Zygomatic salivary mucocoele in a Lhasa apso following maxillary tooth extraction

An Atypical Presentation of a Zygomatic Sialocele in a dog

A sialocele is an accumulation of salivary fluid due to leakage into the interstitial space surrounding the affected salivary gland and/or its corresponding duct. Reported causes of salivary leakage include trauma, foreign bodies, sialoliths, and neoplasia, but in many cases the etiology is not identified. Clinical signs of sialoceles associated with the zygomatic salivary gland or corresponding duct usually include exophthalmos due to periorbital salivary accumulation, whereas sialoceles associated with the mandibular or sublingual glands or ducts usually manifest as cervical, pharyngeal and/or sublingual salivary accumulation. This case report describes an atypical cervical presentation of a zygomatic sialocele in a dog that resolved after zygomatic sialoadenectomy.

Computed tomographic appearance of sialoceles in 12 dogs

Published findings on the computed tomographic (CT) appearance of sialoceles are limited to brief descriptions from reported cases in eight dogs and one cat. The authors have seen sialoceles with CT characteristics that are not consistent with these previous reports. The purpose of this multicenter, retrospective, descriptive, case series study was to provide more detailed descriptions of the CT appearance of confirmed sialoceles in dogs. Dogs over a 10-year period with cytologically or histologically confirmed sialoceles and pre- and postcontrast CT studies of the head were included. Multiple qualitative and quantitative features were described for each sialocele with histological correlation. Twelve dogs with a total of 13 sialoceles were identified, including: seven cervical sialoceles, three complex (combined cervical and sublingual) sialoceles, two sublingual sialoceles, and one zygomatic sialocele. All sialoceles were characterized by fluid attenuating, non-contrast enhancing contents (median 18.5 HU) and soft tissue attenuating, contrast-enhancing walls. The external margins of all sialocele walls were smooth; however, the internal margins in six sialoceles were irregular with poorly defined nodular to frond-like protrusions. Mineralized foci of variable size (range < 1 mm to 4.8 mm) and attenuation (range 119 to 1253 HU) were present in seven sialoceles and histologically identified as sialoliths (three sialoceles) and osseous metaplasia (two sialoceles). A unique finding in the sialoceles in this study was the presence of intraluminal nodular to frond-like protrusions arising from the wall. This study also reports the CT appearance of cervical and complex sialoceles and sialocele mineralizations.

Intracanalicular injection of N-acetylcysteine as adjunctive treatment for sialoceles in dogs: 25 cases (2000-2017)

OBJECTIVE

To describe intracanalicular injection of 10% N-acetylcysteine (IINAC) as adjunctive treatment for sialoceles in dogs.

ANIMALS

25 client-owned dogs.

PROCEDURES

Hard copy medical records at 2 veterinary ophthalmology practices were searched to identify dogs that underwent IINAC for treatment of sialoceles from January 2000 to December 2017. Signalment, affected salivary gland, clinical signs, duration of signs, other treatments administered, diagnostic tests performed, anesthetic approach, N-acetylcysteine volume administered, complications, follow-up time, and recurrence of sialoceles were recorded. Descriptive statistics were reported.

RESULTS

Boxers and mixed-breed dogs were most commonly represented. Subjectively decreased globe retropulsion and conjunctival or periorbital swelling (23/25 [92%] dogs each) were the most common clinical signs, with no vision deficits in any patient. The zygomatic gland was mainly affected (23/25 [92%] dogs), followed by parotid and mandibular glands (1 [4%] dog each). The condition was unilateral in 22 (88%) dogs. Ultrasonography (19/25 [76%] dogs), MRI (14 [56%]), fine-needle aspiration (20 [80%]), and biopsy (4 [16%]) were performed; however, the condition was deemed idiopathic in 22 (88%) dogs. Most IINACs were performed with local anesthesia (median volume, 5 mL/gland; range, 1.5 to 9 mL). No complications were identified. Other treatments included antimicrobials and anti-inflammatories. Mean follow-up time was 18.8 months. All recurrences (5/23 [22%] dogs) were controlled with medical management.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested noninvasive IINAC may be a useful adjunctive treatment for sialoceles in dogs. The procedure was easily and safely performed with local anesthesia (or general anesthesia with concurrent diagnostic imaging) in these dogs.

