Alexander

Benoit

Cordy

Corzo-Menendez

Kloc

Martin-Vaquero

Middleton

Morris

Njoku

Padgett

Parkes

Sanders

Smith

Stalin

Summers

Wells

Wilson

Zaki

English

Taylor-Brown, F E

Lamb, C R

Martineau, H

Muir, C

Beltran, E

RVC Repository (Royal Veterinary College)

  RVC OPEN ACCESS REPOSITORY – COPYRIGHT NOTICE  This is the peer reviewed version of the following article: Taylor-Brown, F. E., Lamb, C. R., Martineau, H., Muir, C. and Beltran, E. (2016), IMAGING DIAGNOSIS—IMAGING AND HISTOPATHOLOGIC CHARACTERISTICS OF A VERTEBRAL HAMARTOMA IN A CAT. Vet Radiol Ultrasound. doi:10.1111/vru.12454 This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving. The full details of the published version of the article are as follows:  TITLE: Imaging diagnosis—imaging and histopathologic characteristics of a vertebral hamartoma in a cat AUTHORS: Taylor-Brown, F. E., Lamb, C. R., Martineau, H., Muir, C. and Beltran, E. JOURNAL TITLE: Veterinary Radiology & Ultrasound PUBLISHER: Wiley PUBLICATION DATE: November 2016 (online) DOI: 10.1111/vru.12454  1 IMAGING DIAGNOSIS – IMAGING AND HISTOPATHOLOGIC 1 CHARACTERISTICS OF A VERTEBRAL HAMARTOMA IN A CAT 2  3 Frances E Taylor-Brown, Christopher R. Lamb, Henny Martineau, Clare Muir, Elsa Beltran 4 Department of Clinical Science and Services (Taylor-Brown, Lamb, Beltran), and Department of 5 Pathology and Pathogen Biology (Martineau, Muir), The Royal Veterinary College, Hawkshead 6 Lane, North Mymms, Hertfordshire AL9 7TA, UK. 7  8 Corresponding author: Elsa Beltran ebeltran@rvc.ac.uk  9  10 Key Words: cat, hamartoma, paraparesis, spinal disease 11 Running head: Vertebral hamartoma in a cat  12  2 Abstract 13 A 9-month-old domestic shorthair cat had progressive ambulatory paraparesis, proprioceptive 14 ataxia, and thoracolumbar hyperesthesia. An extradural mass lesion affecting the left pedicle and 15 lamina of the second lumbar vertebra (L2) causing marked spinal cord impingement was 16 identified in magnetic resonance (MR) images. The mass was predominantly calcified in 17 computed tomographic images. A hemilaminectomy was performed to resect the mass. Clinical 18 signs were greatly improved at 6-month follow-up. The histopathologic diagnosis was vascular 19 hamartoma. To our knowledge, this is the first report describing the MR characteristics of a 20 vascular hamartoma associated with the vertebral column.   21  3 Signalment, history, and clinical findings 22 A 9-month-old male neutered domestic short hair cat had progressive pelvic limb proprioceptive 23 ataxia, ambulatory paraparesis and thoracolumbar hyperesthesia. The cat had an 8-week history 24 of vocalization, aggression on handling, and signs of pain on palpation of the abdomen and 25 thoracolumbar spine. No other clinical signs were reported prior to referral. Treatment with 26 meloxicam initially improved the clinical signs, but 4 weeks prior to referral the cat developed 27 progressive proprioceptive ataxia and paresis of the pelvic limbs.  28 When referred, the cat had normal vital signs. The cat had ambulatory paraparesis with marked 29 proprioceptive ataxia in the pelvic limbs and repeatable signs of thoracolumbar hyperesthesia on 30 direct palpation. There was voluntary urinary and fecal continence. The cat’s demeanor 31 prevented full physical and neurological examination, including assessment of pelvic limb spinal 32 reflexes. The tentative neuroanatomical localization was T3-S3. Hematology, serum 33 biochemistry and urinalysis were within normal ranges. 34  35 Imaging, diagnosis and outcome 36 The cat was anesthetized in dorsal recumbency for MR imaging of the thoracolumbar vertebral 37 column using a 1.5 Tesla scanner (Intera, Philips Medical Systems, Surrey, UK) and a spinal 38 coil. Transverse and sagittal T1-weighted (TR 400–500 ms, TE 8 ms) and T2-weighted (TR 39 3000–3144 ms, TE 120 ms) images were acquired with slice thickness 1.8–2.5 and 0.25mm 40 interspace. T1-weighted images were acquired before and immediately after manual intravenous 41 injection of gadolinium-containing contrast medium (0.1 ml/kg gadoterate meglumine, Dotarem, 42 Guerbet, Milton Keynes, UK). A solitary focal, extradural mass was identified continuous with 43  4 the left pedicle and lamina of the L2 vertebra, extending into the vertebral canal and causing 44 marked spinal cord impingement (Fig. 1). When compared to normal spinal cord parenchyma the 45 periphery of