Hygroscopic sonographically detectable clips form characteristic breast and lymph node pseudocysts.

The use of hygroscopic sonographically detectable clips (HSDCs) has dramatically increased during the last years, especially in breast cancer patients who undergo neoadjuvant chemotherapy. The aims of this study are to define the appearance of HSDC sites in histopathological specimens, and to enable pathologists to recognize these sites and differentiate them from other lesions. We examined 124 breast cancer specimens in which the application of HSDCs was documented, 88 breast tissues and 36 lymph nodes, and analyzed the appearance of the clip site in these tissues. The clip site was clearly detected histologically in 79/88 (90%) of the breast specimens and in 29/36 (81%) of lymph node specimens. In most of the specimens, the HSDC site had a specific characteristic appearance of a pseudocyst, lined by layers of epithelioid histiocytes, sometimes with pseudopapillary formation, and with minimal or no fibrosis. This was the appearance in 69 of the breast specimens and in 23 of the lymph node specimens. In other specimens, scarring, scattered foamy macrophages and abundant siderophages were the predominant findings, as usually found in sites of other clips. As non-palpable breast lesions become more frequent, clips play a major role in the treatment of breast cancer, making them an important component of the communication among radiologists, surgeons, pathologists, and oncologists. HSDCs in tissues have a characteristic appearance with an epithelioid component. Pathologists should be able to recognize this finding, differentiate it from other breast lesions and include it in the pathology report.

Detectability of Hygroscopic Clips Used in Breast Cancer Surgery.

Sonographically detectable clips were introduced over the last decade. We retrospectively studied the rate and duration of sonographically detectable clip detectability in patients with breast cancer who had sonographically detectable clips inserted over a 2-year period. Nine of 26 patients had neoadjuvant chemotherapy, with all clips remaining detectable 140 to 187 days after insertion. Six of the 9 had intraoperative sonographic localization, with 1 reoperation (17%). Eleven additional patients with nonpalpable tumors and sonographically detectable clips had intraoperative sonographic localization with 1 reoperation (9%). In 1 patient, a sonographically detectable clip enabled intraoperative identification of a suspicious lymph node. There were no complications or clip migration. Sonographically detectable clips are helpful in breast cancer surgery with and without neoadjuvant chemotherapy, remaining detectable for many months and often averting preoperative localization and scheduling difficulties.