Pathological examination of sentinel lymph node in breast cancer: potential problems and possible solutions

Minimal Involvement of Sentinel Lymph Node in Breast Carcinoma: Prevailing Concepts and Challenging Problems

Sentinel lymph node biopsy has attained “standard of care” status in the management of breast carcinoma. However, the pathological interpretation and clinical consequences of “minimally involved” sentinel lymph nodes remain controversial. Herein, we present some of the complex and challenging pathological problems inherent in this evolving setting. Clearly, at least some of our current concepts regarding “minimally involved” sentinel lymph nodes need reappraisal.

Sentinel lymph nodes in breast cancer after 10 years: rethinking basic principles

New techniques and treatments in medicine occasionally take on a life of their own. Sometimes, an idea's use is inherently obvious from the outset, sometimes not, in which case it becomes technology in search of an application. Identification of sentinel lymph nodes in breast cancer is a combination of these two options: to some extent the technique has been overused and its results overinterpreted. 10 years after the procedure's introduction and general acceptance, a few issues still deserve further discussion despite much published work on this topic. Use of sentinel-lymph-node identification has been extended to other organ systems, yet not all the lessons learned in the breast might apply to other sites. Review of the theory behind the technique and breast cancer experience to date is important. Many of the published controversies about sentinel lymph nodes in breast cancer can be resolved by consideration of the basic ideas underlying the procedure, which is the aim of this Essay.

Surgical pathological staging of breast cancer by sentinel lymph node biopsy with special emphasis on the histological work-up of axillary sentinel lymph nodes

Axillary nodal status assessed by traditional histological methods is a proven independent prognostic factor in breast cancer. Sentinel lymph node biopsy is a surgical pathologic staging procedure that not only allows the selective removal of the most likely sites of lymphogenic metastases, but also enables upstaging of breast carcinoma by detecting nodal involvement undetected by standard methods of nodal staging. This review highlights the upstaging potential of sentinel node biopsy. It also suggests that incomplete reporting of the pathological methods may make the comparisons of results from different studies difficult. The article also describes a few methods that have been claimed optimal but are probably not, and it formulates basic considerations for building up a histological protocol that can identify all metastases larger than 2 mm, which are of unquestionable prognostic relevance. These considerations are also useful for the detection of micrometastases. Issues of pathological reporting of sentinel nodal findings are also highlighted, with emphasis on the lack of standardization and on the differentiation of isolated tumor cells from micrometastases. Finally the stepwise building up of our current histology protocol and our experience gained since the introduction of sentinel node biopsy in 1997 is also briefly summarized.

Evolving entities and changing concepts in breast pathology

Among the evolving entities and changing concepts in breast pathology are those relating to columnar cell hyperplasia, pseudoangiomatous stromal hyperplasia, mucocele-like lesions, pleomorphic lobular carcinoma in situ, pseudo-Paget's disease of nipple, microinvasive carcinoma of breast, spindle cell metaplastic carcinoma, and minimal metastatic disease in axillary lymph nodes. Pathologists, as well as physicians involved in the management of breast diseases, need to be aware of these recent developments in breast pathology since the recognition and understanding thereof may have considerable clinical relevance.

The need for vigilance in the pathologic evaluation of sentinel lymph nodes: a report of two illustrative cases

The advent of sentinel lymph node (SLN) biopsy for breast cancer has had a considerable impact on clinical oncology. The SLN procedure has been widely adopted, but major clinical issues remain unresolved pending the outcome of randomized trials. Pathologic handling of SLNs is less controversial; however, significant pitfalls in their handling have been reported. Herein we report two additional uncommon situations that demonstrate the need for the utmost vigilance in both the macroscopic examination (i.e., trimming of "positive" nodal tissue) and microscopic examination (i.e., presence of nevus cell aggregates mimicking metastatic carcinoma) of SLN specimens.