Signet ring carcinoma of the female breast: a clinicopathologic analysis of 24 cases

Primary signet ring cell carcinoma of the breast: A case report and literature review

ABSTRACT

Primary signet ring cell carcinoma (SRCC) of the breast is a rare and aggressive type of breast cancer characterized by increased intracellular mucin production. It has a high risk of metastasis and poor prognosis compared to other breast cancer types. We report a 56-year-old woman with primary SRCC of the breast who first presented with retraction on her left breast. Radiological examination revealed a mass that causes the retraction. The patient underwent left modified radical mastectomy, and pathology results showed a 70% signet ring cell pattern. Chemotherapy consists of an adriamycin-cyclophosphamide regimen administered. in this case, we aim to review the literature on this topic and inform the physicians.

Deciphering the Clinical Behaviour of Invasive Lobular Carcinoma of the Breast Defines an Aggressive Subtype

BACKGROUND

Invasive lobular carcinoma (ILC), the most common special type of breast cancer (BC), has unique clinical behaviour and is different from invasive ductal carcinoma of no special type (IDC-NST). However, ILC further comprises a diverse group of tumours with distinct features. This study aims to examine the clinicopathological and prognostic features of different variants of ILC, with a particular focus on characterising aggressive subtypes.

METHODS

A large (n = 7140) well-characterised and histologically reviewed BC cohort with treatment and long-term follow-up data was investigated. The cohort was classified based on the WHO classification of tumours into main histological subtypes, including ILC and IDC-NST. ILCs were further classified into variants. Clinicopathological parameters and patient outcomes in terms of BC-specific survival (BCSS) and disease-free survival (DFS) were evaluated.

RESULTS

ILC constituted 11% of the cohort. The most common non-classic ILC variants were pleomorphic (pILC) and solid (sILC), constituting 19% of ILC. Compared to classic and related variants (alveolar, trabecular, papillary, and tubulolobular; cILC), pILC and sILC variants were associated with aggressive tumour characteristics. The histologic grade of ILC was an important prognostic variable. The survival patterns identified an aggressive ILC subtype encompassing pILC and high-grade sILC. These tumours, which comprised 14% of the cases, were associated with clinicopathological characteristics of poor prognosis and had high BC-specific death and recurrence rates compared not only to cILC (p < 0.001) but also to IDC-NST (p = 0.02) patients. Contrasting this, cILC patients had significantly longer BCSS and DFS than IDC-NST patients in the first 10 to 15 years of follow-up. Adjuvant chemotherapy did not improve the outcome of patients with aggressive ILC subtypes.

CONCLUSIONS

pILC and high-grade sILC variants comprise an aggressive ILC subtype associated with poor prognostic characteristics and a poor response to chemotherapy. These results warrant confirmation in randomised clinical trials.

Invasive lobular carcinoma with extracellular mucin (ILCEM): clinicopathologic and molecular characterization of a rare entity

Invasive lobular carcinoma with extracellular mucin (ILCEM) is a rare histologic subtype of breast cancer. Little is known about the pathologic or genomic signatures that distinguish ILCEM from classic invasive lobular carcinoma (ILC) or mucinous carcinoma. We studied 17 breast cancers with lobular morphology and extracellular mucin. Thirteen tumors with sufficient tissue for DNA extraction were analyzed by a next generation sequencing (NGS) assay that interrogates 447 genes for mutations and copy number variations (CNVs). Median patient age was 66 yrs (range: 31-77 yrs). Sixteen patients presented with masses, 7 of which were >2 cm. Seven patients had lymph node metastases. The cases of ILCEM were moderately (n = 13) or poorly differentiated (n = 4), frequently exhibiting variant morphology that has not been previously described or emphasized, including grade 3 nuclei (n = 11), diffuse signet ring cells (n = 10), solid growth (n = 4), tumor necrosis (n = 3) or apocrine features (n = 2). All tumors showed absent or reduced membranous E-cadherin expression. Concurrent lobular carcinoma in situ (LCIS) was seen in 11/17 cases, 1 of which was a striking example of signet ring cell LCIS with extracellular mucin. Receptor profiles were ER+/HER2- (n = 15) and ER+/HER2+ (n = 2). With a median follow-up of 83.5 months (range: 3-171 months) in 12 patients with available information, 8 patients had recurrences resulting in 4 cancer-related deaths. The most common CNVs were 16q loss (n = 11) and 1q gain (n = 9). CDH1 gene-level alterations were detected in all but one case, including frameshift (n = 7), nonsense (n = 2), and donor splice site (n = 1) mutations and indels (n = 2). Recurrent mutations were also seen in PIK3CA (n = 3), POLQ (n = 3), TP53 (n = 3), ERBB3 (n = 3), ERBB2 (n = 2), and RUNX1 (n = 2). Genes with recurrent amplifications included GATA3 (n = 4), FOXA1 (n = 3), CCND1 (n = 2). Our data highlights ILCEM as a distinct variant of ILC that often presents with higher-grade and variant morphologic features and is associated with an aggressive clinical course. NGS data support an overall lobular-type molecular profile and reveal potentially targetable alterations in a subset of cases with recurrence.

Prognostic Analysis of Primary Breast Signet Ring Cell Carcinoma and Mucinous Breast Adenocarcinoma: A SEER Population-Based Study

Background

Primary breast signet ring cell carcinoma (SRCC) is a rare type of breast cancer with typical morphological characteristics, high aggressiveness, and poor prognosis. SRCC is different from mucinous breast adenocarcinoma (MBC). However, only a few studies have explored the clinicopathological features and prognosis of SRCC and MBC.

Methods

Data retrieved from the Surveillance, Epidemiology, and End-Results (SEER) database (2004-2015) were used to explore the prognostic effect of clinicopathological features and treatment modalities on survival outcomes of SRCC and MBC patients. Kaplan-Meier plot analysis, multivariate Cox proportional risk model, propensity score matching (PSM), and subgroup analysis were performed.

