solitary cervical cysts

Etiology

 branchial cleft cyst (BCC)

• The most-common variety of solitary cervical cystic lesion is the branchial cleft cyst (BCC), which can become malignant.

 cervical cystic squamous cell carcinoma

• The majority of previously suspected BCCCs were actually metastatic cystic lymph nodes; misdiagnosis can occur due to the absence of long-term follow-up.

 solitary metastatic cystic lymph node
 * Thus, solitary metastatic cystic lymph nodes, from carcinomas of the upper aerodigestive tract, are difficult to differentiate from BCCCs, especially in patients more than 40 years of age.

• The proportion of metastatic cystic SCCs initially diagnosed as BCCs, or BCCCs, ranges between 11% and 21%.
• Metastatic cystic SCCs in the upper lateral neck are easily mistaken for BCCCs if the primary site of the carcinoma is not detected.
• The majority of metastatic cervical lymph nodes in head-and-neck squamous cell carcinomas (HNSCCs) are solid masses. However, between 33% and 62% of cases are cystic metastatic squamous cell carcinomas (SCC).
• The challenge, therefore, is to distinguish BCCC from occult metastatic cystic SCC, and to identify the primary site of metastatic cystic SCC in the head and neck.

 papillary thyroid carcinoma (PTC) presenting as a lateral neck cyst

References

 Differential diagnosis of cystic neck lesions. Sira J, Makura ZG.
Ann Otol Rhinol Laryngol. 2011 Jun;120(6):409-13.
PMID: 21774450