Smith H L, Rosenblatt A J, Suen W W, Owen H, Ahern B J
School of Veterinary Science, The University of Queensland, Gatton, Queensland 4343, Australia.
Aust Vet J. 2017 Aug;95(8):299-303. doi: 10.1111/avj.12610.
A 6-week-old Thoroughbred filly was presented for evaluation of an expansile mass overlying the right nasal passage and causing respiratory stertor. On skull radiographs, there was a loculated, soft tissue-opaque mass identified dorsal to the right upper premolars and effacing the right nasal cavity. Computed tomography (CT) revealed a locally extensive mass with relatively benign characteristics located centrally on the tooth root apices of the deciduous second premolar (506). The mass extended axially into the right nasal cavity, occluding the meatuses and causing displacement of the nasal septum to the left.
CLINICAL OUTCOME & SIGNIFICANCE: 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.
一匹6周龄的纯种雌马驹因右侧鼻道上方出现膨胀性肿块并导致呼吸呼噜声而前来接受评估。在颅骨X光片上，在右上颌前磨牙背侧发现一个有分隔的软组织不透明肿块，该肿块使右侧鼻腔消失。计算机断层扫描（CT）显示，在乳侧切牙（506）牙根尖中央有一个局部广泛的肿块，具有相对良性的特征。该肿块轴向延伸至右侧鼻腔，阻塞鼻道并导致鼻中隔向左移位。
考虑到其运动前景，手术切除被认为不可行，主人选择对这匹雌马驹实施安乐死。组织病理学检查显示，该肿块符合单囊性成釉细胞瘤，其内壁间断衬有栅栏状柱状基底细胞（成釉细胞样细胞），其下方是含有星状细胞的疏松基质区域。据作者所知，这是马成釉细胞瘤CT扫描的首例报告。虽然组织病理学对明确诊断至关重要，但CT清楚地界定了肿块的起源并确定了其局部广泛的囊性性质，从而能够做出明智的决策。