Results

A total of 167 patients with SRCC and 11,648 patients with MBC were included in the study. SRCC patients exhibited higher histological grade (p < 0.001), larger tumor volume (p < 0.001), higher rate of lymph node metastasis (p < 0.001), and higher frequency of distal metastasis (p < 0.001) compared with MBC patients. Cox proportional hazards regression analysis showed that SRCC patients had lower overall survival (OS) and breast cancer-specific survival (BCSS) compared with MBC patients. Subgroup survival analysis showed that the SRCC patients had lower OS and BCSS in subgroups including younger than 60 years old, white race, married, without chemotherapy, and received radiotherapy compared with the MBC patients in these subgroups. In addition, the SRCC patients had lower BCSS in subgroups including other races (including Asian or Pacific Islander and American Indian/Alaska Native), without surgery, and lymph node metastasis.

Conclusion

The findings showed that primary breast SRCC patients have unique clinical characteristics and worse prognosis compared with MBC patients. Notably, different treatment methods resulted in different prognosis for SRCC and MBC types; therefore, SRCC patients should be distinguished from MBC patients to improve efficacy of treatment.

Prognostic Outcomes of Signet Ring Cell Carcinoma of the Breast

BACKGROUND

Signet ring cell breast carcinoma (SRCBC) is a rare variant of invasive lobular carcinoma and there are no large series characterizing its long-term prognosis.

MATERIALS AND METHODS

The NCDB was queried from 2004-2016 to identify SRCBC patients. Patients were excluded if they had non-invasive tumors, multiple malignancies, or incomplete surgical data. Univariate analysis was performed utilizing chi-squared and Fischer's Exact tests. Kaplan-Meier and Cox proportional hazard models were used for survival analysis.

RESULTS

324 patients met inclusion criteria. Patients were mostly White (75.3%), ≥50 years of age (88.2%), female (98.5%), and had a low Charlson-Deyo score (82.7%). 34.5% had Stage IV disease and 78.1% had ER+ tumors. In patients with non-Stage IV disease, 91.5% received surgery: 49.5% had lumpectomy and 50.5% underwent mastectomy. Radiation therapy was used in 40.7% (71.4% with lumpectomy and 35.8% with mastectomy) and 50% received chemotherapy. Significant differences in unadjusted overall survival were seen at 5 and 10 years based on stage (P < 0.001). On multivariate analysis, ER+ patients showed an improved survival (HR 0.5, P < 0.01) but there was no difference in survival if ER+ patients received endocrine therapy (ET) (HR 0.9, P = 0.57). Non-metastatic patients who underwent surgery had improved overall survival compared to those that did not (HR 0.5, P = 0.02), but there was no survival difference based upon type of breast operation (P = 0.8).

CONCLUSION

SRCBC frequently presents at an advanced stage. While ER+ patients appear to have improved survival, there was no clear survival benefit to receiving ET in ER+ patients.

The treatment option of progressive disease in breast cancer during neoadjuvant chemotherapy: a single-center experience

Patients' responses to breast cancer neoadjuvant chemotherapy (NACT) differ because of heterogeneous tumor characteristics. Reports about NACT progression are sporadic. Here we enrolled 1187 patients who received NACT in our cancer center between January 1, 2007, and December 31, 2016. We analyzed the characteristics and treatments of patients with progressive disease (PD) or non-PD or pathological complete response (pCR). In total, 45 (3.8%) patients had PD. PD patients were associated with a significantly worse disease-free survival (DFS) (hazard ratio (HR) = 3.77; 95% CI, 1.77 to 8.00; P =.001) and overall survival (OS) (HR = 3.85; 95% CI, 1.77 to 8.35; P =.001). For the PD patients, 28 (62.2%) patients received mastectomy immediately after PD, and 17 (37.8%) changed to chemotherapy. DFS and OS exhibited no significant differences between these two salvage therapies. After a change to second chemotherapy, 58.8% (10/17) patients had PD or SD. With the exception of tumor size, pretreatment T stage, and histology type, no other significant differences were noted between PD and pCR patients. Our results demonstrated that PD patients were associated with a significantly worse prognosis. Based on these results, we suggest to give the addition of trastuzumab to HER-2 positive patients instead of changing the chemotherapy regimen and proceeding to surgery instead of further chemotherapy once patients have PD during NACT. Given that some similar characteristics exist between PD and pCR patients, more studies to identify novel molecular markers to predict disease response to NACT should be performed.

Case Report: Metastatic breast cancer to the gallbladder

Cholecystitis is one of the leading causes of emergency surgical interventions; the occurrence of metastases to the gallbladder is rare and has only been reported in the literature exceptionally. Metastatic breast cancer to the gallbladder is even less frequent; in fact, breast cancer usually metastasizes to bone, lung, lymph nodes, liver and brain. We report the case of an 83-year-old female patient with a previous history of breast surgery with axillary dissection in 1997, followed by adjuvant chemotherapy due to invasive ductal carcinoma of the left breast. The patient was admitted at the emergency department for sepsis and an episode of acute kidney failure, anuria and fever. Right-upper quadrant abdominal pain triggered by food intake and abdominal tenderness was also present, placing the diagnostic suspicion of biliary sepsis due to acute cholecystitis. The histological examination of the surgical specimen highlighted the presence of metastasis from an infiltrating ductal breast carcinoma with positive hormone receptors. We also report here the results of a review of the literature looking at articles describing cases of gallbladder metastasis from breast cancer.

Primary signet ring cell carcinoma of the breast: A rare entity with unique biological behavior-A clinical study based on pure signet ring cell carcinoma cohort

BACKGROUND

Primary signet ring cell carcinoma (SRCC) of the breast is a rare entity, and only a few case reports of the pure SRCC cases could be found in English literatures. We summarized the clinicopathological characteristics of a relatively large cohort of pure breast SRCCs for the first time.

METHODS

We reviewed the medical records of 23 cases of pure breast SRCC with a median follow-up time of 70 months.

RESULTS

Three patients had bilateral primary breast cancer (BC) and two of them had bilateral pure SRCCs. 30 % of patients had the malignant tumor family history including two bilateral BC patients. Malignant calcification was observed in 35.3 % of mammography images. Multifocal lesions were microscopically found in 26.1 % of cases. 63.6 % of the cases had lymph node metastasis, 45.5 % were classified as Stage III, 69.6 % had high value of Ki-67 index, and 34.8 % were triple negative subtype. 19.0 % of patients had local recurrence, and 52.6 % had distant metastasis. Four in five patients with positive tumor family history and follow-up data had relapse of SRCC. The 5-year overall survival rate was 73.7 %, the 5-year relapse-free survival rate was 54.3 %, and the 5-year breast cancer specific survival rate was 78.3 %.

