兽研背景
原发性气管内肿瘤在小动物和人类中均不常见；然而，它们与高发病率和高死亡率相关，尤其是在诊断延迟的情况下（Nilssen等，2023；Huang等，2024）。在Berrocal等（2025）对1961年至2024年犬猫气管肿瘤的综合综述中，他们发现这些肿瘤仅占呼吸道恶性肿瘤的一小部分。在犬和猫中，鳞状细胞癌、骨软骨瘤和腺瘤是该解剖部位最常报告的肿瘤（Behrens等，2022；An等，2024）。具体在犬中，已报告的气管肿瘤包括骨软骨瘤、恶性上皮性肿瘤和浆细胞瘤，其中后者是记录最少的类型之一（Berrocal等，2025）。
浆细胞肿瘤包括多发性骨髓瘤和孤立性浆细胞瘤，后者又细分为骨型和髓外型；这些肿瘤起源于产生免疫球蛋白的分化B淋巴细胞（Hayes等，2007；Mikiewicz等，2016）。髓外浆细胞瘤（EMP）主要发生于犬、猫和马的皮肤，约占犬皮肤肿瘤的1.5%（Boes和Durham，2017）。尽管EMP可累及其他器官，包括口腔、胃肠道、肝脏、脾脏、肺和中枢神经系统，但气管受累极为罕见。在Mulka等（2025）报告10例犬喉气管浆细胞瘤（5例气管、5例喉部）的回顾性系列之前，已发表的气管EMP个案报告不足10例（Elmenhorst等，2018；Ferronato等，2023）。犬气管EMP的真实发病率仍不清楚；因此，流行病学论断必须谨慎解读（Berrocal等，2025）。
临床上，气管内肿瘤患犬可表现出与上呼吸道梗阻一致的症状，包括干性咳嗽、喘鸣、呼吸困难、运动不耐受和发绀发作，与年龄、性别或品种无关（Ferronato等，2023；Galeno等，2025）。诊断和分期包括临床和实验室评估，并结合诊断影像学，如X线摄影、超声检查，尤其是气管镜检查，可直接观察病变、采集样本并制定治疗方案（Joffe等，2020；Valente等，2024）。在一项犬气管肿物诊断技术的前瞻性比较中，De Lorenzi等（2025a，b）证明支气管内针吸活检、支气管刷检和钳夹活检在实现明确诊断方面各自具有互补作用。
治疗通常以手术切除为基础，根据肿瘤的范围和生物学行为决定是否联合化疗。然而，由于解剖入路受限、出血风险、术中通气不稳定以及与犬体型和设备相关的局限性，气管手术在技术上具有难度（Miller等，2020）。尽管已有报道采用气管切除吻合等开放手术方式治疗各种气管肿瘤（Behrens等，2022），但介入内镜技术的进步通过实现更精确、创伤更小的操作，扩大了治疗选择，并可能减少并发症（Hur等，2025；Joffe等，2020；Britany等，2015）。气管肿物的内镜技术包括息肉圈套器、活检钳和电外科设备，每种技术在出血控制和切缘评估方面各有特定的优势和局限性。
本报告描述了一例犬气管内浆细胞瘤的介入内镜管理。尽管该肿瘤的气管位置罕见，但本报告的主要教育价值不在于病变的罕见性，而在于从介入气管镜检查期间处理严重术中出血中获得的实践经验。所采用的技术策略——立即更换内镜、拔除气管导管和放置双极电外科钳——为类似的气道紧急情况提供了一种实用的补救方法。
病例介绍
一只8岁未去势雄性标准贵宾犬，体重12.5 kg，因两个月干性咳嗽和体力活动诱发的间歇性呼吸困难就诊。
就诊时，患犬安静但警觉。呼吸频率为每分钟32次（参考范围10–30），脉搏血氧饱和度测定的氧饱和度（SpO₂）在室内空气中为94%，提示轻度低氧血症。胸部听诊显示吸气和呼气用力增加，伴有上气道传导音。黏膜粉红湿润。其余体格检查无异常。临床表现与部分上呼吸道梗阻一致。
血液学和生化参数均在正常范围内。腹部超声检查未见病理改变或转移性疾病证据。曾考虑胸部计算机断层扫描（CT），但由于经济限制以及X线摄影和气管镜检查可立即用于诊断和治疗干预，未进行CT检查。
