23/12/2024
【什麼是唾液腺囊腫❓】
#唾液腺囊腫（sialocele or salivary mucocle）是指 #唾液腺 或 #唾腺管 破裂（可能為創傷、病理性或不明原因所造成），導致唾液滲漏入周圍組織，並累積在組織間形成囊腫樣的一種病理狀態。這些唾液在原本不該存在的組織間被視為「異物」，一系列發炎反應相繼發生， #肉芽組織 會包圍唾液而形成囊袋樣腫包。
唾液腺囊腫在犬貓都可能發生，在某些品種如 #貴賓犬 及 #德國牧羊犬 較為常見。
狗狗的主要唾液腺一共有四對，分別為 #下頜腺、 #舌下腺、 #耳下腺 及 #顴骨下腺；貓的主要唾液腺除了上述四對之外，另有 #大臼齒腺。此外在口腔及鼻咽也分佈許多小的唾腺組織。
【唾液腺囊腫長什麼樣子❓】
一般而言，唾液腺囊腫為 #無痛、 #柔軟（水袋的觸感）的腫包。這些腫包中充滿唾液，可能導致 #局部腫脹和壓迫。
唾液腺囊腫根據發生的部位可能出現在頭頸部各處，包括舌下、頸部、顴骨下、耳下等，較少見的位置則包括咽部（口腔深處）、鼻咽內，甚至沿著頸部爬進胸腔等。
若長在口腔或鼻咽內，往往在囊腫發展到一定程度、造成如呼吸道的壓迫、吞嚥困難時，才會被飼主發現帶去就醫。當囊腫繼發感染時，則可能引起疼痛和發熱。
【如何診斷唾液腺囊腫❓】
🔍臨床檢查
觸診腫塊來初步確定腫脹的軟硬、位置和大小。
🔍細針抽吸採樣、細胞學檢查
細胞學檢查結果通常有高的診斷價值。
在門診中可透過細針抽吸腫脹部位內液體，取出黏液的顏色通常屬清澈淡黃色或是帶有血絲的粉色。穿刺抽取物的細胞數量相對較少，多含有均一的大型泡沫狀巨噬細胞，在背景中常可看到紫色染色的濃縮黏液聚集體。
🔍影像學檢查
可透過超音波、電腦斷層掃描等進階影像診斷來輔助判斷唾液腺囊腫的位置以及侵犯的範圍，並且擬定手術計畫。值得一提的是，有時造成唾液滲漏的原發唾液腺不一定能準備被診斷出，需要時可能施行唾腺造影，然而其診斷 #敏感性只有約67%，且在小體型的犬貓或是唾腺管阻塞時可能無法成功造影。
【唾液腺囊腫治療方法❓】
🏥保守治療
在一些輕微的病例中，可能可以選擇觀察和定期檢查，如果囊腫不大且沒有引起明顯症狀，可考慮不立即進行手術治療。然而，反覆的細針抽吸唾液雖然可以暫時縮小囊腫，但復發的機率很高，且可能造成後續感染發生。
🏥手術治療
對於較大或影響到動物生活的唾液腺囊腫， #手術是最有效的治療方式。
手術方式多為摘除有影響的唾液腺並盡可能移除囊腫，由於 #狗狗有許多對唾液腺，因此摘除其中一副唾液腺並不會造成太大的影響。口腔內及鼻咽內囊腫則可以造袋術或囊腫壁雷射消融等方式處理。
術後併發症包含手術部位 #血清腫（無需特別處理）及可能造成出血或神經損傷，尤其是摘除如耳下腺及顴骨下腺等在解剖位置上周圍有較多神經血管經過的腺體，需要格外小心。
【唾液腺囊腫治得好嗎❓】
唾液腺囊腫經過正確診斷及適當的手術治療後，通常 #預後良好。大多數動物在術後恢復正常生活，且 #復發率低。然而，若唾液腺囊腫發生的時間較長，侵犯的範圍大，滲入頭頸部各組織間隙時，手術可能變得棘手且相關 #併發症的風險也會升高。
#唾液腺囊腫 #頭頸外科
Sialocele or salivary mucocele refers to a pathological state where the salivary gland or duct ruptures (potentially due to trauma, pathology, or unknown causes). This leads to saliva leakage into surrounding tissues, accumulating and forming a cyst-like structure. The saliva in the tissues, where it normally should not be present, is perceived as a "foreign substance," triggering a series of inflammatory responses. Granulation tissue surrounds the saliva, forming a
sac-like cyst.
Sialocele can occur in both dogs and cats and is more common in certain breeds such as Poodles and German Shepherds. Dogs have four major pairs of salivary glands: mandibular gland, sublingual gland, parotid gland, and zygomatic gland. Cats have the same major pairs, with an additional molar gland. Additionally, many small salivary gland tissues are distributed in the oral cavity and nasopharynx.
