Magnetic resonance imaging of a solid, multilobular ameloblastoma in the mandible of a pony

Abstract

SummaryThis report describes a multilobular ameloblastoma that invaded the left mandible of a 31-year-old pony. The pony presented initially with a palpable mass that protruded from the left mandibular region. Ante mortem radiographs of the mass revealed an invasive, multilobular, bony mass with significant loss of dentition. One month following initial diagnostic work-up, the pony was subjected to euthanasia due to unrelated clinical signs of colic, secondary to a strangulating lipoma. Magnetic resonance imaging (MRI) of the head was performed post mortem to further characterise the mass and determine the extent of its invasion. The macroscopic and histopathological morphology and immunohistochemical properties of the neoplastic cells strongly supported a diagnosis of a multi-cystic ameloblastoma. To the authors' knowledge, this is the first report of an MRI of an ameloblastoma in the horse.

Perivascular wall tumour presenting as pastern mass in a Standardbred gelding

“…The superior soft tissue resolution and anatomic detail provided by MRI is becoming increasingly utilized in the characterisation of equine neoplasms 17,22,23 . The use of computed tomography angiography to facilitate successful surgical removal of a fetlock mass (haemangioma) and a tarsal mass (hamartoma) has been reported 10,11 .…”

“…18,20 The superior soft tissue resolution and anatomic detail provided by MRI is becoming increasingly utilized in the characterisation of equine neoplasms. 17,22,23 The use of computed tomography angiography to facilitate successful surgical removal of a fetlock mass (haemangioma) and a tarsal mass (hamartoma) has been reported. 10,11 Whilst location may make complete surgical resection difficult due to the proximity of surrounding structures which are essential for normal limb function, the use of highresolution 3-dimensional imaging modalities such as MRI and computed tomography would allow for detailed pre-surgical planning and prognostication.…”

Use of cone‐beam computed tomography for advanced imaging of the equine patient

“…An increasing number of studies have been published using MRI for evaluation of the equine skull 56 including studies reporting the normal anatomy, 57,58 cranial nerves and various neurologic diseases, 59,60 sinonasal disorders, 61 and pulp cavity of normal and diseased cheek teeth 62 . Clinical use of MRI of the equine skull is primarily limited to single case reports 63‐67 or small case series, 68,69 although one large, multicentre study 70 has been published describing MRI use for a variety of different disorders of the skull. Historically, the MRI units conducive for imaging of the equine skull were open with short or ultra‐short bore configurations, however multiple high‐field closed bore MR units are currently available across the USA and UK for equine imaging.…”

Equine skull magnetic resonance imaging: The where, when and why?

“…The case presentation of the magnetic resonance imaging (MRI) appearance of an equine ameloblastoma in this issue is an excellent example of our continued expansion of knowledge in this area (Koch et al . ). When compared to the use of MRI to detect appendicular skeletal lesions in horses, equine skull MRI represents an area of limited growth.…”

“…This is illustrated in the ameloblastoma case presentation in this issue (Koch et al . ). The rostral and caudal anatomic structures are warped, representing the edge of the uniform magnetic field needed to produce MR images.…”