MRI Assessment of Right Lower Neck Cystic Lesion
This MRI finding is NOT consistent with a hemangioma and requires further diagnostic workup with contrast-enhanced imaging to characterize this cystic neck mass.
Why This is Not a Hemangioma
The described imaging characteristics are fundamentally incompatible with hemangioma:
- Hemangiomas demonstrate markedly hyperintense T2 signal with intermediate T1 signal intensity, not the described T1 hypointense/T2 hyperintense cystic appearance 1, 2
- Hemangiomas are solid vascular lesions that show avid enhancement with contrast, demonstrating either peripheral nodular enhancement with centripetal filling or diffuse enhancement similar to adjacent vessels 2, 3
- The presence of internal septations within a cystic lesion is characteristic of truly cystic masses or cystic-appearing solid tumors, not typical hemangiomas 4
Critical Imaging Features Present
Your lesion demonstrates:
- Well-circumscribed cystic morphology with internal septation measuring 3.7 x 1.8 cm 4
- T1 hypointense, T2/FLAIR hyperintense signal consistent with fluid content 4
- Location in right lower neck above lateral clavicle at T1-T2 level
- Associated bilateral level I cervical lymphadenopathy (sub-centimeter nodes)
Differential Diagnosis to Consider
This imaging pattern suggests:
- Cystic hygroma (lymphangioma) - most common cystic neck mass with septations in this location
- Branchial cleft cyst - though typically more anterior
- Cystic schwannoma or neurofibroma - peripheral nerve sheath tumors can show bright T2 signal and cystic degeneration 4
- Cystic metastatic lymph node - particularly given the bilateral cervical lymphadenopathy
- Venous malformation - low-flow vascular malformation can appear cystic
Mandatory Next Steps
Contrast-enhanced MRI is essential to distinguish truly cystic lesions from solid masses with cystic degeneration 4:
- If no internal enhancement is present → likely truly cystic lesion (lymphangioma, branchial cleft cyst)
- If wall thickening, nodules, or internal enhancement is present → solid lesion must be suspected and biopsy considered 4
- Evaluate for "split fat sign," "string sign," or "target sign" which would suggest peripheral nerve sheath tumor 4
Critical Pitfall to Avoid
Do not assume this is benign without contrast enhancement evaluation. Solid malignant masses including synovial sarcomas, myxofibrosarcomas, and soft-tissue metastases can exhibit bright T2 signal simulating a cyst 4. The presence of bilateral cervical lymphadenopathy, though sub-centimeter, raises concern for potential malignancy and mandates thorough characterization.