该动物作为巴西帕拉联邦大学（UFPA）兽医研究所兽医医院常规临床操作的一部分接受了治疗。所有诊断和治疗干预均按照机构动物护理伦理指南进行。操作前已获得犬主的书面知情同意，授权进行诊断性检查、治疗性气管镜检查以及随后为科学目的发表临床数据和术中图像。
诊断程序
侧位投照的颈部X线摄影发现一个中等不透X线的结节状结构，大小约为1.21 × 1.13 cm，附着于颈部气管背侧壁（图1）。颈部结构或肺实质中未观察到其他影像学异常。基于此发现，选择在全身麻醉下进行诊断性和治疗性气管镜检查作为下一步。根据美国麻醉医师协会的标准，该犬被归类为ASA II级（Mayhew et al. 2019）。
[图：侧位投照的颈部X线片显示一个结节状结构附着于气管背侧壁，位于]
治疗
麻醉前用药为美沙酮（0.2 mg kg⁻¹），于诱导前10分钟静脉注射。使用丙泊酚（6.0 mg kg⁻¹ IV至效应）诱导麻醉，并以丙泊酚（0.4 mg kg⁻¹ min⁻¹）和瑞芬太尼（7 μg kg⁻¹ h⁻¹）持续速率输注维持全静脉麻醉。动物最初使用7.5 mm气管导管插管，并进行了诊断性和治疗性气管镜检查。
并发症：插管过程中，导管意外接触到气管肿物。最初通过气管导管引入3.1 mm柔性视频内窥镜（Kiron Vet®；工作长度100 cm；视野30°），发现肿物已被压缩并部分塌陷于气管背侧壁。当气管导管向头侧移动以清理术野时，肿物发生大量出血，存在血液误吸和气道阻塞的紧迫风险。
抢救策略：立即修改手术方案。将较小口径的内窥镜更换为较大口径（5.9 mm，Kiron Vet®；工作长度40 cm；0°前视角）设备，以提高灌洗和吸引能力。由于较大内窥镜无法通过气管导管，遂拔除导管并经鼻导管补充氧气。间断血液吸引操作困难，实现了暂时性止血，防止了肺部误吸，并部分恢复了病变基底的视野。尝试使用息肉切除圈套器进行初步切除，但无效，因为出血立即复发。
确定性切除：随后平行于内窥镜引入双极电外科镊，直接夹持并凝固肿物基底。这实现了对出血的确定性控制，并允许对病变进行内镜下大体切除（肉眼可见肿瘤的大体移除）。切除后，气管腔未见活动性出血，邻近黏膜保持完好（图2A–C）。
[图：在疑似气管内肿瘤的犬气管镜检查中观察到的气管肿物。（A）溃疡性结节附着]
在拔除气管导管之前，使用控制性机械通气（限压呼吸机，吸气峰压12 cmH₂O，频率10次/分钟）。在拔除气管导管以允许器械平行放置后，犬维持自主通气，经置于右侧鼻孔腹侧鼻道的鼻导管补充氧气（100%氧气，2 L/min）。在此阶段，通过脉搏血氧仪（探头置于舌部）持续监测SpO₂，保持在90%以上；临床评估呼吸频率和呼吸做功；通过连接鼻导管的侧流适配器测量呼气末CO₂。由于出血的紧急性质以及鼻导管技术在氧合方面的充分性，未使用替代气道装置（如喉罩气道、带通气口的硬质支气管镜）。拔管后未继续控制性通气，因为自主呼吸足以维持氧合，同时内镜医师专注于止血。曾考虑替代气道管理策略，包括临时气管造口术、硬质通气支气管镜和喷射通气，但未实施。
结局
犬从麻醉中恢复满意，并于当日出院。出院前，犬在医院监测约6小时，期间每2小时评估呼吸频率和呼吸做功，通过脉搏血氧仪持续测量SpO₂，在室内空气下保持在96%以上。嘱主人在家监测任何呼吸窘迫、咳嗽或声音改变的迹象，并在15天时返回复查。未进行术后内镜检查或影像学检查，因为犬保持临床呼吸正常，无咳嗽或呼吸困难。药物治疗包括美洛昔康（0.1 mg kg⁻¹ SID）、安乃近（25 mg kg⁻¹ BID）和曲马多（4 mg kg⁻¹ BID）。动物于当日出院。
组织病理学和免疫组织化学检查证实为髓外浆细胞瘤，Ki-67增殖指数约为45%（图3）。根据现有诊断检查（三视角胸部X线摄影、腹部超声检查、全血细胞计数、血清生化及尿液分析），未发现转移性疾病或全身性受累的证据。因此，该犬的检查结果符合孤立性结外病变，与I期相符（Holler et al. 2022; Fend et al. 2023）。然而，作者承认，按照综合性浆细胞肿瘤指南进行正式分期分类需要额外检测（血清蛋白电泳、骨髓评估及区域淋巴结细胞学检查）。