CONCLUSION

Pure SRCC of the breast showed an aggressive behavior. Neoadjuvant chemotherapy could be considered, breast-conserving surgery should be prudently chosen, and axillary lymph node dissection may be necessary. The high rate of positive tumor family histories and high bilateral incidence, which showed an adverse effect on prognosis, indicate the unique genetic burden of SRCC.

Breast Cancer Metastasis Masquerading as Primary Colon and Gastric Cancer: A Case Report

<strong>BACKGROUND</strong> Breast cancer is the most common malignancy in women worldwide. Despite treatment, recurrence and metastasis are common. Lobular breast cancer most commonly metastasizes to the lungs, liver, lymph nodes, and sites in the brain. Metastasis to the gastrointestinal tract is rare, with few cases reported to date. <strong>CASE REPORT</strong> This report describes a patient with late colon and gastric metastases from lobular breast cancer mimicking primary colon and gastric cancers. <strong>CONCLUSIONS</strong> Immunohistochemical methods can help differentiate metastatic breast disease to the gastrointestinal tract from primary gastrointestinal malignancy.

Lobular breast cancer: patterns of intraabdominal metastatic spread on imaging and prognostic significance

OBJECTIVE

To retrospectively review the frequency, patterns and intra-abdominal sites of metastatic invasive lobular breast cancer, and to correlate the findings with overall survival.

MATERIALS AND METHODS

From a pathology database search revealing 327 patients with metastatic lobular breast cancer at our institution from January 2004 through August 2014, imaging was available in 116 patients (age range, 31-87 years, mean age, 55). Simple descriptive statistics were performed to record and tabulate the abdominal metastatic spread. Prognostic significance of abdominal metastases and individual abdominal metastatic sites was studied using the Log-rank test and construction of Kaplan-Meier curves.

RESULTS

The most frequent sites of intra-abdominal metastatic invasive lobular breast cancer were peritoneum (55 patients, 47%), followed by liver (37 patients, 32%), bowel (34 patients, 29%), ovary (33 patients, 28%), retroperitoneum (16 patients, 14%), ureter (16 patients, 14%), and lymph nodes (15 patients, 13%). Bowel obstruction was noted in 15 patients (13%) and hydronephrosis in 25 patients (22%). The median abdominal metastasis-free survival was 76 months (interquartile range: 17-191). The overall survival (OS) was 86 months (interquartile range: 49-188). Patients with abdominal metastases had shorter OS. Patients with hepatic metastases had shorter overall survival than those patients without hepatic metastases (p = 0.02, Log-Rank test).

CONCLUSION

Invasive lobular breast cancer has a predilection for metastasizing to both typical (liver) and atypical intra-abdominal sites (peritoneum, GI tract, and adnexa). Presence of intra-abdominal disease and hepatic metastases in patients with ILC negatively affects overall survival.

Breast Metastasis from Gastric Signet Ring Cell Carcinoma, Mimicking Inflammatory Carcinoma. A Case Report

We report a case of breast metastasis of signet ring cell gastric cancer clinically presented as a primary inflammatory carcinoma. Metastases to the breast are uncommon; review of the literature demonstrated only 300 cases. The clinical and radiographic features of the metastatic lesion were unlike those reported in the literature. Although a primary signet ring cell breast carcinoma was described, the pathologic patterns of the breast lesion, here reported, lead us to conclude this was a metastasis and not another primary tumor.

Adenomyoepithelioma of the Breast. A Case Report

Adenomyoepithelioma is a proliferative disorder of both epithelial and myoepithelial cells. This lesion may be found in salivary glands, skin appendages and, very rarely, in the mammary gland. Adenomyoepithelioma was first described in 1970 and very few cases have so far been reviewed in the literature. This paper reports the clinical, histological and immunohistochemical characteristics of an adenomyoepithelioma in a 24 year old woman; to our knowledge this is the first published case in such a young patient. The clinical feature suggested a fibroadenoma. A more complete study of the excised tumor tissue by immunohistochemical and ultrastructural analysis proved that the correct diagnosis was adenomyoepithelioma. Whether adenomyoepithelioma is a benign or a low-grade malignant lesion is still controversial and, therefore, the therapeutic approach is not well defined.

Duodenal Obstruction from Isolated Breast Cancer Metastasis a Case Report

Metastatic involvement of the upper gastrointestinal tract from breast cancer has been reported in autopsy series as occurring in more than 15% of patients, usually associated with extensive systemic spread; clinical manifestations from such metastases have been described in less than 1% of cases. Lobular infiltrating carcinoma seems to have a different metastatic pattern than the ductal type, with an apparent predilection for the gastrointestinal tract. Metastatic presentation as an isolated intestinal obstruction without other signs of metastatic spread is extremely rare. We present a case of isolated duodenal metastasis from breast cancer, associated with intestinal obstruction, as the first sign of metastatic spread.

Metastatic colonic and gastric polyps from breast cancer resembling hyperplastic polyps

Breast cancer metastasis to the gastrointestinal tract is relatively rare and is generally found when patients complain of symptoms such as gastrointestinal obstruction. Herein, we report a case with metastatic colonic and gastric lesions from breast cancer, with the formation of mucosal polyps which resembled typical hyperplastic polyps.

A 47-year-old woman underwent curable surgery for breast cancer and received standard systemic treatments. Her primary tumor was composed of a mix of invasive lobular and ductal carcinomas. During adjuvant endocrine therapy, she developed multiple colonic metastases, identified by colonoscopy performed as part of a general health check-up. She had no symptoms. Small elevated sessile polyps in the transverse colon and rectum showed histological features of signet-ring cell type adenocarcinoma, similar to the invasive lobular component of the primary breast cancer. During treatments for recurrent disease, she also developed multiple gastric metastases, with the same endoscopic and pathological features as the colonic lesions. Her treatment regimen was switched to oral chemotherapy, and she has since maintained stable disease for nearly 3 years. Multiple bone metastases eventually developed, and she was again switched to another systemic treatment but, to date, has remained free of symptoms.

