and 1 was infratentorial. Presenting signs were present 10 days to 11 months before surgery was performed. Postoperative MRI revealed complete removal of tumor images in 3 cases. The remaining cat had 2 cranial fossa meningiomas and subtotal excisions with a small basal remnant of the ventral part of 1 meningioma lying on the floor of the skull. Ten tumors were found in the 4 cats. Based on histopathologic examinations, 6 tumors were transitional subtype meningiomas, and 4 were meningothelioma-
tous meningiomas. In each cat, the multiple meningiomas were all assigned to the same histopathological group. Presenting signs resolved by follow-up examination at 4 weeks after surgery in 2 cats. Surgically induced or exacerbated neurological deficits in 2 cats completely, or nearly completely, resolved within 8 weeks of surgery. All patients were still alive 12 to 21 months after surgery with no clinical signs of recurrence.
Author Conclusion Surgical treatment of multiple meningiomas in cats is possible and has a good outcome. The presence of multiple tumors does not significantly influence the postsurgical prognosis.
Inclusions One figure, 2 tables, 22 references.
Editor Annotation Meningioma is the most common primary intracranial neoplasm of the cat. Surgical removal is a very effective treatment for the slowly progressive disease, with previous studies reporting average survival times of approximately 2 years after resection of single lesion. Although it only describes 4 cats, this study is worth noting for 2 reasons. First, it reiterates the point that many feline meningiomas are small enough to be clinically silent. Multiple lesions were suspected prior to MRI in only 1 of the cats described here, showing that a large tumor may be accompanied by 1 or more smaller lesions, despite neurolocalization to a single site. Second and most important is that veterinarians must not assume that surgery will be ineffective, even when multiple meningiomas are identified. The 4 cats in this study were all still alive 12 to 24 months after craniotomy. Histopathologic examination results were strongly suggestive of unrelated primary tumors in these animals, and surgical resection of each of these lesions should therefore be associated with similar long-term disease control. Veterinarians should always recommend full neurologic evaluation with cross-sectional imaging (CT scan or MRI) to the owners of aged cats with recent onset of neurologic signs. Based on the results of this study, committed owners should still be encouraged to pursue referral for surgical resection, even when evaluation suggests
Journals Monitored • American Journal of Veterinary Research • Australian Veterinary Journal • Australian Veterinary Practitioner • Avian Diseases • British Veterinary Journal • Canadian Journal of Veterinary Research • Canadian Veterinary Journal • Journal of Avian Medicine and Surgery • Journal of the American Animal Hospital Association • Journal of the American Veterinary Medical Association • Journal of Small Animal Practice • Journal of Small Exotic Animal Medicine • Journal of Veterinary Dentistry • Journal of Veterinary Internal Medicine • Journal of Veterinary Pharmacology and Therapeutics • Journal of Zoo and Wildlife Medicine • New Zealand Veterinary Journal • Research in Veterinary Science • Veterinary and Comparative Orthopaedics and Traumatology • Veterinary Dermatology • Veterinary Immunology and Immunopathology • Veterinary Pathology • Veterinary Radiology & Ultrasound • Veterinary Record • Veterinary Research Communications • Veterinary Surgery ... and more than 20 others
that more than 1 meningioma is present. (GEM) Forterre F, Tomek A, Konar M, et al. Multiple meningiomas: clinical, radiological, surgical, and pathological findings with outcome in four cats. J Feline Med Surg 2007;9:36-43.
A D VA N C E S
MULTIPLE MENINGIOMAS IN CATS Background Meningiomas are the most common primary intracranial tumor in cats. Since this tumor is slow growing, approximately half of affected cats do not manifest any clinical signs before the tumor is found incidentally. Multiple meningiomas also occur in cats. In humans, multiple meningiomas are usually associated with neurofibromatosis 2 (NF2), an autosomal dominant disorder caused by inactivating mutations of the NF2 tumor suppressor gene. More information is needed to understand multiple meningiomas in cats.
Objectives To describe the clinical signs, magnetic resonance imaging (MRI) findings, surgical procedure, pathological findings, and follow-up in 4 cats with multiple myeloma.
