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

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.

Fine-needle aspiration diagnosis of lymphomas with signet ring cell features: potential pitfalls and solutions

BACKGROUND

Lymphoma with signet ring cell features (LSF) is a rare morphologic variant of non-Hodgkin lymphoma. Although it has been well documented in the surgical pathology literature, to the best of the authors's knowledge, the features of LSF in fine-needle aspiration (FNA) samples have rarely been reported. An accurate cytologic diagnosis of LSF is of important therapeutic significance.

METHODS

The authors retrospectively reviewed 7 FNA cases of LSF for cytologic features, ancillary studies, corresponding histologic findings, and the patients' clinical and radiologic information to illustrate the diagnostic clues and potential pitfalls.

RESULTS

The final diagnoses, based on a multidisciplinary approach, were follicular lymphoma (5 patients), large B-cell lymphoma of follicular center cell origin (1 patient), and low-grade B-cell lymphoma with plasmacytoid features (1 patient). FNAs were obtained from both lymph node and extranodal sites. Common cytologic features included various percentages of signet ring cells in a background of nonvacuolated lymphomatous cells, lymphoglandular bodies, and cytoplasmic rings. The majority of signet ring cells contained a single, large, clear intracytoplasmic vacuole that pushed the nucleus laterally whereas fewer cells contained ≥ 2 vacuoles that indented the nucleus into a scalloped or stellate configuration. These cells resemble, to some degree, other lesions with signet ring cell features. One of the diagnostic clues of LSF was the similarity in nuclear details between signet ring cells and surrounding nonvacuolated lymphoid cells.

CONCLUSIONS

Familiarity with cytologic features, correlation with clinical/radiologic information, and ancillary studies are important for an accurate diagnosis of LSF and for distinguishing it from other lesions with signet ring cell features in FNA samples.

Primary Mucinous Cystadenocarcinoma of the Breast: Cytologic Finding and Expression of MUC5 Are Different from Mucinous Carcinoma

Mucinous cystadenocarcinoma (MCA) in the breast is a rare neoplasm. There have been 13 cases of primary breast MCA reported. The MCA presents as a large, partially cystic mass in postmenopausal woman with a good prognosis. The microscopic findings resemble those of ovarian, pancreatic, or appendiceal MCA. The aspiration findings showed mucin-containing cell clusters in the background of mucin and necrotic material. The cell clusters had intracytoplasmic mucin displacing atypical nuclei to the periphery. Histologically, the tumor revealed an abundant mucin pool with small floating clusters of mucin-containing tumor cells. There were also small cysts lined by a single layer of tall columnar mucinous cells, resembling those of the uterine endocervix. The cancer cells were positive for mucin (MUC) 5 and negative for MUC2 and MUC6. This mucin profile is different from ordinary mucinous carcinoma and may be a unique characteristic of breast MCA.

Diagnostic value of fine-needle aspiration biopsy for breast mass: a systematic review and meta-analysis

BACKGROUND

Fine-needle aspiration biopsy (FNAB) of the breast is a minimally invasive yet maximally diagnostic method. However, the clinical use of FNAB has been questioned. The purpose of our study was to establish the overall value of FNAC in the diagnosis of breast lesions.

METHODS

After a review and quality assessment of 46 studies, sensitivity, specificity and other measures of accuracy of FNAB for evaluating breast lesions were pooled using random-effects models. Summary receiver operating characteristic curves were used to summarize overall accuracy. The sensitivity and specificity for the studies data (included unsatisfactory samples) and underestimation rate of unsatisfactory samples were also calculated.

RESULTS

The summary estimates for FNAB in diagnosis of breast carcinoma were as follows (unsatisfactory samples was temporarily exluded): sensitivity, 0.927 (95% confidence interval [CI], 0.921 to 0.933); specificity, 0.948 (95% CI, 0.943 to 0.952); positive likelihood ratio, 25.72 (95% CI, 17.35 to 28.13); negative likelihood ratio, 0.08 (95% CI, 0.06 to 0.11); diagnostic odds ratio, 429.73 (95% CI, 241.75 to 763.87); The pooled sensitivity and specificity for 11 studies, which reported unsatisfactory samples (unsatisfactory samples was considered to be positive in this classification) were 0.920 (95% CI, 0.906 to 0.933) and 0.768 (95% CI, 0.751 to 0.784) respectively. The pooled proportion of unsatisfactory samples that were subsequently upgraded to various grade cancers was 27.5% (95% CI, 0.221 to 0.296).

CONCLUSIONS

FNAB is an accurate biopsy for evaluating breast malignancy if rigorous criteria are used. With regard to unsatisfactory samples, futher invasive procedures are required in order to minimize the chance of a missed diagnosis of breast cancer.