We emphasize that the endoscopic findings of the metastatic lesions in the colon and stomach in this case highly resembled hyperplastic polyps. Since biopsy is not always performed for hyperplastic polyps in the gastrointestinal tract, we believe that this case report may encourage endoscopists to offer biopsies to the patient who has a history of breast cancer.

Colonic metastasis from breast carcinoma: a case report

BACKGROUND

Colonic metastasis from breast carcinoma is very rare. Here, we report a case of colonic metastasis from breast carcinoma.

CASE PRESENTATION

The patient was a 51-year-old woman. She had upper abdominal pain, vomiting, and diarrhea, repeatedly. We performed abdominal contrast-enhanced computed tomography (CT) to investigate these symptoms. The CT scan revealed a tumor in the ascending colon with contrast enhancement and showed an expanded small intestine. For further investigation of this tumor, we performed whole positron emission tomography-computed tomography (PET-CT). The PET-CT scan revealed fluorodeoxyglucose uptake in the ascending colon, mesentery, left breast, and left axillary region. Analysis of biopsy samples obtained during colonoscopy revealed signet ring cell-like carcinoma. Moreover, biopsy of the breast tumor revealed invasive lobular carcinoma. Therefore, the preoperative diagnosis was colonic metastasis from breast carcinoma. Open ileocecal resection was performed. The final diagnosis was multiple metastatic breast carcinomas, and the TNM classification was T2N1M1 Stage IV.

CONCLUSIONS

We presented a rare case of colonic metastasis from breast carcinoma. PET-CT may be useful in the diagnosis of metastatic breast cancer. When analysis of biopsy samples obtained during colonoscopy reveals signet ring cell-like carcinoma, the possibility of breast cancer as the primary tumor should be considered.

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.

Poorer Prognosis of Primary Signet-Ring Cell Carcinoma of the Breast Compared with Mucinous Carcinoma

Primary signet-ring cell carcinoma (PSRCC) of the breast is a rare entity and classified under mucin producing tumors in the WHO classification. However, little is known about the clinicopathological characteristics and clinical outcomes of PSRCC as opposed to mucinous carcinoma. Eleven patients with PSRCC in our center from 1995 to 2010 were evaluated in this study, as compared to 50 cases of mucinous breast cancer (MBC) during the same period. The clinicopathologic features of PSRCC compared to MBC were assessed. Furthermore, overall survival (OS) and disease-free survival (DFS) were calculated at 5 years of follow up. Patients with PSRCC showed more frequent lymphatic metastasis, higher Ki67 labeling index and more advanced stage disease than that of MBC (P = 0.018, p = 0.023, P = 0.000, respectively), although there was no difference in age, tumor size, and ER, PR expression between PSRCC and MBC. In addition, PSRCC was associated with simultaneous vimentin upregulation and E-cadherin downregulation. The 5-year OS of PSRCC (54.5%) was significantly lower than that of MBC (88%) (P = 0.004). Similarly, the DFS of PSRCC was poorer than that of MBC significantly (5-year DFS: 27.3% vs. 80%, P = 0.000).

Morphological features and mucin expression profile of breast carcinomas with signet-ring cell differentiation

Signet-ring cells are relatively common in breast cancers but are frequently overlooked. Although previously defined as a subtype of mucin producing carcinomas, breast carcinomas with signet-ring cell (SRC) differentiation nowadays are not considered a distinct entity. The objective of the present study was to characterize the morphological features and mucin expression profile of breast carcinomas with SRC differentiation. All breast carcinomas diagnosed at Centro Hospitalar S. Joao between 1996 and 2006 in which the pathology report mentioned the presence of SRCs (n=11) and four mucinous carcinomas were included in the study. The frequency of SRCs and immunohistochemistry expression of MUC1/MUC2/MUC5AC/MUC6 were evaluated. We confirmed that SRC differentiation can occur in different histological types, including ductal, lobular, mucinous and metaplastic carcinomas. The proportion of SRCs was highly variable (range: 8-70%). Tumors encompassed SRCs of intracytoplasmic lumina and goblet-cell type. A higher percentage of SRCs was associated with lymphovascular invasion (p=0.047). All tumors expressed cytoplasmic and membranous MUC1. Secretory mucins were more frequent in mucinous carcinomas and in carcinomas with extensive SRC differentiation. We conclude that besides the usefulness of mucin immunodetection for the differential diagnosis of carcinomas with SRC differentiation of breast origin, it is important to report SRC differentiation regardless of histological type because of its intrinsic prognostic value.

Characterization of Spontaneous Mammary Tumors in Domestic Djungarian Hamsters (Phodopus sungorus)

Mammary tumors that spontaneously occurred in domestic Djungarian hamsters ( Phodopus sungorus) were histologically examined. Forty-five mammary tumors included 14 adenomas, 18 adenocarcinomas, 1 lipid-rich carcinoma, 2 adenoacanthomas, 2 malignant adenomyoepitheliomas, 1 benign mixed tumor, and 7 “balloon cell” carcinosarcomas. The latter 4 types were newly recognized neoplasms in Djungarian hamsters. The relatively high incidence of spontaneous mammary carcinosarcomas in domestic Djungarian hamsters is intriguing. Carcinosarcomas exhibited anomalous histological features made up of a mixture of glandular cells, polygonal cells (including “balloon cells”), and sarcomatous spindle cells in varying proportions. Transitional features from glandular cells to polygonal cells and subsequently to sarcomatous spindle cells were observed. Using immunohistochemistry, we observed that glandular cells exhibited an epithelial phenotype (cytokeratin(+)/vimentin(–)), spindle cells exhibited a mesenchymal phenotype (cytokeratin(–)/vimentin(+)), and polygonal cells exhibited an intermediate phenotype (cytokeratin(+)/vimentin(+)). Reduction or loss of β-catenin expression and gain of S100A4 expression were observed in polygonal and spindle cells. The polygonal cell population included a varying number of characteristic cells that were expanded by large intracytoplasmic vacuoles. Electron microscopy revealed that these “balloon cells” had large cytoplasmic lumens lined by microvilli. These observations suggest that epithelial-mesenchymal transition may account for the pathogenesis of mammary carcinosarcomas in Djungarian hamsters.