the lesion was predominantly isointense to hyperintense on T2-weighted images and 46 hypointense on T1-weighted images. The center of the lesion was more heterogeneous in 47 appearance and appeared hypointense compared to normal spinal cord parenchyma on T2- and 48 T1-weighted images. At the interface between the lesion and the spinal cord at the cranial and 49 caudal aspects there is a well-demarcated area of tissue that is T2-weighted hyperintense and T1-50 weighted iso-hyperintense compared to normal spinal cord parenchyma. Postcontrast images 51 revealed moderate, homogenous contrast enhancement of the central zone of the mass and 52 marked contrast enhancement along its interface with the vertebral canal. The spinal cord was 53 markedly displaced to the right and flattened by the mass. No other spinal lesions were observed. 54 In order to further characterize the lesion, a CT scan was performed of the entire vertebral 55 column, thorax, and abdomen using a 16-slice helical scanner (MX 8000 IDT, Philips Medical 56 Systems). Images were obtained using helical acquisition, 120 kVp, 140 mAs, and 2.0 mm slice 57 thickness. The mass lesion associated with the left pedicle and lamina of the L2 vertebra was 58 densely calcified (mean 1130 HU) with an irregular inner border, and occupied the vertebral 59 canal without any increase in the outer dimensions of the vertebrae (Fig. 2). No other lesions 60 were observed. 61 Based on its imaging features and the clinical presentation, the most likely differential diagnoses 62 were considered to be neoplastic (e.g. fibrosarcoma, fibroma, osteosarcoma, chondroma), 63 infectious/inflammatory (osteomyelitis), or traumatic (excessive callous formation following 64 previous trauma). 65  5 A left-sided hemilaminectomy at L1-L2 was performed. The outer cortical bone had a normal 66 gross appearance but the vertebral cancellous bone of L2 was thickened with an enlarged porous 67 structure (Fig 3A). There inner cortical bone of the pedicle was poorly differentiated from the 68 cancellous bone and there was associated hemorrhagic soft tissue material on its medial aspect. 69 The dura was exposed to relieve the spinal cord compression (Fig 3B). Samples of the abnormal 70 bone were submitted for histopathologic examination and for bacterial culture. Post-operative 71 medications included methadone (0.1-0.2 mg/kg IV every 4 hours for one day; Comfortan, 72 Dechra, Shropshire, UK), buprenorphine (0.01-0.02 mg/kg for two days following methadone; 73 Buprecare, Animalcare, North Yorkshire, UK), meloxicam (0.05 mg/kg orally once daily for 10 74 days; Metacam, Boheringer Ingelheim, Berkshire, UK) and gabapentin (7 mg/kg orally twice 75 daily for 14 days; Gabapentin Medreich PLC, Feltham, UK). The cat recovered well from 76 surgery and had reduced signs of spinal pain when discharged four days later, although the 77 paraparesis and proprioceptive ataxia in the pelvic limbs were unchanged. Voluntary urinary and 78 fecal continence were retained after surgery.  79 Tissue samples for histopathological analysis were fixed in 10% neutral buffered formalin, 80 processed routinely and embedded in paraffin wax. Sections (4 μm) were stained with 81 hematoxylin and eosin (HE). Present within the medullary cavities and extending to the 82 periosteum are variably dense proliferations of endothelial cells forming small caliber blood 83 vessels with and without a mural smooth muscle. These vessels are surrounded by a loose 84 myxoid stroma and extravasated erythrocytes.  The surrounding trabecular bone is well 85 organized, with prominent lacunal osteocytes and an overlying single cell layer of osteoblasts. 86 Occasional spicules of necrotic bone are also present. The histopathological findings were 87  6 considered to be consistent with a benign vascular hamartoma (Fig 4). 1 Culture of bone from the 88 site revealed no bacterial isolates after 48 hours of aerobic and anaerobic incubation. 89 At 4-weeks post-surgery the cat tolerated handling without signs of pain. There was mild pelvic 90 limb paraparesis, mild proprioceptive ataxia with no postural reaction delays, and no apparent 91 spinal hyperesthesia on palpation of the thoracolumbar area. At 6-month follow up it was 92 reported that the cat had no recurrence of clinical signs.  