8-year-old castrated male Husky
2017 Image Interpretation - Case 8
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- Presented for swelling under jaw.
- Previously aspirated and suspected to be a salivary mucocele.
- Progressive dyspnea, difficulty swallowing and change in bark recently.
- Large, irregularly shaped, fluid filled cystic area ventral to the cranial cervical spine.
- Relatively high signal intensity on T2/STIR. Septae within the mass are T2 low signal.
- Apparently portions of it contrast enhance (or contrast leaking into it) on MR, but not on CT.
- Possible non-contrasting mass on the right side inside the cystic region (muscle belly most likely, clot or tumor less likely).
- Lysis of the ventral aspect of C1.
- Ventral and rightward deviation of trachea and esophagus (which is also compressed), ventral displacement of the soft palate.
- Connection between ventral C1 and the fluid filled mass.
- Mass appears to enter or communicate with the epidural space at C1/C2 and extends rostrally along the ventral aspect of spinal canal to the level of the foramen magnum.
- Moderate synovial fluid accumulation and bulging of joint capsule around the dorsal articular facets of AO joint and C1 – C2.
- Neoplasia
- Primary tumor of C1.
- Some sort of soft tissue neoplasia.
- Acquired
- Mengiocele.
- Synovitis of some type with overproduction of synovial fluid.
- Pharyngeal cyst with secondary necrosis and lysis of C1.
- Chronic migrating foreign body with cyst/abscess.
- Trauma
- Previous trauma to C1/C2 resulting in CSF or synovial fluid leakage.
- Synovial Myxosarcoma (low grade).
- Surgically debulked then had radiation therapy. Did well following surgery.