Breast metastasis of gastric signet-ring cell carcinoma: a case report and literature review

Background

Cases of primary gastric adenocarcinoma with metastasis to the breast are extremely rare. Till now, only 38 cases have been reported in PubMed since 1908.

Case presentation

We herein reported a race case of gastric adenocarcinoma with metastasis to the right breast. Breast biopsy showed invasive signet-ring cell breast carcinoma in the right breast. She was given a TEC regimen (docetaxel 75 mg/m², epirubicin 75 mg/m², and cyclophosphamide 600 mg/m² every 3 weeks) for one cycle but showed no objective response. Upper gastrointestinal endoscopy demonstrated an ulcerative mass in the gastric body. Biopsy demonstrated low-grade gastric adenocarcinoma with signet-ring features. In immunohistochemistry, mammary malignant cells were positive for cytokeratin 7, cytokeratin 20, villin, and ErbB2/HER2, but negative for gross cystic disease fluid protein-15, estrogen receptor, and progesterone receptor. The diagnosis of metastatic poorly differentiated signet-ring cell adenocarcinoma of the right breast identical to gastric primary was confirmed finally.

Conclusions

Gastric cancer with metastasis to the breast can be diagnosed by clinical history, histological findings, and immunohistochemical markers.

Pure primary signet ring cell carcinoma breast: A rare cytological diagnosis

Signet ring cell carcinoma (SRCC) of the breast is a rare tumor and it is classified by World Health Organization in 2003 classification under ‘mucin producing carcinomas’. Pure form of SRCC breast is an extremely rare entity and very few cases have been reported in literature so far. We present a case of pure primary SRCC of the breast in a 70-year-old female, which was diagnosed on fine needle aspiration cytology. Cytological features generally show cellular smears with tumor cells showing eccentrically placed large, irregular nuclei showing indentations at places with cytoplasmic vacuoles. This case is being presented in view of its characteristic cytological features and its rarity.

Retroperitoneal fibrosis as a result of signet ring cell gastric cancer: a case-based review

BACKGROUND

Retroperitoneal fibrosis is a rare and obvious condition in the abdominopelvic cavity. Signet ring cell carcinoma of the stomach with gross appearance of linitis plastica is another rare association.

CASE PRESENTATION

We present a rare case of a 49-year-old woman presenting with persistent nausea and vomiting for 20 days. Three months ago, she was admitted with severe flank pain and was referred to the urology service. She was placed with stents for strictures in both ureters. She underwent endoscopy for heartburn, melena, dyspepsia, and weight loss (7 kg/5 month), which revealed congestion of the mucosa of the fundus and body with fine linear erosion and decreased distensibility of the stomach suggesting linitis plastica. A biopsy indicated full-thickness infiltration by signet ring cell gastric cancer. A CT scan showed evidence of retroperitoneal fibrosis with large lymph nodes around the aorta.

CONCLUSION

This paper shows that the gastric linitis plastica can present with many deceptive clinical presentations, raising the risk of postponed diagnosis.

Estrogen switches pure mucinous breast cancer to invasive lobular carcinoma with mucinous features

Mucinous breast cancer (MBC) is mainly a disease of postmenopausal women. Pure MBC is rare and augurs a good prognosis. In contrast, MBC mixed with other histological subtypes of invasive disease loses the more favorable prognosis. Because of the relative rarity of pure MBC, little is known about its cell and tumor biology and relationship to invasive disease of other subtypes. We have now developed a human breast cancer cell line called BCK4, in which we can control the behavior of MBC. BCK4 cells were derived from a patient whose poorly differentiated primary tumor was treated with chemotherapy, radiation and tamoxifen. Malignant cells from a recurrent pleural effusion were xenografted in mammary glands of a nude mouse. Cells from the solid tumor xenograft were propagated in culture to generate the BCK4 cell line. Multiple marker and chromosome analyses demonstrate that BCK4 cells are human, near diploid and luminal, expressing functional estrogen, androgen, and progesterone receptors. When xenografted back into immunocompromised cycling mice, BCK4 cells grow into small pure MBC. However, if mice are supplemented with continuous estradiol, tumors switch to invasive lobular carcinoma (ILC) with mucinous features (mixed MBC), and growth is markedly accelerated. Tamoxifen prevents the expansion of this more invasive component. The unexpected ability of estrogens to convert pure MBC into mixed MBC with ILC may explain the rarity of the pure disease in premenopausal women. These studies show that MBC can be derived from lobular precursors and that BCK4 cells are new, unique models to study the phenotypic plasticity, hormonal regulation, optimal therapeutic interventions, and metastatic patterns of MBC.

Frequency and etiology of unexplained bilateral hydronephrosis in patients with breast cancer: results of a longitudinal CT study

We retrospectively reviewed the records of 153 patients with breast cancer undergoing serial abdominal computed tomography (CT). During a median follow-up of 40 months, 2 (1.4%) of 153 patients developed bilateral hydronephrosis in the absence of radiologically visible obstructing pathology. Surgery confirmed malignant infiltration of the ureters by metastatic lobular carcinoma in both patients, suggesting that new unexplained bilateral hydronephrosis on serial CT in patients with breast cancer is likely to reflect infiltrative retroperitoneal involvement of the ureters by metastatic lobular carcinoma.

Signet-ring cell carcinoma of the breast with uterine metastasis treated with extensive cytoreductive surgery: a case report and brief review of the literature

Primary signet-ring cell carcinoma (SRCC) of the breast is an uncommon variant, accounting for 2-4.5% of all primary breast cancers. Secondary SRCC of the endometrium is very rare and usually originates from the breast or gastrointestinal tract. A 54-year-old, postmenopausal woman with a past history of breast cancer four years previously was admitted with abnormal uterine bleeding. An endometrial biopsy revealed undifferentiated adenocarcinoma with signet-ring cells. The patient underwent laparotomy and cytoreductive surgery was performed. Pathological analysis and immunohistochemical tests demonstrated a uterine (endomyometrial) metastasis of breast SRCC. Omentum, peritoneal surfaces and retroperitoneal lymph nodes also included tumoral tissue with signet-ring cell morphology. The patient received adjuvant systemic chemotherapy with adriamycin, cyclophosphamide and paclitaxel. This case report discusses the patient's clinical characteristics and the role of cytoreductive surgery on patient survival in SRCC of the breast metastasizing to the uterus.