Exophthalmos associated to orbital zygomatic mucocele and complex maxillary malformation in a puppy

A case of exophthalmos due to zygomatic mucocele in a puppy with ipsilateral segmental maxillary atrophy is reported. A 7-month-old, mixed breed, male dog suffered the sudden-onset of unilateral painful exophthalmos and a gradual swelling of the right temporal region. A compressing, right retrobulbar mass was observed by ultrasound. Computed tomography revealed a large multiloculated cyst-like lesion of the right zygomatic gland projecting into the orbital space, thus displacing the eyeball. The ipsilateral molar part of the maxillary bone was underdeveloped, besides showing crowded, abnormal, multiple, unerupted maxillary molar teeth in the caudal maxillary region. Modified lateral orbitotomy and a selective caudal maxillary bone access were performed. The cyst-like lesion was removed and the zygomatic gland and the wall was collected for histology, which confirmed the mucocele. Clinical and imaging examinations six months after surgery showed neither recurrence of the mucocele nor ocular abnormalities. A possible common pathogenic mechanism involving these two conditions could be hypothesized.

Clinical, computed tomographic, magnetic resonance imaging, and histologic findings associated with myxomatous neoplasia of the temporomandibular joint in two dogs

CASE DESCRIPTION A 15-year-old neutered female mixed-breed dog (dog 1) and an 11-year-old neutered female Labrador Retriever (dog 2) were examined because of unilateral exophthalmus, third eyelid protrusion, and periorbital swelling that failed to respond to antimicrobial treatment. CLINICAL FINDINGS Both dogs underwent ultrasonographic, CT, and MRI examination of the head. In both dogs, advanced imaging revealed a poorly defined, peripherally contrast-enhancing, mucous-filled cystic mass that radiated from the temporomandibular joint and infiltrated the periorbital tissues and retrobulbar space. Both dogs underwent surgical biopsy of the periorbital mass. A viscous, straw-colored fluid was aspirated from the retrobulbar region in both dogs. The initial histologic diagnosis for dog 1 was zygomatic sialadenitis and sialocele. However, the clinical signs recurred, and histologic examination of specimens obtained during a second surgical biopsy resulted in a diagnosis of myxoma. The histologic diagnosis was myxosarcoma for dog 2. TREATMENT AND OUTCOME In both dogs, clinical signs recurred within 2 weeks after surgery and persisted for the duration of their lives. Dog 1 received no further treatment after the second surgery and was euthanized 34 months after initial examination because of multicentric lymphoma. Dog 2 was treated with various chemotherapy agents and was euthanized 11 months after initial examination because of a dramatic increase in periocular swelling and respiratory stertor. CLINICAL RELEVANCE Temporomandibular myxomatous neoplasia can be confused with zygomatic sialocele on the basis of clinical signs but has characteristic MRI features. Representative biopsy specimens should be obtained from areas close to the temporomandibular joint to avoid misdiagnosis.

Management of Orbital Diseases

Orbital diseases are common in dogs and cats and can present on emergency due to the acute onset of many of these issues. The difficulty with diagnosis and therapy of orbital disease is that the location of the problem is not readily visible. The focus of this article is on recognizing classical clinical presentations of orbital disease, which are typically exophthalmos, strabismus, enophthalmos, proptosis, or intraconal swelling. After the orbital disease is confirmed, certain characteristics such as pain on opening the mouth, acute vs. chronic swelling, and involvement of nearby structures can be helpful in determining the underlying cause. Abscesses, cellulitis, sialoceles, neoplasia (primary or secondary), foreign bodies, and immune-mediated diseases can all lead to exophthalmos, but it can be difficult to determine the cause of disease without advanced diagnostic imaging, such as ultrasound, magnetic resonance imaging, or computed tomography scan. Fine-needle aspirates and biopsies of the retrobulbar space can also be performed.

Clinical and ultrasonographic characteristics of salivary mucoceles in 13 dogs

Salivary mucocele is one of the causes of submandibular swelling in dogs and is due to a collection of mucoid saliva that has leaked from a damaged salivary gland. The purpose of this case series report was to describe the clinical and ultrasonographic characteristics of confirmed salivary mucoceles in 13 dogs admitted to the Faculty of Veterinary Medicine at Cairo University. The final diagnosis of salivary mucocele was based on aspirate cytology for all dogs and additional surgical excision for seven dogs. For dogs admitted from 2 weeks to 1 month from the onset of clinical signs, the cervical mucocele appeared as a round echogenic structure with a large volume of central anechoic content. The wall was a clearly identified hyperechoic structure surrounding the gland. For dogs admitted between 1 to 2 months from the onset of clinical signs, the volume of anechoic material appeared less than that seen in the acute cases. The overall appearance of the salivary mucocele was heterogenous. For dogs admitted after 2 months from the onset of clinical signs, the salivary mucocele appeared grainy or mottled, with a heterogenous appearance and a further decrease in anechoic content. For one dog that presented after 3 months from the onset of clinical signs, the salivary mucocele was hard on palpation and appeared hyperechoic with distal acoustic shadowing. Findings from this study indicated that ultrasonographic characteristics of salivary mucoceles in dogs vary depending on the chronological stage of the disease.