[图：犬切除气管肿物的组织病理学显微照片。气管腔内的浆细胞瘤。圆形细胞]
术前未进行凝血功能检测（血小板计数、凝血酶原时间及活化部分凝血活酶时间）。该犬无出血倾向病史，体格检查未发现瘀点、瘀斑或其他凝血功能障碍体征。作者承认此为一项局限性。
功能结局
在15天复评时，该犬一般状况良好，无呼吸窘迫或肿瘤复发迹象。经内镜下大体切除后，气管通畅性恢复，就诊时的临床症状消退。该犬被转诊进行持续肿瘤学随访，迄今为止临床状况保持稳定。在本单一病例中，气管镜引导下双极电外科切除可行，并实现了短期临床缓解。
讨论
气管髓外浆细胞瘤是犬的一种不常见肿瘤，在一项回顾性系列研究中相关病例不足十例（Mulka et al. 2025; Berrocal et al. 2025）。本病例强调了气管插管接触脆性气管内肿物所诱发的出血。插管过程中避免肿瘤接触至关重要；替代方案包括在内镜引导下使用较小口径导管插管，或插管前进行气管镜检查（De Lorenzi et al. 2025a, b）。未进行CT检查，尽管其可提供肿瘤尺寸和区域淋巴结的信息（Berrocal et al. 2025）。出血控制通过使用较大口径内镜进行吸引、拔除导管以及使用双极电外科镊直接凝血来实现。如病例介绍中所述，未进行凝血功能检测；未来病例应包括血小板计数、PT和aPTT。
气管肿物选择介入内镜技术还是开放手术入路取决于肿瘤特征、可用设备和临床医生经验。息肉切除圈套器已用于气管肿物切除，但存在再出血风险（Queen et al. 2010; Howard et al. 2017）。二极管激光手术是一种替代方案，但存在热损伤风险（De Lorenzi and Solano-Gallego 2009）。如本病例所使用的双极电外科镊可同时实现抓取、凝血和横断，与圈套器息肉切除相比可能减少再出血。气管切除吻合术仍是金标准，可提供完整组织学边缘评估和潜在治愈可能（Behrens et al. 2022; Miller et al. 2020）。然而，切除吻合术伴随更高的并发症发生率、更长的住院时间、吻合口裂开或狭窄的风险，且需要专业外科技术。内镜切除手术时间更短、术后疼痛更轻、可当日出院且费用更低，但受限于无法评估组织学边缘和不完全切除的风险。内镜切除的适应证包括小型、无蒂、腔内且无壁层侵犯的肿物。当完整组织学清除至关重要或肿物较大或具有侵袭性时，首选开放手术（Behrens et al. 2022）。
髓外浆细胞瘤的分期包括三视角胸部X线摄影、腹部超声检查、全血细胞计数、血清生化及尿液分析。虽然现有发现符合局限性疾病且无全身性受累证据，但缺乏全身性浆细胞肿瘤的确认性检测，特别是血清蛋白电泳、骨髓评估和区域淋巴结细胞学检查，构成一项局限性（Mulka et al. 2025）。Ki-67指数约为45%，超过犬髓外浆细胞瘤的典型范围（5%-25%）（Mulka et al. 2025）。然而，由于未进行完整肿瘤学分期的和因电灼伪影无法评估组织学边缘，该发现的预后意义仍不确定。12个月无复发间期令人鼓舞，但应将其解释为一项令人鼓舞的观察结果，而非完全局部肿瘤控制已实现的证据。晚期复发不能排除，任何关于内镜切除减轻了Ki-67指数预后影响的说法仍属推测。
本报告的主要贡献不在于证明内镜下肿瘤切除术的长期疗效，而在于详细描述了在处理危及生命的气道并发症时的术中决策和出血管理。该犬良好的临床结局表明，气管内浆细胞瘤的肉眼内镜切除术是可行的。然而，所描述的技术顺序——立即更换内镜、拔除气管导管以及放置双极电外科镊——为类似的气道急症提供了一种实用的救援策略，这正是本病例的主要教学价值所在。
结论