Primary pure signet cell carcinoma of the breast: a case report and review of the literature

Signet ring cell carcinoma (SRCC) of the breast is a rare tumor that is classified into mucinous carcinoma and other tumors with abundant mucin as an independent subset and entity under the 2003 World Health Organization (WHO) classification of tumors of the breast. Pure form SRCC is very rare. To date, only a few cases have been reported in the literature. A case of primary SRCC of the breast in a 48-year-old woman is presented in this report. Histologically, the majority of the neoplastic cells are characterized by large intracytoplasmic mucin, compressing the nuclei toward one pole of the cell. The patient underwent both mastectomy and axillary lymph node excision. Adjuvant chemotherapy and chest wall irradiation were performed, and the case was discharged and followed up in remission for 20 months. The primary breast tumor was confirmed by clinical, morphological, and immunohistochemical studies. Characteristic features and differential diagnosis of this tumor were discussed in the light of pertinent literature.

Metastatic Signet-Ring Cell Gastric Carcinoma Masquerading as Breast Primary

Metastasis to the breast from an extra-mammary primary is a rare phenomenon; metastasis from gastric carcinoma to the breast is extremely so. We report a case who initially presented as mucin-secreting and signet-ring cell tumor of the ovary, and after an interval of 8 months with breast and chest wall metastatic nodules. The covert gastric primary eluded the oncologists at both presentations.

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.

Pleomorphic lobular carcinoma of the breast: molecular pathology and clinical impact

Pleomorphic lobular carcinoma of the breast is a recently described morphological variant of classic invasive lobular carcinoma with an aggressive behavior. Morphologically, pleomorphic lobular carcinoma elicits a similar pattern of infiltrative growth as invasive lobular carcinoma, yet neoplastic cells have marked nuclear atypia and pleomorphism. Pleomorphic lobular carcinoma and the in situ counterpart, pleomorphic lobular carcinoma in situ, are frequently hormone receptor (estrogen-, progesterone- and androgen-receptor)-positive and E-cadherin and β-catenin-negative, attaining to their lobular nature. Tumors can also be positive for HER2, p53, ki67 and GCDFP-15 and harbor frequent chromosomal alterations involving gains on 1q and 16p, losses on 11q and 16q, and genomic amplifications in the region of 8q24, 11q13, 12q13, 17q12 and 20q13. Recent gene-expression profiling classified pleomorphic lobular carcinoma as ‘molecular apocrine’ tumors reflecting the frequent apocrine differentiation of the tumors. In support for the aggressive biological features described for pleomorphic lobular carcinoma, accumulating clinical data demonstrate that it has an aggressive clinical course. It is now important to define the most appropriate management strategy for patients diagnosed with pleomorphic lobular carcinoma.

Absence of E-cadherin expression distinguishes noncohesive from cohesive pancreatic cancer

PURPOSE

The role of E-cadherin in carcinogenesis is of great interest, but few studies have examined its relevance to pancreatic carcinoma.

EXPERIMENTAL DESIGN

We evaluated E-cadherin protein expression by immunohistochemistry in pancreatobiliary cancers having a noncohesive histologic phenotype (21 undifferentiated adenocarcinomas and 7 signet ring carcinomas), comparing the results with pancreatic cancers having a cohesive phenotype (25 moderately differentiated and 14 poorly differentiated adenocarcinomas).

RESULTS

Twenty of 21 undifferentiated cancers had complete absence of E-cadherin expression, as did two signet ring carcinomas. In contrast, cohesive cancers (n = 39) had E-cadherin labeling at the plasma membrane (P < 0.001). Subsets of cancers were also evaluated for beta-catenin expression. All of the cohesive lesions (n = 28) showed a membranous beta-catenin expression pattern, whereas noncohesive foci (n = 7) were characterized by either cytoplasmic labeling or complete absence of beta-catenin protein expression, suggestive of a deficient zonula adherens in noncohesive cancers. E-cadherin promoter hypermethylation was observed in an undifferentiated pancreatic cancer cell line, MiaPaCa-2, whereas two pancreatic cancer cell lines derived from differentiated lesions lacked any evidence of E-cadherin promoter methylation. No pattern of E-cadherin promoter methylation could be determined in three primary cancers having mixed histologic patterns (contained both cohesive and noncohesive foci). No somatic mutations in E-cadherin were identified in noncohesive pancreatic cancers having inactivated E-cadherin.

CONCLUSIONS

Noncohesive pancreatic cancers were characterized by the loss of E-cadherin protein expression. Promoter hypermethylation is a possible mechanism of E-cadherin gene silencing in a subset of these cancers.

Breast signet-ring cell lobular carcinoma presenting with duodenal obstruction and acute pancreatitis

We report here an extremely rare case of breast signet-ring cell carcinoma (SRCC) initially manifesting as duodenal metastasis and acute pancreatitis. A 62-year-old female presented with duodenal obstruction and swollen head of the pancreas, and the diagnosis of acute pancreatitis was initially made. Upper gastrointestinal endoscopy revealed duodenal stenosis with erosive mucosa, with signet-ring cells infiltrating the submucosal layer, suggesting duodenal metastasis of SRCC. Despite absence of a palpable mass in both breasts, computed tomography revealed diffuse enhancement of the left breast in addition to left axillary lymphadenopathy. Histological examination of mammary needle biopsy samples revealed SRCC with a non-invasive lobular carcinoma component. Primary breast SRCC with duodenal metastasis was therefore diagnosed. The patient underwent palliative surgery twice for intestinal obstruction due to peritoneal dissemination. She has remained alive without bowel obstruction for 18 months while being treated with cytotoxic chemotherapies.

