to the editor: I enjoyed the article “Breast Cyst Aspiration,”¹ in the November 15, 2003, issue of American Family Physician. As a diagnostic radiologist, I’ve aspirated thousands of breast cysts and would like to offer a few suggestions regarding the management of cysts.

I think the aspiration technique is even simpler than the authors¹ indicate. By cleansing the skin that will be punctured by the needle with two or three alcohol wipes, povidone-iodine swabs or sterile drapes are not necessary.

There is fairly good evidence^2–4 that injecting an equivalent volume of air into the cyst after aspirating the fluid prevents or markedly reduces the propensity for cyst fluid reaccumulation. Desiccation of the fluid-secreting cells that line the cyst interior has been proposed as the mechanism. The air injection is accomplished by unscrewing the syringe from the needle with the needle in situ, evacuating the aspirated cyst’s fluid from the syringe into a container or test tube, drawing an equivalent volume of air back into the syringe, reattaching the syringe, and injecting the air. This takes 20 seconds and may prevent cyst recurrence. Patients will have a soft mushy mass where the cyst had been, and the air resorbs during the ensuing days. Before ultrasonography was generally available in breast-imaging facilities, we would perform “pneumocystogram” mammography after injecting the air to exclude the possibility of intracystic mass.

In my experience, thick gelatinous cyst fluid is simply “old” fluid with high protein content. Intracystic neoplasms are papillary cancers or papillomas, and do not have this type of intracystic fluid; it is generally new or old blood resulting from spontaneous hemorrhage or local needle trauma to the friable papillary fronds that occurs during the aspiration procedure. I’ve watched numerous colloid-filled cysts completely disappear with aspiration under real-time ultrasound observation. It is okay to simply discard viscous fluid from cysts if it is not bloody. Even in the case of documented intracystic papillary cancer, the sensitivity of cytologic diagnosis from the cyst fluid is quite poor. In general, cyst fluid cytology is seldom helpful, and may even force unnecessary surgical biopsies in cases where the cytology shows “atypia.”

If no fluid is obtained during the first stick, I would urge physicians to stop and maintain firm pressure to minimize bruising, because hematomas can complicate breast imaging by obscuring true masses.

Lastly, the authors¹ note that surgical referral is recommended for refilling of cysts or residual mass after aspiration. Actually, breast imaging is the most logical next step. A work-up would include a diagnostic mammogram following placement of a metallic marker over the palpable finding, and an ultrasound examination of the region using current-generation equipment. Only after a thorough imaging evaluation should the need for tissue sampling be addressed. The radiologist usually should decide whether or not tissue diagnosis is needed. If tissue sampling is needed, it could be done with core needle biopsy at the time of the diagnostic mammogram, and all data necessary for management would be obtained during one visit to the radiology department.

editor’s note : This letter was sent to the authors of “Breast Cyst Aspiration,” who declined to reply.