本病例表明，介入性气管镜检查可以作为气管内肿瘤止血和内镜下切除的可行选择。快速更换为大口径内镜以便吸引、拔除气管导管以便平行放置器械，以及使用双极电外科镊进行直接凝血，实现了止血和气管内浆细胞瘤的肉眼内镜切除（肉眼可见病变的大体切除）。单例病例不能证明安全性或有效性，但本文所描述的技术顺序为类似的气道急症提供了一种实用的救援策略。
致谢
作者衷心感谢视频外科、产科与生殖（VOR）团队以及GINVET-动物健康与福利技术创新研究组、巴西国家科学技术发展委员会（CNPq）、巴西高等教育人员促进协调委员会（CAPES）以及帕拉联邦大学科研与研究生事务副校长办公室（Propesp/UFPA）对本研究的资助。
作者贡献
JIOM和PPMT构思并设计了研究，协调了数据收集和分析，并起草了手稿。KBdS和RSdJ参与了内镜操作的实施和数据收集。JIOM、KBdS、RSdJ、AVN和PPMT参与了手术操作。FDOM、RMCT和RT：可视化、形式分析、撰写——初稿、撰写——审阅与编辑。AVN、RMCT、RT和PPMT参与了方法学开发。PSBJ、SFdS、FDOM和PPMT监督了研究，参与了数据解读并对稿件进行了批判性审阅。所有作者审阅并批准了最终版本。
资助
本研究发表的文章处理费（APC）由巴西高等教育人员促进协调委员会（CAPES）资助（ROR标识符：00x0ma614）。本研究在巴西高等教育人员促进协调委员会（CAPES）的支持下开展，通过硕士学位奖学金（资助代码001）提供资助。
数据可用性
本研究期间未生成或分析任何数据集。
声明
伦理批准
本研究经帕拉联邦大学动物伦理委员会（CEUA-UFPA）批准，方案编号2741260522，并按照机构和国家动物福利标准开展。
利益冲突
作者声明无利益冲突。
脚注
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参考文献
[内容请查看原文]
关联数据
数据可用性声明
本研究期间未生成或分析任何数据集。
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Background
Primary intratracheal neoplasms are uncommon in small animals and humans; however, they are associated with high morbidity and mortality, especially when diagnosis is delayed (Nilssen et al. 2023; Huang et al. 2024). In a comprehensive review of tracheal neoplasia in dogs and cats from 1961 to 2024, Berrocal et al. (2025) identified that these tumours account for a small fraction of respiratory tract malignancies. In dogs and cats, squamous cell carcinoma, osteochondroma, and adenoma are the most frequently reported neoplasms at this anatomic site (Behrens et al. 2022; An et al. 2024). In dogs specifically, reported tracheal tumours include osteochondroma, malignant epithelial neoplasms, and plasma cell tumours, with the latter group being among the least frequently documented (Berrocal et al. 2025).