Expression of aberrant mucins in lobular carcinoma with histiocytoid feature of the breast

The clinicopathological profiles of histiocytoid carcinoma of the breast have not been well examined because of their rarity and heterogenous groups of ductal and lobular origin. A large foamy or granular cytoplasm of histiocytoid carcinoma was characterized by abundant mucin, but the properties of mucin in histiocytoid carcinoma have also not been well investigated. We selected eight cases of histiocytoid features of invasive lobular carcinoma (HLC) and compared with 14 age- and tumor size-matched cases of classical invasive lobular carcinoma (CLC). Mucin profiles were significantly different between the two groups: a fair number of HLC cases were immunopositive for MUC2 and MUC5AC (75 and 50%, respectively); in contrast, almost all CLC cases showed both as negative. Both groups were immunopositive for MUC1 and negative for MUC4 and MUC6. The prognosis of HLC was significantly worse than CLC; HLC showed shorter disease-free time than CLC (p=0.0262). In particular, HLC with MUC2 and MUC5AC expressions showed significantly shorter disease-free time and survival time than lobular carcinoma without the expressions of MUC2 and MUC5AC (p=0.0055 and p=0.0060, respectively). Therefore, the expression of 'non-mammary mucins', such as MUC2 and MUC5AC in HLC, is characteristic and indicates the more malignant transformation of tumor cells and poorer prognosis.

Pleomorphic lobular carcinoma in situ of the breast composed almost entirely of signet ring cells

Some examples of lobular carcinoma in situ (LCIS) may be composed in part of signet ring cells. Such proliferations have been considered examples of pleomorphic LCIS based on pathological features of the more conventional component. However, the occurrence of LCIS composed entirely of signet ring cells is extraordinarily rare. This report describes an example of an in situ proliferation that was composed almost entirely (>95%) of signet ring cells, which was unassociated with an invasive carcinoma and which showed comedo-type necrosis. There was only focal lobulocentric distention by lesional cells, as is typical of classic LCIS. However, discrete, ductal-type cross-sectional profiles showed a purely intraepithelial proliferation of remarkably discohesive signet ring cells. The signet ring cells had intermediate-grade nuclear atypia, no significant mitotic activity and were positive for mucicarmine and PAS stains (the latter with and without diastase predigestion). The cells displayed marked immunoreactivity for high-molecular-weight keratin (stained by 34beta E12 antibody), MUC1, gross cystic disease fluid protein-15, cytokeratin 7 and were negative for cytokeratin 20, E-cadherin, progesterone receptor and HER2/neu. It is concluded that this is an example of a purely signet ring variant of pleomorphic LCIS.

The management of lobular carcinoma in situ (LCIS). Is LCIS the same as ductal carcinoma in situ (DCIS)?

Lobular carcinoma in situ was first described over 60 years ago. Despite the long history, it continues to pose significant difficulties in screening, diagnosis, management and treatment. This is partly due its multi-focal and bilateral presentation, an incomplete understanding of its biology and natural history and perpetuation of misconceptions gathered over the last decades. In this review, the working group on behalf of EUSOMA has attempted to summarise the current thinking and management of this interesting lesion.

A case of breast cancer metastatic to the tail of the pancreas

Breast cancer metastasis to pancreas is rarely seen. There have been only 6 cases described in the literature. We present the seventh case of a 54-year-old woman with breast cancer that metastasized to the tail of the pancreas 4 years and 4 months after radical mastectomy. Although the serum levels of CA15-3 and TPA had gradually increased without symptoms, it was difficult to establish the diagnosis before contrast-enhanced abdominal CT scan was performed. Immunohistochemical staining using E-cadherin was positive, proving that the breast cancer was ductal rather than lobular in origin. CA15-3 immunohistochemically stained positive in the resected pancreas lesion. Positive monoclonal staining by GCDFP-15 (gross cystic disease fluid protein-15) in the pancreas tumor also confirmed it breast cancer origin. Investigation of chemokine/chemokine receptors may clarify a new mechanism of metastasis to the pancreas from breast cancer.

Gastric signet-ring adenocarcinoma presenting with breast metastasis

Breast metastases from gastric cancer are extremely rare. A case report of a 37-year-old female with breast inflammatory invasion and ascites is described. Breast biopsy revealed carcinomatous invasion of the lymphatics from adenocarcinoma cells with signet-ring features. Estrogen (ER) and progesterone receptors (PR) and c-erb-B2 were negative. Upper gastrointestinal endoscopy revealed a prepyloric ulcerative mass. Histopathologic examination of the lesion showed infiltration from a high-grade adenocarcinoma, identical with that of the breast. Immunostaining was positive for cytokeratins CK-7 and CK-20 and CEA and negative for ER and PR. Ascitic fluid cytology was positive for adenocarcinoma cells. Mammography was not diagnostic. Abdominal CT scanning revealed large ovarian masses suggestive of metastases (Krukenberg’s tumor). A cisplatin-based regimen was given but no objective response was observed. The patient died six months after initial diagnosis. A review of the literature is performed.

Clinical and pathological features of glycogen-rich clear cell carcinoma of the breast

BACKGROUND

Twenty cases of invasive ductal carcinoma of the breast with a pure or partial glycogen-rich clear cell carcinoma(GRCC)component are reported. GRCC of the breast is composed almost entirely of polygonal cells with clear cytoplasm. These contain large amounts of partly water-soluble glycogen.

METHODS

The cases were analyzed using various parameters, including age at presentation, tumor size, tumor grade, axillary lymph node and Her2/neu status.

RESULTS

Between 1990 and 2004, 723 patients with primary breast carcinomas were treated and clinicopathologic analysis was performed. 20 cases were identified as GRCC among the 723 cases. The patients' age at presentation ranged from 33 to 68 years (mean, 52 years). Tumor size ranged from 1 to 6.5 cm (mean, 2.6 cm); 35% (7 of 20) of cases that underwent axillary dissection had positive lymph nodes. Among 15 of 20 cases who were followed for 1-72 months, 5 cases died from their breast carcinoma within 5 years following the diagnosis.

CONCLUSION

Our series included more small size carcinomas than did previous series. Lymph node status does not appear to be markedly different from that of the usual invasive ductal carcinomas. Her2/neu expression was similar to that found in common breast carcinomas.

