The soft tissue opacity in the cranial mediastinum may originate from thymus, lymph node, or ectopic thyroid tissue. Differentials should include neoplasia, cyst (branchial or idiopathic mediastinal), granulomatous disease, abscess, or hematoma.
Findings consistent with cyst in the mediastinum which may be mediastinal cyst or branchial cyst.
Acellular with low specific gravity. Results consistent with idopathic mediastinal cyst.
L. Armbrust, DVM, 2nd year Radiology Resident
Post ultrasound guided cyst aspirate