Plasma cell tumours include multiple myeloma and solitary plasmacytoma, and the latter is subdivided into osseous and extramedullary forms; these tumours originate from differentiated B lymphocytes that produce immunoglobulins (Hayes et al. 2007; Mikiewicz et al. 2016). Extramedullary plasmacytoma (EMP) occurs predominantly on the skin of dogs, cats, and horses and accounts for approximately 1.5% of canine cutaneous tumours (Boes and Durham 2017). Although EMP may affect other organs, including the oral cavity, gastrointestinal tract, liver, spleen, lungs, and central nervous system, tracheal involvement is extremely rare. Prior to the retrospective series by Mulka et al. (2025), which reported ten cases of canine laryngotracheal plasma cell tumours (five tracheal and five laryngeal), fewer than ten individual case reports of tracheal EMP had been published (Elmenhorst et al. 2018; Ferronato et al. 2023). The true incidence of tracheal EMP in dogs remains unknown; therefore, epidemiological claims must be interpreted cautiously (Berrocal et al. 2025).
Clinically, dogs with intratracheal neoplasms can have signs consistent with upper respiratory tract obstruction, including nonproductive cough, stridor, dyspnea, exercise intolerance, and episodes of cyanosis, regardless of age, sex, or breed (Ferronato et al. 2023; Galeno et al. 2025). Diagnosis and staging involve clinical and laboratory evaluation combined with diagnostic imaging, such as radiography, ultrasonography, and especially tracheoscopy, allowing direct visualisation of the lesion, sample collection, and therapeutic planning (Joffe et al. 2020; Valente et al. 2024). In a prospective comparison of diagnostic techniques for canine tracheal masses, De Lorenzi et al. (2025a, b) demonstrated that endobronchial needle aspiration, bronchial brushing, and forceps biopsy each have complementary roles in achieving a definitive diagnosis.
Treatment is generally based on surgical resection, with or without chemotherapy, depending on the extent and biological behaviour of the neoplasm. However, tracheal surgery is technically difficult due to restricted anatomic access, the risk of haemorrhage, intraoperative ventilatory instability, and limitations related to dog size and available equipment (Miller et al. 2020). Although open surgical approaches such as tracheal resection and anastomosis have been reported for various tracheal tumours (Behrens et al. 2022), advances in interventional endoscopy have increased therapeutic options by allowing more precise and less invasive procedures, with a potential reduction in complications (Hur et al. 2025; Joffe et al. 2020; Britany et al. 2015). Endoscopic techniques for tracheal masses include polypectomy snares, biopsy forceps, and electrosurgical devices, each with specific advantages and limitations regarding haemorrhage control and margin assessment.
This report describes the interventional endoscopic management of an intratracheal plasmacytoma in a dog. Although the tracheal location of this neoplasm is rare, the primary educational value of this report lies not in the lesion's rarity, but in the practical lessons learned from managing a severe intraoperative haemorrhage during interventional tracheoscopy. The technical strategies employed, immediate endoscope exchange, removal of the endotracheal tube, and bipolar electrosurgical forceps placement, offer a practical rescue approach for similar airway emergencies.
Case presentation
An 8-year-old intact male Standard Poodle, weighing 12.5 kg, was presented with a two-month history of nonproductive cough and intermittent episodes of dyspnea triggered by physical activity.
On presentation, the dog was quiet but alert. The respiratory rate was 32 breaths per minute (reference range 10–30), and oxygen saturation (SpO₂) measured by pulse oximetry was 94% on room air, indicating mild hypoxemia. Thoracic auscultation revealed increased inspiratory and expiratory effort with referred upper airway noise. Mucous membranes were pink and moist. The remainder of the physical examination was unremarkable. The clinical presentation was consistent with partial upper respiratory tract obstruction.
Hematologic and biochemical parameters were within normal limits. Abdominal ultrasonography revealed no pathological alterations or evidence of metastatic disease. Thoracic computed tomography (CT) was considered but was not performed due to financial constraints and the immediate availability of radiography and tracheoscopy for diagnostic and therapeutic intervention.
