Diagnostic significance of 'benign pairs' and signet ring cells in fine needle aspirates (FNAs) of the breast

Mammary mesenchymal and fibroepithelial lesions: An illustrated cytomorphologic update with differential diagnoses

The Uniform Approach to Breast Fine Needle Aspiration Biopsy was put forward by a learned group of breast physicians in 1997. This landmark manuscript focused predominantly on diagnosis and reporting of mammary epithelial lesions. Today, most American practitioners turn initially to core biopsy rather than aspiration biopsy for the first line diagnosis of solid breast lesions; however, recent efforts from the International Academy of Cytology have produced a system called the Standardized Reporting of Breast Fine Needle Aspiration Biopsy Cytology (colloquially labeled in 2017 as the "Yokohama System"), suggesting a new interest in breast fine needle aspiration (FNA), especially in resource limited settings or clinical practice settings with experienced breast cytopathologists. Fibroepithelial lesions of the breast comprise a heterogeneous group of biphasic tumors with epithelial and stromal elements. Mesenchymal lesions of the breast include a variety of neoplasms of fibroblastic, myofibroblastic, endothelial, neural, adipocytic, muscular, and osteo-cartilaginous derivations. The cytology of mesenchymal breast lesions is infrequently described in the literature and is mainly limited to case reports and small series. This illustrated review highlights the cytologic features of fibroepithelial and mesenchymal mammary proliferations and discusses differential diagnoses and histomorphologic correlates.

Prognostic significance of mucin expression profiles in breast carcinoma with signet ring cells: a clinicopathological study

Background

Signet ring cells (SRCs) often accompany gastrointestinal carcinoma, referred to as SRC carcinoma; however, breast cancers containing SRCs have not been well characterized, leaving the prognostic significance of SRCs undetermined. We have described clinicopathological characteristics of patients with breast cancer containing SRCs in relation to the expression levels of MUC1, MUC2, MUC4, MUC5AC, and MUC6.

Methods

Twenty-two breast cancer cases with variable degrees of SRC population were retrospectively studied. Each case was categorized as high (>31 %) or low (<30 %) SRC tumor. The SRCs were morphologically classified into the intra-cytoplasmic lumen (ICL) type, or the non-ICL type. The expression levels of MUC1, MUC2, MUC4, MUC5AC and MUC6 were determined immunohistochemically. Depending on its subcellular localization, MUC1 was categorized as the luminal and cytoplasmic (LC) type, or the cytoplasmic with circumferential membranous accentuation (CM) type. These histological findings were compared with other clinicopathological parameters.

Results

The series consisted of invasive ductal carcinoma (n = 9), invasive lobular carcinoma (n = 9), and mucinous carcinoma (n = 4) cases. The SRC population accounted for 8–81 % of the tumor cells. Eight cases had ICL type SRCs, and the remaining 14 had non-ICL type SRCs. Neither the high (n = 12) and low (n = 10) percentage of SRCs, nor the SRC types affected the clinicopathological parameters. In the low MUC1 group (n = 11), larger tumors, higher nuclear grade, lymph node metastasis, and negativity for estrogen receptor was more frequently identified compared to the high MUC1 group (n = 11; p = 0.01, p = 0.002, p = 0.008, and p = 0.02, respectively). The CM group (n = 7) had more patients with large-sized tumors, lymph node metastasis, lymphovascular invasion, and higher Ki67 indices than the LC group (n = 15; p = 0.04, p = 0.001, p = 0.006, and p = 0.03, respectively). The expression levels of MUC2, MUC4, MUC5AC, and MUC6 showed no clinicopathological significance. Two patients with low MUC1 expression and CM patterns had tumor recurrence, resulting in death, while all the other patients survived without recurrence.

Conclusion

Our results demonstrate that in breast cancers containing SRCs, low MUC1 expression and/or its CM subcellular localization patterns are associated with unfavorable clinicopathological factors. The utility of MUC1 expression as a prognostic marker remains to be verified in future studies.

Benign pairs: a significant entity in aspiration cytology smears from breast lesions

INTRODUCTION

Fine needle aspiration cytology (FNAC) is a reliable diagnostic tool used to diagnose breast lesions preoperatively. However, FNAC is also associated with diagnostic pitfalls. Further studies are needed to improve its diagnostic efficacy. We noticed ovoid, bare nuclei arranged in closely touching diads (benign pairs) in a significant number of cytology smears. This prompted us to assess their diagnostic utility.

