Glandular structures in an intraoperative axillary sentinel lymph node biopsy: a diagnostic dilemma

Presence of Basement Membrane Material around the Tubules of Tubulolobular Carcinoma

BACKGROUND: Core needle biopsies represent only a small portion of a breast lesion. Rare lesions with overlapping features may be underestimated in such small samples. CASE REPORT: A 67-year-old female underwent core needle biopsy of a 27-mm breast tumour demonstrating infiltrative glands without significant desmoplasia. Periglandular collagen IV immunostaining and the small glands were reminiscent of microglandular adenosis, and despite the infiltrative look of the microglands, the lesion was interpreted as suspicious for malignancy. Finally, the tumour proved to be a tubulolobular carcinoma. CONCLUSIONS: The tubules of tubulolobular carcinoma may show a basement membrane-like staining pattern with collagen IV, and this must be considered in the differential diagnosis of mammary lesions with small glandular architecture.

Lobular neoplasia diagnosed at core biopsy does not mandate surgical excision

BACKGROUND

Lobular intraepithelial neoplasia (LIN) is associated with an increased risk of breast malignancy. The significance of LIN diagnosed at core needle biopsy (CNB) is unclear, although many groups recommend surgical excision to rule out lesions, which would require immediate, definitive therapy. Current management options include clinical/mammographic observation and surgical excision. The necessity of routine surgical excision remains controversial due to conflicting opinions on the biological behavior of lobular lesions, diagnostic confusion regarding histopathology, and uncertainty of their association with high-risk lesions. The purpose of this report was to review the published data regarding the incidence of high-risk lesions associated with LIN diagnosed at CNB to clarify the indications for surgical excision.

MATERIALS AND METHODS

A PubMed search was performed to identify all published articles in English addressing management of LIN diagnosed at CNB.

RESULTS

The 19 studies that form the basis of this report included a total of 504 subjects. Although the studies differed greatly in their content and methods, they were analyzed as a group for the presence of criteria deemed by the authors to be the most important information to include in a study regarding this issue and thus a reasonably good indicator of the quality of the literature. All of the studies were retrospective, nearly half were nonconsecutive series, and no study reported clear inclusion criteria for surgical excision versus observation. Limitations of the reviewed studies included their retrospective nature, small number of subjects, inconsistent inclusion criteria, and selection bias regarding surgical excision.

CONCLUSIONS

Based on the reviewed literature, it is difficult to reach a firm evidence-based conclusion regarding optimal management of LIN diagnosed at CNB. Associated high-risk lesions increase the risk of upgrade, but there are no mammographic predictors. The available retrospective literature suggests that some cases of LIN are associated with higher-risk lesions identified on surgical excision but does not support routine excision for all patients.

Pathological Evaluation of Sentinel Lymph Nodes

The sentinel lymph nodes are the most likely site of nodal metastasis. Their focused analysis results in upstaging cancers, although the extra yield from a more intensive work-up is generally dominated by micrometastases and isolated tumor cells. Nodal staging is generally done to reflect systemic spread of solid tumors and guide treatment accordingly. However, in general, the two processes of haematogenous and lymphogenic spread are not causally interrelated, and the extrapolation from low-volume nodal involvement to systemic involvement and therapeutic consequences of this extrapolation are still under investigation.