The animal was treated as part of a routine clinical procedure at the Veterinary Hospital of the Institute of Veterinary Medicine of the Universidade Federal do Pará (UFPA), Brazil. All diagnostic and therapeutic interventions were performed in accordance with institutional ethical guidelines for animal care. Written informed consent was obtained from the dog's owner prior to the procedure, authorising the diagnostic investigation, the therapeutic tracheoscopy, and the subsequent publication of clinical data and intraoperative images for scientific purposes.
Diagnostic procedures
Cervical radiography in the lateral projection identified a moderately radiopaque nodular structure measuring approximately 1.21 × 1.13 cm, attached to the dorsal wall of the cervical trachea (Fig. 1). No other radiographic abnormalities were observed in the cervical structures or the pulmonary parenchyma. Based on this finding, diagnostic and therapeutic tracheoscopy under general anaesthesia was elected as the next step. The dog was classified as ASA II according to the criteria of the American Society of Anesthesiologists (Mayhew et al. 2019).
[图：Cervical radiograph in the lateral projection showing a nodular structure attached to the dorsal wall of the trachea in ]
Treatment
Premedication consisted of methadone (0.2 mg kg⁻1) administered intravenously 10 min before induction. Anaesthesia was induced with propofol (6.0 mg kg⁻1 IV to effect) and maintained with total intravenous anaesthesia using propofol (0.4 mg kg⁻1 min⁻1) and remifentanil (7 μg kg⁻1 h⁻1) as continuous rate infusions. The animal was initially intubated with a 7.5‑mm endotracheal tube, and diagnostic and therapeutic tracheoscopy was performed.
Complication: During intubation, the tube inadvertently contacted the tracheal mass. A 3.1-mm flexible video endoscope (Kiron Vet®; 100 cm working length; 30° field of view) was initially introduced through the endotracheal tube, revealing that the mass had been compressed and partially collapsed against the dorsal tracheal wall. When the endotracheal tube was moved cranially to clear the surgical field, substantial haemorrhage from the mass occurred, posing an imminent risk of blood aspiration and airway obstruction.
Rescue strategy: The surgical plan was immediately modified. The smaller-calibre endoscope was replaced with a larger (5.9 mm, Kiron Vet®; 40 cm working length; 0° forward view) device to improve lavage and suction capacity. Because the larger endoscope could not pass through the endotracheal tube, the tube was removed and oxygen was supplemented via a nasal catheter. Intermittent blood aspiration was performed with difficulty, achieving temporary hemostasis, preventing pulmonary aspiration, and partially restoring visualization of the base of the lesion. Initial resection with a polypectomy snare was attempted but was ineffective, as bleeding recurred immediately.
Definitive excision: Bipolar electrosurgical forceps were then introduced parallel to the endoscope, directly grasping and coagulating the base of the mass. This provided definitive control of haemorrhage and allowed gross endoscopic excision (macroscopic removal of the visible tumour) of the lesion. After removal, the tracheal lumen showed no active bleeding and preserved adjacent mucosa (Fig. 2A–C).
[图：Tracheal mass observed during tracheoscopy in a dog with suspected intratracheal neoplasia. ( A ) Ulcerated nodule attac]
Before removal of the endotracheal tube, controlled mechanical ventilation was used (pressure-limited ventilator, peak inspiratory pressure 12 cmH₂O, rate 10 breaths per minute). After the endotracheal tube was removed to permit parallel placement of instruments, the dog was maintained on spontaneous ventilation with oxygen supplementation (100% oxygen at 2 L/min) delivered via a nasal catheter placed in the ventral meatus of the right nostril. During this phase, SpO₂ was monitored continuously via pulse oximetry (probe placed on the tongue) and remained above 90%; respiratory rate and effort were assessed clinically; end-tidal CO₂ was measured via a side-stream adapter connected to the nasal catheter. No alternative airway device (e.g., laryngeal mask airway, rigid bronchoscope with ventilation port) was used due to the emergency nature of the haemorrhage and the adequacy of the nasal catheter technique for oxygenation. Controlled ventilation was not continued after tube removal, as spontaneous breathing was sufficient to maintain oxygenation while the endoscopist focused on haemostasis. Alternative airway management strategies, including temporary tracheostomy, rigid ventilating bronchoscopy, and jet ventilation, were considered but not implemented.