93  94 Discussion 95 A hamartoma is an excessive and unorganized growth of normal cells and associated tissue that 96 are intrinsic to the organ in which they occur and is considered to be congenital malformation.2  97 Hamartomas demonstrate minimal growth in the mature animal and are therefore not considered 98 to be neoplastic in origin.3 The majority of hamartomas are diagnosed in young patients, often 99 before the onset of skeletal maturity. 4-6 100 Hamartomas may occur as an incidental finding; however, depending on their location, vascular 101 hamartomas can cause clinical signs secondary to spontaneous hemorrhage, mass effect, or 102 adherence to adjacent tissues.2, 7-9 There are reports of hamartomas occurring in many different 103 species including humans, dogs, cattle, horses, goats and cats where they are reported to occur at 104 multiple different sites and involve many tissue types.1, 7-13 105 Hamartomas causing myelopathic signs have been reported in veterinary species due to both 106 vertebral and intramedullary lesions.1, 6, 7 A previous report of a cat with a vascular hamartoma 107 affecting a cervical vertebra described similar clinical features to those described here, including 108 young age (15 months) and signs of progressive ataxia and paresis.1 Computed tomography 109  7 demonstrated an expansile lesion compressing the spinal cord, which was surgically resected, 110 also resulting in a good outcome. Important differential diagnoses for vascular hamartomas 111 occurring within bone include hemangiomas, hemangioblastomas, and arteriovenous 112 malformations, and these can be differentiated on the basis of histopathological features.14-17 113 Previous studies have described MR characteristics associated with intramedullary hamartomas 114 in the cervical and thoracic spinal cord of dogs.18, 19 In contrast to our case of a vertebral 115 hamartoma, these case reports describe the intramedullary hamartomas as heterogeneously 116 hyperintense compared to normal spinal cord on T2W images, isointense on T1W images, with 117 no evidence of contrast in cervical hamartoma and some peripheral, ventral contrast 118 enhancement in the thoracic hamartoma.18, 19 119 To our knowledge, this is the first report describing the MR characteristics of a vascular 120 hamartoma arising from the vertebrae and the first report of a lumbar vertebral hamartoma in a 121 cat. MR clearly depicted the lesion and its effect of the spinal cord, although the signs were not 122 specific for vertebral hamartoma. The combined findings of MR and CT indicated a solitary, 123 non-aggressive, predominantly osseous lesion, which supported surgical treatment in order to 124 decompress the spinal cord and enable further characterization by histopathology. Based on the 125 presenting case and previous literature the prognosis for a cats with vascular hamartomas 126 associated with vertebral column that can be surgically excised is good.1  127  128 List of Author Contributions 129 Category 1 130 (a) Conception and Design 131  8 Frances Taylor-Brown 132 Elsa Beltran 133 (b) Acquisition of Data 134 Frances Taylor-Brown 135 Chris Lamb 136 Henny Martineau 137 Clare Muir 138 Elsa Beltran 139 (c) Analysis and Interpretation of Data 140 Frances Taylor-Brown 141 Chris Lamb 142 Henny Martineau 143 Clare Muir 144 Elsa Beltran 145  146 Category 2 147 (a) Drafting the Article 148 Frances Taylor-Brown 149 (b) Revising Article for Intellectual Content 150  9 Chris Lamb 151 Henny Martineau 152 Clare Muir 153 Elsa Beltran 154  155 Category 3 156 (a) Final Approval of the Completed Article 157 Frances Taylor-Brown 158 Chris Lamb 159 Henny Martineau 160 Clare Muir 161 Elsa Beltran 162   163  10 References 164 1. Parkes JD, Kline KL, Riedesel EA, Haynes JS. A vascular hamartoma arising from the 165 cervical spine of a cat. J Feline Med Surg 2009;11:624-627.  166 2. Summers BA, Cummings JF, de Lahunta A. Veterinary neuropathology. St. Louis (MO): 167 Mosby;1995:pp352-355. 168 3. Morris GF, Murphy K, Rorke LB, James HE. Spinal hamartomas: a distinct clinical entity. J 169 Neurosurg 1998;88:954–957. 170 4. Padgett SL, Tillson DM, Henry CJ, Buss MS. Gingival vascular hamartoma with associated 171 paraneoplastic hyperglycemia in a kitten. J Am Vet Med Assoc 1997;210:914–915. 172 5. Wilson RB. Gingival vascular hamartoma in three calves. J Vet Diagn Invest 1990;2:338–339. 173 Sanders SG, Bagley RS, Gavin PR, Konzik RL, Cantor GH. Surgical treatment of an 174 intramedullary spinal cord hamartoma in a dog. J Am Vet Med Assoc 2002;221:659–661. 