Cervical Mass in a Dog.

Patient Information:

Age: 10-year old
Gender: Neutered Male
Species: Canine
Breed: Saluki

History and clinical findings:

The owner noticed an area of swelling on right proximo-lateral cervical region one week prior to presentation which had tripled in size and was painful on palpation. The patient had a right thyroid gland carcinoma removed 3 months prior to presentation.

Ultrasound Interpretation:

The right mandibular salivary gland (MSG) was moderately enlarged (2.3x3.7cm in diameter) and had a slightly heterogenous hyperechoic echogenicity when compared to the left MSG. A well-defined thin-walled area containing anechoic fluid and flocculent hyperechoic particles/debris was seen extending from the right MSG measuring 2.1x5.2cm in diameter. No evidence of sialoliths was detected. The soft tissue surrounding the affected gland was diffusely moderately hyperechoic and contained a few small anechoic fluid pockets (edema). The visible retropharyngeal lymphnodes and cervical bone structures had a normal sonographic appearance.

Sampling:

Ultrasound-guided fine-needle biopsies of the affected gland and fluid samples were collected under sedation and submitted for cytology and fluid analysis.

Diagnosis:

Epithelial cell proliferation with mild atypia; mixed, predominantly neutrophilic inflammation. Viscous fluid with mixed macrophagic, neutrophilic, and lymphocytic inflammation; suspect inflamed salivary mucocele. The prior history of thyroid carcinoma and the hyperplastic epithelial proliferation were concerning for neoplasia, although some of the epithelial atypia could have been dysplastic changes secondary to the significant inflammatory process present.

Case management:

Since the patient was experiencing discomfort, surgical exploration and removal was performed. Histopathology evaluation revealed findings consistent with salivary gland mucocele formation without evidence of underlying infection or neoplasia. The patient made an uneventful and complete recovery.