【Clinical Presentation】
Depending on the location, sialocele can appear in various areas of the head and neck, including under the tongue, neck area, orbit, and under the ear. Less common locations include the pharynx (deep in the oral cavity), within the nasopharynx, and even extending from the neck into the chest. Generally, sialoceles are painless, soft (resembling the feel of a water balloon) swellings. These cyst-like structures are filled with saliva and may cause localized swelling and pressure. If located within the mouth or nasopharynx, they might be detected only when they develop to a size that causes airway compression or swallowing difficulties, prompting the owner to take the pet to the vet. In cases where the sialocele becomes secondarily infected, it may cause pain and fever.
【Diagnostic Methods】
🔍Clinical Examination:
Palpation of the mass to preliminarily determine the swelling's consistency, location, and size.
🔍Fine-Needle Aspiration and Cytological Examination:
By aspirating fluid from the swollen area, the mucus retrieved is typically transparent or clear light yellow or pink with blood streaks. Cytological examination often has high diagnostic value, revealing relatively few cells, mostly large foamy macrophages, with purple-stained concentrated mucus aggregates visible in the background.
🔍 Imaging Examinations:
Advanced imaging techniques like ultrasound and CT scans can help determine the location and extent of the cyst, aiding in surgical planning. Notably, the primary salivary gland causing the leakage may not always be easily identified, and sialography may be required, although its diagnostic sensitivity is around 67%. In small dogs and cats or blocked ducts, sialography may not be successful.
【Treatment Options】
🏥Conservative Treatment:
In some mild cases, observation and regular check-ups may be an option if the sialocele is small and not causing noticeable symptoms. However, repeated fine-needle aspirations can temporarily reduce the size of the sialocele but have a high recurrence rate and may lead to subsequent infections.
🏥Surgical Treatment:
For larger sialoceles or those affecting the animal's quality of life, surgery is the most effective treatment. It often involves removing the affected salivary gland and as much of the cyst as possible. Since dogs have multiple pairs of salivary glands, removing one or a pair usually does not cause significant issues. Sialocele within the oral cavity and nasopharynx may be treated through marsupialization or laser ablation. Postoperative complications may include seromas at the surgical site, which generally require no specific treatment, and potential bleeding or nerve damage. Special care is needed for glands in anatomically complex areas like the parotid and zygomatic glands, where many nerves and blood vessels are present.
【Prognosis】
The prognosis for sialocele is generally good with proper diagnosis and appropriate surgical treatment. Most animals recover to their normal lives post-surgery with a low recurrence rate. However, if the cyst has been present for a long time, causing extensive tissue involvement, the surgery might be more challenging, increasing the risk of complications.
References:
1. De Lorenzi, D., Bertoncello, D., Mantovani, C., & Bottero, E. (2018). Nasopharyngeal sialoceles in 11 brachycephalic dogs. Veterinary Surgery, 47(3), 431-438.
2. Fossum, T. W. (2018). Small Animal Surgery-Inkling Enhanced E-Book: Small Animal Surgery E-Book. Elsevier Health Sciences.
3. Kneissl, S., Weidner, S., & Probst, A. (2011). CT sialography in the dog–a cadaver study. Anatomia, histologia, embryologia, 40(6), 397-401.
4. Landy, S., Peralta, S., & Fiani, N. (2021). An Atypical Presentation of a Zygomatic Sialocele in a dog. Journal of Veterinary Dentistry, 38(4), 223-230.
5. Nahlieli, O. (2017). Complications of traditional and modern therapeutic salivary approaches. Acta Otorhinolaryngologica Italica, 37(2), 142.
6. Oetelaar, G. S., Heng, H. G., Lim, C. K., & Randall, E. (2022). Computed tomographic appearance of sialoceles in 12 dogs. Veterinary Radiology & Ultrasound, 63(1), 30-37.
7. Reiter, A. M. (2014, May 27). Salivary Disorders in Small Animals. MSD Veterinary Manual. https://www.msdvetmanual.com/digestive-system/diseases-of-the-mouth-in-small-animals/salivary-disorders-in-small-animals
8. Tobias, K. M., & Johnston, S. A. (2013). Veterinary surgery: small animal-E-BOOK: 2-volume set. Elsevier Health Sciences.
9. Torad, F. A., & Hassan, E. A. (2013). Clinical and ultrasonographic characteristics of salivary mucoceles in 13 dogs. Veterinary Radiology & Ultrasound, 54(3), 293-298.
10. Tan, Y. L., Marques, A., Schwarz, T., Mitchell, J., & Liuti, T. (2022). Clinical and CT sialography findings in 22 dogs with surgically confirmed sialoceles. Veterinary Radiology & Ultrasound, 63(6), 699-710.
11. Watanabe, K., Miyawaki, S., Kanayama, M., Takagi, M., Murakami, M., Sugikata, Y., & Yamazoe, K. (2012). First case of salivary mucocele originating from the minor salivary gland of the soft palate in a dog. Journal of Veterinary Medical Science, 74(1), 71-74.