Procedure Medical records of 4 cats diagnosed with multiple meningiomas were reviewed for clinical signs, MRI findings, surgical procedure, pathological findings, and outcome.
Results The affected cats were 3 castrated males and 1 spayed female. All were domestic shorthair indoor cats, ranging in age from 11 to 14 years. In 3 of 4 cats, clinical signs at presentation were suggestive of a focal lesion. Clinical signs included behavioral changes, pacing to 1 side, gait ataxia, and reduced menace reaction. Three of the cats had 2 meningiomas, and 1 had 4 meningiomas. Most of the tumors were supratentorial, 1 arose from the tentorium, and 1 was infratentorial. Presenting signs were present 10 days to 11 months before surgery was performed. Postoperative MRI revealed complete removal of tumor images in 3 cases. The remaining cat had 2 cranial fossa meningiomas and subtotal excisions with a small basal remnant of the ventral part of 1 meningioma lying on the floor of the skull. Ten tumors were found in the 4 cats. Based on histopathologic examinations, 6 tumors were transitional subtype meningiomas, and 4 were meningothelioma-
tous meningiomas. In each cat, the multiple meningiomas were all assigned to the same histopathological group. Presenting signs resolved by follow-up examination at 4 weeks after surgery in 2 cats. Surgically induced or exacerbated neurological deficits in 2 cats completely, or nearly completely, resolved within 8 weeks of surgery. All patients were still alive 12 to 21 months after surgery with no clinical signs of recurrence.
Author Conclusion Surgical treatment of multiple meningiomas in cats is possible and has a good outcome. The presence of multiple tumors does not significantly influence the postsurgical prognosis.
Inclusions One figure, 2 tables, 22 references.
Editor Annotation Meningioma is the most common primary intracranial neoplasm of the cat. Surgical removal is a very effective treatment for the slowly progressive disease, with previous studies reporting average survival times of approximately 2 years after resection of single lesion. Although it only describes 4 cats, this study is worth noting for 2 reasons. First, it reiterates the point that many feline meningiomas are small enough to be clinically silent. Multiple lesions were suspected prior to MRI in only 1 of the cats described here, showing that a large tumor may be accompanied by 1 or more smaller lesions, despite neurolocalization to a single site. Second and most important is that veterinarians must not assume that surgery will be ineffective, even when multiple meningiomas are identified. The 4 cats in this study were all still alive 12 to 24 months after craniotomy. Histopathologic examination results were strongly suggestive of unrelated primary tumors in these animals, and surgical resection of each of these lesions should therefore be associated with similar long-term disease control. Veterinarians should always recommend full neurologic evaluation with cross-sectional imaging (CT scan or MRI) to the owners of aged cats with recent onset of neurologic signs. Based on the results of this study, committed owners should still be encouraged to pursue referral for surgical resection, even when evaluation suggests
Journals Monitored • American Journal of Veterinary Research • Australian Veterinary Journal • Australian Veterinary Practitioner • Avian Diseases • British Veterinary Journal • Canadian Journal of Veterinary Research • Canadian Veterinary Journal • Journal of Avian Medicine and Surgery • Journal of the American Animal Hospital Association • Journal of the American Veterinary Medical Association • Journal of Small Animal Practice • Journal of Small Exotic Animal Medicine • Journal of Veterinary Dentistry • Journal of Veterinary Internal Medicine • Journal of Veterinary Pharmacology and Therapeutics • Journal of Zoo and Wildlife Medicine • New Zealand Veterinary Journal • Research in Veterinary Science • Veterinary and Comparative Orthopaedics and Traumatology • Veterinary Dermatology • Veterinary Immunology and Immunopathology • Veterinary Pathology • Veterinary Radiology & Ultrasound • Veterinary Record • Veterinary Research Communications • Veterinary Surgery ... and more than 20 others
that more than 1 meningioma is present. (GEM) Forterre F, Tomek A, Konar M, et al. Multiple meningiomas: clinical, radiological, surgical, and pathological findings with outcome in four cats. J Feline Med Surg 2007;9:36-43.