Cyst diagnosis by visual inspection
Depending upon the type and location of a cyst, diagnosis may be simple or difficult. Sometimes a cyst is visible as a lump or bump underneath the skin. Some ganglion cysts, sebaceous cysts, thyroid cysts, pilonidal cysts, and Baker cysts are examples of cysts that may be apparent on visual inspection and physical examination.
Imaging studies to diagnose cysts
Sometimes, cysts are diagnosed when imaging tests are being done for another reason or to investigate unexplained symptoms. CT and MRI scans can often reveal cysts even if they did not cause symptoms. For example, ovarian cysts or cysts of the kidneys, pancreas, or liver are typically not apparent on physical examination. Ultrasound examination can reveal cysts of the breasts or other organs.
Benign vs. malignant cysts
The vast majority of cysts are benign. In rare cases, cysts can be associated with a cancer. If there is concern that a cystic structure may be part of a cancerous tumor, a biopsy is typically performed. In many cases, the biopsy involves removal of the cyst fluid by a thin needle, a procedure known as fine-needle aspiration (FNA). The fluid is then examined for the presence of malignant cells. Ultrasound or other imaging studies may be done at the time of FNA to ensure the needle is placed correctly into the cyst. In other cases, surgical removal of all or part of a cyst is carried out to obtain tissue for analysis.
Medically reviewed by John A. Daller, MD; American Board of Surgery with subspecialty certification in surgical critical care
Johnson, Jonas T. "Fine-Needle Aspiration of Neck Masses." Medscape.com. Apr. 25, 2012. <http://emedicine.medscape.com/article/1819862-overview>.