Quantitative assessment of PD-L1 as an analyte in immunohistochemistry diagnostic assays using a standardized cell line tissue microarray.

Programmed death 1 ligand 1 (PD-L1) Immunohistochemistry (IHC) is the key FDA-approved predictive marker to identify responders to anti-PD1 axis drugs. Multiple PD-L1 IHC assays with various antibodies and cut points have been used in clinical trials across tumor types. Comparative performance characteristics of these assays have been extensively studied qualitatively but not quantitatively. Here we evaluate the use of a standardized PD-L1 Index tissue microarray (TMA) to objectively determine agreement between antibody assays for PD-L1 applying quantitative digital image analysis. Using a specially constructed Index TMA containing a panel of ten isogenic cell lines in triplicate, we tested identical but independently grown batches of isogenic cells to prove Index TMAs can be produced in large quantities and hence serve as a standardization tool. Then the Index TMAs were evaluated using quantitative immunofluorescence (QIF) to validate the TMA itself and also to compare antibodies including E1L3N, SP142 and SP263. Next, an inter-laboratory and inter-assay comparison of 5 PD-L1 chromogenic IHC assays (US Food and Drug Administration (FDA) approved and lab developed test (LDT)) were performed at 12 sites around the USA. As previously reported, the SP142 FDA assay failed to detect low levels of PD-L1 in cell lines distinguished by the other four assays. The assays for 22C3 FDA, 28-8-FDA, SP263 FDA, and E1L3N LDT were highly similar across sites and all laboratories showed a high consistency over time for all assays using this Index TMA. In conclusion, we were able to objectively quantify PD-L1 expression on a standardized Index TMA using digital image analysis and we confirmed previous subjective assessments of these assays, but now in a multi-institutional setting. We envision commercial use of this Index TMA or similar smaller version as a useful standardization mechanism to compare results between institutions and to identify abnormalities while running routine clinical samples.

Human breast cancer biopsies induce eosinophil recruitment and enhance adjacent cancer cell proliferation.

Chronic inflammation is known to facilitate cancer progression and metastasis. Less is known about the effect of acute inflammation within the tumor microenvironment, resulting from standard invasive procedures. Recent studies in mouse models have shown that the acute inflammatory response triggered by a biopsy in mammary cancer increases the frequency of distal metastases. Although tumor biopsies are part of the standard clinical practice in breast cancer diagnosis, no studies have reported their effect on inflammatory response. The objective of this study is to (1) determine whether core needle biopsies in breast cancer patients trigger an inflammatory response, (2) characterize the type of inflammatory response present, and (3) evaluate the potential effect of any acute inflammatory response on residual tumor cells. The biopsy wound site was identified in the primary tumor resection tissue samples from breast cancer patients. The inflammatory response in areas adjacent (i.e., immediately around previous biopsy site) and distant to the wound biopsy was investigated by histology and immunohistochemistry analysis. Proliferation of tumor cells was also assayed. We demonstrate that diagnostic core needle biopsies trigger a selective recruitment of inflammatory cells at the site of the biopsy, and they persist for extended periods of time. While macrophages were part of the inflammatory response, an unexpected accumulation of eosinophils at the edge of the biopsy wound was also identified. Importantly, we show that biopsy causes an increase in the proliferation rate of tumor cells located in the area adjacent to the biopsy wound. Diagnostic core needle biopsies in breast cancer patients do induce a unique acute inflammatory response within the tumor microenvironment and have an effect on the surrounding tumor cells. Therefore, biopsy-induced inflammation could have an impact on residual tumor cell progression and/or metastasis in human breast cancer. These findings may carry relevance in the clinical management of breast cancer.

Using American Type Culture Collection Cell Lines to Evaluate Interlaboratory Variables for Estrogen Receptor and Human Epidermal Growth Factor Receptor 2 Immunostaining.

