Hygroscopic sonographically detectable clips form characteristic breast and lymph node pseudocysts

Abstract

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.

The Curious Case of Pseudocysts in Breast Cancer Specimens: An Alteration Associated With Hydrogel-Based Breast Biopsy Markers

“…Due to these unusual findings, we discussed with a surgeon of our multidisciplinary team what type of material was being used, that could be related to those alterations. Together, and after literature research, 1 we came to the conclusion that such pseudocysts corresponded to a foreign body reaction to hydrogel-based, detectable breast biopsy markers. The histological pseudomucinous content, observed within the pseudocysts, correlates to the hydrogel component.…”

Neoadjuvant Chemotherapy for Breast Cancer: Moving Beyond Pathological Complete Response in the Molecular Age

“…Placement of fiducial marker clips at the time of diagnosis is extremely helpful in localising the tumour bed when there is no gross residual lesion, and is recommended even in patients planned for mastectomy to aid localisation of the tumour bed (67). Gel foam or larger metallic clips may be seen on slicing; gel foam clips appear as a cyst filled with gelatinous substance (68). Alternatively, the markers can be identified on x-ray of the specimen slices.…”

Intraductal Migration of a Breast Tissue Marker Placed Under Ultrasound Guidance during COVID-Induced Delay of Surgery

“…Many types of breast markers are commercially available with different sizes, shapes, and compositions. The most common materials are made of metal and embedded in hygroscopic material [ 6 ]. HydroMARK ® (Mammotome, Cincinnati, OH, USA) is of this type.…”

“…It is composed of titanium or stainless steel embedded in a hydrophilic hydrogel. The metal component is permanently visible under conventional radiography and magnetic resonance imaging (MRI), and measures approximately 2 mm [ 6 ]. Hydrogels expand after placement by absorbing water and are then degraded via hydrolysis over time.…”