Outcomes
The dog recovered satisfactorily from anesthesia and was discharged the same day. Before discharge, the dog was monitored for approximately 6 h in the hospital, during which respiratory rate and effort were assessed every 2 h, with SpO₂ measured continuously via pulse oximetry, remaining above 96% on room air. The owner was instructed to monitor at home for any signs of respiratory distress, cough, or voice change, and to return for reevaluation at 15 days. No postoperative endoscopy or imaging was performed because the dog remained clinically eupneic without cough or dyspnea. Medical management included meloxicam (0.1 mg kg⁻1 SID), dipyrone (25 mg kg⁻1 BID), and tramadol (4 mg kg⁻1 BID). The animal was discharged on the same day.
Histopathological and immunohistochemical examination confirmed extramedullary plasmacytoma with a Ki‑67 proliferation index of approximately 45% (Fig. 3). Based on the available diagnostic investigations (three-view thoracic radiography, abdominal ultrasonography, complete blood count, serum biochemistry, and urinalysis), no evidence of metastatic disease or systemic involvement was identified. The dog therefore had findings compatible with a solitary extranodal lesion, which would be consistent with stage I (Holler et al. 2022; Fend et al. 2023). However, the authors acknowledge that formal stage classification per comprehensive plasma cell tumour guidelines would require additional testing (serum protein electrophoresis, bone marrow evaluation, and regional lymph node cytology).
[图：Histopathological photomicrographs of the excised tracheal mass of a dog. Plasmacytoma in the tracheal lumen. Round cell]
Preoperative coagulation testing (platelet count, prothrombin time, and activated partial thromboplastin time) was not performed. The dog had no history of bleeding tendency, and physical examination revealed no petechiae, ecchymoses, or other signs of coagulopathy. The authors acknowledge this as a limitation.
Functional outcome
At the 15‑day reevaluation, the dog was in good general condition with no signs of respiratory distress or tumour recurrence. Following gross endoscopic excision, tracheal patency was restored and the presenting clinical signs resolved. The dog was referred for ongoing oncologic follow-up and, to date, remains clinically stable. In this single case, tracheoscopy-guided bipolar electrosurgical excision was feasible and resulted in short-term clinical resolution.
Discussion
Tracheal extramedullary plasmacytoma is an uncommon neoplasm in dogs, with fewer than ten related cases in a retrospective series (Mulka et al. 2025; Berrocal et al. 2025). This case emphasises haemorrhage precipitated by endotracheal tube contact with a friable intratracheal mass. Prevention of tumour contact during intubation is critical; alternatives include smaller calibre tube intubation under endoscopic guidance or tracheoscopy before intubation (De Lorenzi et al. 2025a, b). CT was not performed, although it could have provided information on tumour dimensions and regional lymph nodes (Berrocal et al. 2025). Haemorrhage control was achieved using a larger-calibre endoscope for suction, removal of the tube, and bipolar electrosurgical forceps for direct coagulation. As noted in the Case Presentation, coagulation testing was not performed; future cases should include platelet count, PT, and aPTT.
The choice between interventional endoscopic techniques and open surgical approaches for tracheal masses depends on tumour characteristics, available equipment, and clinician expertise. Polypectomy snares have been used for removal of tracheal masses but carry a risk of recurrent bleeding (Queen et al. 2010; Howard et al. 2017). Diode laser surgery is an alternative but carries risks of thermal injury (De Lorenzi and Solano-Gallego 2009). Bipolar electrosurgical forceps, as used in this case, offer simultaneous grasping, coagulation, and transection, which may reduce rebleeding compared to snare polypectomy. Tracheal resection and anastomosis remain the gold standard and offer the possibility of complete histological margin assessment and potential cure (Behrens et al. 2022; Miller et al. 2020). However, resection and anastomosis are associated with greater morbidity, longer hospitalisation, risks of anastomotic dehiscence or stricture, and requires specialised surgical expertise. Endoscopic excision offers shorter procedure time, reduced postoperative pain, same-day discharge, and lower cost, but is limited by the inability to assess histological margins and the risk of incomplete resection. Indications for endoscopic excision include small, sessile, intraluminal masses without mural invasion. Open surgery is preferred when complete histological clearance is essential or when the mass is large or invasive (Behrens et al. 2022).
