Maxillary unicystic ameloblastoma in a 6‐week‐old filly evaluated with computed tomography

Abstract

Surgical excision was not deemed feasible with an athletic future in mind and the owners elected to euthanase the filly. Histopathologically, the mass was consistent with unicystic ameloblastoma and was lined intermittently with palisading, columnar basal cells (ameloblast-like cells) overlying a zone containing stellate cells in loose stroma. To the authors' knowledge this is the first report of a CT scan of an equine ameloblastoma. Although histopathology was essential for definitive diagnosis, CT clearly defined the origin of the mass and identified its locally extensive, cystic nature, which enabled informed decisions to be made.

Equine odontogenic tumors: Clinical presentation, CT findings, and outcome in 11 horses

“…Both the mare in this series, and in the previous report, 9 did not have a complete postmortem, therefore, metastases could not be excluded. Radiation therapy arrested growth of the mass for 6 months but was unsuccessful in diminishing the maxillary tumor growth in this case (5), even with prior surgical debulking. Surgical resection was performed in a previous case report of canine mandibular ameloblastic carcinomas, with no recurrence of the tumor.…”

“…4 They are predominantly found within the mandible of older horses, although they have also been reported in three foals. 4,5 These tumors can be discrete but can also be locally aggressive with extensive bone loss in advanced stages.…”

“…were treated with radiation therapy. The horse with the 109-110 ameloblastic carcinoma(5) underwent several subsequent CT examinations of the head. As the mass progressively grew in size, a second cheek tooth was removed,and a large orosinus fistula developed, possibly due to bone necrosis caused by the radiation therapy.…”

Erratum

“…6 The filly had a growing mass over the right maxilla that was causing respiratory distress at exercise. Radiographs showed that the mass originated from the maxilla and was causing deviation of the nasal septum.…”

In this issue – August 2017

“…A case report shows the extraordinary computed tomography (CT) appearance of a maxillary ameloblastoma in a Thoroughbred foal . The filly had a growing mass over the right maxilla that was causing respiratory distress at exercise.…”