MATERIALS AND METHODS

This was a prospective study conducted in Sarojini NaiduMedical College, Agra, India. Quantitative estimation of benign pairs per 1000 ductal cells in at least 20 high power field was attempted in cytology smears of 128 cases.

RESULTS

The average number of pairs in benign and malignant lesions was calculated as 7.07 + 5.96 and 0.28 + 0.78, respectively. Statistical analysis showed a significant difference between the number of pairs in benign and malignant cases (P < 0.0005).

CONCLUSIONS

Quantitative estimation of benign pairs is helpful in distinguishing benign from malignant cases.

Signet ring cells in fine needle aspiration cytology of breast carcinomas: review of the cytological findings in ten cases identified by histology

OBJECTIVE

To establish whether the presence of signet ring cells (SRCs) in histology sections of breast carcinoma cases was reflected by their presence in fine needle aspiration cytology (FNAC) smears, correlating to the histological type of breast carcinoma.

METHODS

We reviewed the FNAC findings of ten cases that had been diagnosed as primary breast carcinoma with SRCs on histological sections between 1998 and 2007. Slides and histological sections were obtained from the archives of Ege University Hospital.

RESULTS

FNA smears were reviewed for the following cytomorphological features: background, cellularity, architecture, nuclear pleomorphism and the presence of SRCs. The background was bloody in eight cases, necrotic in one, and clean in one. There was no mucinous material in any of the cases. Cellularity was prominent in five cases (hypercellular), moderate in three (cellular) and low in two (hypocellular). Loosely cohesive groups of tumour cells of varying size were observed in all cases. A plasmacytoid appearance to some of the tumour cells was seen in all cases and discohesive tumour cells were present in eight. Nuclear pleomorphism was high in six cases and moderate in four. SRCs were observed in seven of the ten cases. Two of these seven cases also had a tubular pattern and one had tumour giant cells.

CONCLUSIONS

FNAC should be evaluated carefully regarding the presence of SRCs when cells with a plasmacytoid appearance are observed in either hyper- or hypocellular smears. The presence of single SRCs in FNACs with hypercellularity, high nuclear grade and tubular formation or tumour giant cells may be a clue in favour of ductal carcinoma. The presence of single SRCs in FNACs with hypocellularity and mild to moderate nuclear grade may be suggestive of lobular carcinoma. However, larger studies would be needed to establish the predictive value of the presence of SRCs on FNAC.

The importance of intracytoplasmic DPAS positivity in fine needle aspirates of breast lesions

AIMS

For many years the presence of strong intracytoplasmic periodic acid Schiff (PAS) positive, diastase resistant (DPAS) staining within atypical cells has been used in this laboratory as a marker for carcinoma in fine needle aspirates from breast lesions. The aim of the current study was to document such DPAS positivity across the spectrum from benign to malignant breast disease and assess its value in the upgrading of cytology reports.

METHODS

Over a six month period, 315 aspirates were studied, each having sufficient cellular material for DPAS staining to be carried out on one whole slide. DPAS staining was recorded semiquantitatively as negative, equivocal, or positive (+, ++, or +++). The cytology results were correlated with any subsequent histology performed on these patients.

RESULTS

DPAS positive material was seen in both intracellular and extracellular locations. Care was needed in its interpretation. Occasional cells with apparently genuine intracytoplasmic positivity (+) were found in both benign and malignant cases. Frequent or particularly strong intracellular DPAS positivity (++, +++) correlated best with malignancy. Two cases were reliably upgraded from immediate reports suspicious of malignancy to final reports diagnostic of malignancy on the basis of the intracytoplasmic DPAS staining.

CONCLUSION

Strict criteria are required for the interpretation of intracytoplasmic DPAS positivity and routine cytological appearances should also be taken into account. Weak positivity in occasional cells, especially in flat epithelial sheets, may be seen in benign lesions and is not reliable as a marker of malignancy. DPAS positivity with internal structure and producing nuclear indentation, especially in dissociated or atypical cells, correlates well with malignant histology and can be reassuring in the cytological diagnosis of malignancy.