Staging for extramedullary plasmacytoma included three-view thoracic radiography, abdominal ultrasonography, complete blood count, serum biochemistry, and urinalysis. While the available findings are compatible with localised disease without evidence of systemic involvement, the absence of confirmatory testing for systemic plasma cell neoplasia, specifically serum protein electrophoresis, bone marrow evaluation, and regional lymph node cytology, represents a limitation (Mulka et al. 2025). The Ki-67 index of approximately 45% exceeds the typical range for canine extramedullary plasmacytoma (5–25%) (Mulka et al. 2025). However, because complete oncologic staging was not performed and histological margins were not assessable due to cautery artefact, the prognostic implications of this finding remain uncertain. The 12-month recurrence-free interval is encouraging but should be interpreted as an encouraging observation rather than evidence that complete local tumour control was achieved. Late recurrence cannot be excluded, and any suggestion that endoscopic excision mitigated the prognostic impact of the Ki-67 index remains speculative.
The principal contribution of this report lies not in demonstrating the long-term efficacy of endoscopic tumour excision, but in the detailed description of intraoperative decision-making and haemorrhage management during a life-threatening airway complication. The favourable clinical outcome in this dog demonstrates that gross endoscopic excision of an intratracheal plasmacytoma was feasible. However, the technical sequence described, immediate endoscope exchange, removal of the endotracheal tube, and bipolar electrosurgical forceps placement, offers a practical rescue strategy for similar airway emergencies, which represents the primary educational value of this case.
Conclusions
This case illustrates that interventional tracheoscopy can be a viable option for hemostasis and endoscopic excision of intratracheal neoplasms. Rapid exchange to a larger-caliber endoscope for suction, removal of the tube to permit parallel instrument placement, and bipolar electrosurgical forceps for direct coagulation achieved hemostasis and gross endoscopic excision (macroscopic removal of the visible lesion) of the intratracheal plasmacytoma. A single case does not prove safety or efficacy, yet the technical sequence described here offers a practical rescue strategy for similar airway emergencies.
Acknowledgements
The authors express their immense gratitude to the team at the Video Surgery, Obstetrics and Reproduction (VOR) group and to the GINVET-Technological Innovations for Animal Health and Welfare research group, the National Council for Scientific and Technological Development (CNPq, Brazil), the Coordination for the Improvement of Higher Education Personnel (CAPES, Brazil) and the Research and Post-graduate Pro-Rector of Pará Federal University (Propesp/UFPA) for financial support in the study.
Author contributions
JIOM and PPMT conceived and designed the study, coordinated data collection and analysis, and drafted the manuscript. KBdS and RSdJ participated in performing endoscopies and collecting data. JIOM, KBdS, RSdJ, AVN and PPMT participated in the surgical procedures. FDOM, RMCT and RT: Visualization, formal analysis, writing – original draft, and writing – review and editing. AVN, RMCT, RT and PPMT contributed to the methodological development. PSBJ, SFdS, FDOM and PPMT supervised the study and contributed to the interpretation of the data and critically reviewed the manuscript. All authors reviewed and approved the final version.
Funding
The Article Processing Charge (APC) for the publication of this research was funded by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) (ROR identifier: 00x0ma614). This study was conducted with support from the Coordination for the Improvement of Higher Education Personnel (CAPES) – Brazil, through a master's degree scholarship (Funding code 001).
Data availability
No datasets were generated or analysed during the current study.
Declarations
Ethical approval
This study was approved by the Animal Ethics Committee of the Federal University of Pará (CEUA-UFPA), protocol no. 2741260522, and conducted in accordance with institutional and national animal welfare standards.
Competing interests
The authors declare no competing interests.
Footnotes
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References
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Associated Data
Data Availability Statement
No datasets were generated or analysed during the current study.