Glycogen-rich clear cell mammary malignant myoepithelioma

Primary clear cell tumors of the breast are uncommon and often present a diagnostic challenge. We describe an extremely rare case of glycogen-rich clear cell malignant myoepithelioma in a 43-year-old woman. Histologically, this tumor is composed of clear cells with abundant cytoplasmic glycogen particles. Immunohistochemically, these tumor cells show co-expression of vimentin, smooth muscle actin, epithelial membrane antigen, S-100 protein, and cytokeratin as evidence of myoepithelial cell tumor. The pathological staging of the patient is IIB (pT3N0M0) and the nuclear grading is 2. The patient demonstrated no evidence of recurrence or metastasis over a period of 42 months. We suggest that glycogen-rich clear cell malignant myoepithelioma be included in the histological differential diagnosis of clear cell tumors of the breast.

Wide metastatic spreading in infiltrating lobular carcinoma of the breast

The aim of this study was to determine whether the metastatic potential of breast cancer could be related to phenotypic characteristics of the tumour. Therefore, we compared the metastatic patterns of invasive lobular (ILC) and ductal (IDC) carcinomas. In ILC, we also analysed this pattern according to the histological subtype of the primary and the E-cadherin (EC) expression level. Metastatic ILC cases (n=96) were retrospectively analysed and classified into classical, alveolar, solid, tubulo-lobular, signet ring cells or pleomorphic subtypes. Anatomical distribution of metastases was detailed for every patient and compared with that registered for IDC (n=2749). Immunostaining of EC (HECD1 antibody) was performed in 82 cases. Histologically, 78 of the 96 cases (81%) corresponded to classical ILC. The pleomorphic subtype was observed in 14 cases (15%), a rate that was higher than that expected. Others corresponded to alveolar (2 cases), signet ring cell (1 case) and solid (1 case) subtypes. EC was undetectable in 72/82 cases (88%). The rate of multiple metastases was higher in ILC (25.0%) than in IDC (15.8%) (P=0.016). Metastases were found more frequently in ILC than in IDC in the bone (P=0.02) and/or in various other sites (peritoneum, ovary, digestive tract, skin em leader ) (P<0.001). In ILC, no significant link was found between the localisation(s) of metastases, the histological subtype and the EC status in the primary. In conclusion, in breast carcinomas, the frequency of multiple metastasis was found to be higher in ILC than IDC. This fact may be related to the phenotypic trait of discohesive small cells which characterises ILC. EC loss, observed in most cases of ILC, may result in alterations in cell-cell adhesion and a preferential growth at metastatic sites. A high rate of pleomorphic tumours was observed in the group of metastatic ILC, but the pattern of metastatic site(s) was not related to the histological subtype of the primary.

Primary and metastatic lobular carcinoma of the breast

Invasive lobular carcinoma of the breast is the second most common type of primary breast cancer, accounting for 8-14% of cases, but is often difficult to diagnose early. It typically shows a diffuse pattern of infiltration within the breast, resulting in a variety of often subtle radiological appearances. A similar infiltrative pattern is seen in its metastatic form, with involvement of the gastrointestinal tract, peritoneum, retroperitoneum, bone marrow, meninges and uterus occurring more frequently than with the more common infiltrating ductal carcinoma of the breast. This pictorial essay illustrates the spectrum of radiological appearances which may be encountered with both primary and secondary lobular carcinoma.

Pleomorphic lobular carcinoma: morphology, immunohistochemistry, and molecular analysis

Infiltrating pleomorphic lobular carcinoma (PLC) is an aggressive variant of infiltrating lobular carcinoma. Recently, in situ changes identical to PLC (PLCIS) have been described. The role of prognostic markers and their correlation with therapeutics, clinical outcome, and genetic changes is not well established in PLC. The authors examined 38 cases of this entity to understand better this tumor's biology. Immunohistochemical (IHC) analysis was performed in 21 specimens for estrogen and progesterone steroid receptors, p53, Her 2 (p185), and GCDFP-15. Genomic deoxyribonucleic acid was obtained from microdissected tumor as well as normal control cells, and loss of heterozygosity was investigated at the ESR (16q24), p53 (TP53 17p), Her 2 (17q 11-12), and BRCA 1 (17q12-25) loci. In this series, the average patient age was 57.5 years (age range, 24-92 years). Twenty-seven women were postmenopausal. Tumor size ranged from 1.2 to 25 cm. Six patients were a pathologic stage I; 19, stage II; 12, stage III; and one, stage IV. Histologically, multifocal nodular aggregates of discohesive pleomorphic tumor cells were seen interspersed in dense and fibrotic breast parenchyma. Twenty-nine percent of the specimens demonstrated associated signet ring cells. The remainder had dishesive, globoid, plasmacytoid cells with high-grade nuclear features. PLCIS was identified in 17 of 38 patients (45%), and lobular carcinoma in situ (LCIS) was noted in 8 patients (21%). IHC analysis showed estrogen immunoreactivity in 81%, progesterone in 67%, GCDFP-15 in 71%, and Her 2 in 81% (2+ to 3+ membranous staining) of specimens. Antibodies to p53 stained the tumor cell nuclei in 48% of the tumors. Loss of heterozygosity was identified in 52% of the specimens at the p53 locus, 18% at the ESR locus, 19% to 24% at the Her 2 loci, and 27% to 32% at the BRCA 1 locus. Follow-up was available in 19 patients and ranged from 12 months to 15 years (mean, 73 months). Seven patients had no evidence of disease at last examination (range, 1-15 years), three patients were alive with disease (range, 2-14 years), and nine patients were dead of disease (range, 2 months-9 years). Six patients had subsequent diagnoses of tumor in the contralateral breast. Analysis shows that PLC tends to appear in older postmenopausal women who present with locally advanced disease. PLCIS was found to be associated with PLC 45% of the time. The aggressive clinical course of patients with PLC is supported by tumor immunoreactivity with unfavorable markers Her 2 and p53. Overexpression of Her 2 in PLC may be therapeutically relevant, enabling the use of novel chemotherapeutic drugs like Herceptin. Interestingly, tumors that were Her 2 immunoreactive also maintained estrogen hormone immunoreactivity.