175 6. Middleton JR, Valdez R, Britt LG, Parish SM, Tyler JW. Progressive hindlimb paraparesis in 176 a goat associated with a vascular hamartoma. Vet Rec 1999;144:264–265. 177 7. Sanders SG, Bagley RS, Gavin PR, Konzik RL, Cantor GH. Surgical treatment of an 178 intramedullary spinal cord hamartoma in a dog. J Am Vet Med Assoc 2002;221:659–661. 179 8. Stalin CE, Granger N, Jeffery ND. Cerebellar vascular hamartoma in a British Shorthair cat. J 180 Feline Med Surg 2008;10:206–211. 181 9. Smith SH, Van Winkle T. Cerebral vascular hamartomas in five dogs. Vet Pathol 182 2001;38:108-112. 183  11 10. Martin-Vaquero P, Moore SA, Wolk KE, Oglesbee MJ. Cerebral vascular hamartoma in a 184 geriatric cat. J Feline Med Surg 2011;13:286-290. 185 11. Benoit JM, Lefebvre RC, Mulon PY, Raggio I, Dore M. Ovarian vascular hamartoma in a 186 cow. Can Vet J 2005;46:1026-8.  187 12. Corzo-Menendez N, White RN, Whitelock RG, Blunden AS. Vascular hamartoma within the 188 flexor muscles of the left carpus in a dog. J Small Anim Pract 2001;42:399-402.  189 13. Njoku CO, Henry JD, Cook JE, Guffy MM. Pulmonary vascular hamartoma in a dog. J Am 190 Vet Med Assoc 1972;161:378-381.  191 14. Zaki FA. Vascular malformation (cavernous angioma) of the spinal cord in a dog. J Small 192 Anim Pract 1979;20:417–422. 193 15. Cordy DR. Vascular malformations and hemangiomas of the canine spinal cord. Vet Pathol 194 1979;6:275–282. 195 16. Kloc PA II, Scrivani PV, Barr SC, et al. Vertebral angiomatosis in a cat. Vet Radiol 196 Ultrasound 2001;42:42–45. 197 17. Wells MY, Weisbrode SE. Vascular malformations in the thoracic vertebrae of three cats. 198 Vet Pathol 1987;24:360–361. 199 18. Sanders G, Bagley R, Gavin PR, Konzik RL, Cantor GH. Surgical treatment of an 200 intrameduallry spinal cord hamartoma in a dog. J Am Vet Med Assoc 2002;221:659–661. 201 19. Alexander K, Huneault L, Foster R, d'Anjou MA. Magnetic resonance imaging and 202 marsupialization of a hemorrhagic intramedullary vascular anomaly in the cervical portion of the 203 spinal cord of a dog. J Am Vet Med Assoc 2008;232:399–404.  204  12 Legends 205 Figure 1: Midline sagittal T2-weighted (A) and transverse T2-weighted (B) and T1-weighted 206 pre- (C) and post-contrast (D) through the mid-body of L2. There is a focal extradural mass 207 lesion associated with the left pedicle and lamina of the L2 vertebra within the vertebral canal 208 causing marked displacement of the spinal cord. The mass is iso-to hypointense to normal gray 209 matter on T2-weighted images (A, B) and hypointense on T1-weighted images (C). There is 210 moderate, homogenous contrast enhancement of the central zone of the mass and marked 211 contrast enhancement along its interface with the vertebral canal (D).  212  213  214  13 Figure 2: Transverse (A) CT image and sagittal (B) and dorsal (C) multiplanar reformatted 215 images showing a focal, calcified extradural mass lesion associated with the left pedicle and 216 lamina of the L2 vertebra. Adjacent vertebrae are unaffected.  217  218   219  14 Figure 3: Intra-operative photograph of the L2 lesion at the hemilaminectomy site. (A) The 220 appearance of normal inner cortical bone of L1 (*) contrasts with the proliferative tissue within 221 the vertebral canal of L2 (arrow). (B) Removal of the proliferative tissue to expose the dura 222 (arrowhead) surrounding the spinal cord. 223  224 Figure 4: Hematoxylin and eosin section (at x 600 magnification) shows irregular proliferations 225 of plump endothelial cells (arrow), which form numerous small calibre blood vessels. These 226 vessels are surrounded by a loose myxoid stroma (*) and numerous extravasated erythrocytes 227 (arrowhead). Scale bar = 30µm. 228  229 

Imaging diagnosis-imaging and histopathologic characteristics of a vertebral hamartoma in a cat: Vertebral Hamartoma in a Cat

RVC Research Online

Frances E. Taylor-Brown

Christopher R. Lamb

Henny Martineau

Clare Muir

Elsa Beltran

Crossref

Veterinary Radiology & Ultrasound

IMAGING DIAGNOSIS-IMAGING AND HISTOPATHOLOGIC CHARACTERISTICS OF A VERTEBRAL HAMARTOMA IN A CAT

https://researchonline.rvc.ac.uk/id/eprint/10629/1/10629.pdf

Imaging diagnosis-imaging and histopathologic characteristics of a vertebral hamartoma in a cat: Vertebral Hamartoma in a Cat

Abstract

Similar works

Full text

Available Versions

RVC Repository (Royal Veterinary College)

RVC Research Online

Crossref