CONTEXT.­: Most laboratories currently use patient tissues for validating immunohistochemical stains. OBJECTIVE.­: To explore advantages of using cell lines with known antigenicity as a validation method. DESIGN.­: Five American Type Culture Collection (ATCC) cell lines with known negative, low positive, and moderate to strong estrogen receptor (ER) expression as well as negative, equivocal, and positive human epidermal growth factor receptor 2 (HER2) expression were cultured and made into cell blocks. One block from each cell line was fixed in formalin and another in ethanol before cell block preparation. Two sets of paired unstained slides from each block were sent to 10 different laboratories for HER2 and ER staining to be stained on runs from different days according to each laboratory's defined protocol. RESULTS.­: The 10 study participants evaluated 40 slides in a blinded fashion. For ER expression, all 80 interpretations for the ER strong and moderate positive cell lines had the target ER-positive result, and 74 of 80 ER-negative cell lines (92.5%) had agreement with the intended negative result. The ER low positive cell line showed varied but positive expression among all observers. The HER2 (3+)-positive cell lines yielded a target interpretation of 3+ in 65 of 80 interpretations (81.2%). For the HER2-negative cell line 69 of 78 interpretations (88.5%) were consistent with the target response (0 or 1+). No significant variation was observed between the ethanol- and non-ethanol-exposed cell lines, or between runs by the same laboratory. Variation from target results clustered within laboratories. CONCLUSIONS.­: This study indicates that variability between laboratories can be identified by using cell lines for quantitative or semiquantitative immunohistochemistry when using cultured cell lines of known antigenicity. These cell lines could potentially play a role in aiding anatomic pathology laboratories in validating immunohistochemistry tests for formalin- and ethanol-fixed tissues.

Validation of p16 immunocytochemical staining on alcohol-fixed aspirate smears: A single-institutional study with review of the literature.

BACKGROUND: Determining human papillomavirus (HPV) status in oropharyngeal squamous cell carcinoma can have a significant impact on treatment and clinical outcomes. Because fine-needle aspiration (FNA) is typically an initial diagnostic modality in a patient workup for primary or suspected metastatic disease, immunostaining for p16 on FNA material is a promising option to determine HPV tumor status, possibly avoiding biopsies or excisions. In this study, the authors investigated the possibility of using alcohol-fixed smears as a reliable alternative for reporting p16 status. METHODS: Twenty HPV-associated tumors and 20 non-HPV-associated tumors were identified using the gold-standard histologic cutoff for positivity of ≥70% strong nuclear and cytoplasmic staining. Matched FNA specimens were identified for comparison staining, and a positive p16 result was rendered on a single aspirate smear using the same cutoff of ≥70%. RESULTS: On alcohol-fixed cytology smears, 16 of 20 (80%) HPV-associated tumors showed positive p16 staining in ≥70% tumor cells. Four cases showed lower level (30%-60%) nuclear and cytoplasmic staining. Nineteen of 20 (95%) non-HPV-associated tumors showed no or minimal p16 staining (0%-10%), and 1 case had a p16-equivocal cytology result. CONCLUSIONS: The authors performed immunocytochemical validation for p16 using alcohol-fixed smears and observed promising results, offering this technique as a potential alternative to formalin-fixed tissue in the appropriate clinical context. By using a positive staining cutoff of ≥70%, this technique offers 80% sensitivity and 95% specificity for detecting HPV-associated tumors. Although it was not performed in the current study, HPV-specific testing on available formalin-fixed, paraffin-embedded tissue should be considered in cases with equivocal or negative p16 staining.

Follicular and Hürthle cell lesions of the thyroid: can inconclusive results be minimized?

OBJECTIVE: To assess the cytologic criteria for distinguishing neoplastic from nonneoplastic follicular cell and Hürthle cell thyroid lesions. STUDY DESIGN: Ten previously described and commonly used cytologic criteria were evaluated and graded on a 0-4 scale in a consecutive series of thyroid fine needle aspirations (FNAs) reported as follicular or Hürthle cell neoplasms or lesions. Scoring was compared to subsequent surgical outcome. RESULTS: A total of 93 (57fo llicular cell and 36 Hühle cell) cases was analyzed. No individual cytologic feature was helpful in distinguishing benign neoplarms from malignancy in either category (p > 0.05), but 4 or more coexistent cytologic features in combination were identified in 50.0% of follicular neoplasms, 13.6% of Hürthle cell neoplasms and none of the nonneoplastic lesions. An unexpected number (13 of 93, 14.0%) of unrecognized papillary carcinomas, some of follicular subtype, was encountered. CONCLUSION: In this series, the indeterminate thyroid FNA category could have been reduced by diagnosis of samples with 4 or more of the studied criteria as definite follicular (50% of cases) or Hürthle cell (13.6% of cases) neoplasms and by more astute recognition of papillary carcinomas (14.0% of cases), which blend into this category, often as a result of less-than-optimal sampling or preservation.

Investigation of HNF-1B as a diagnostic biomarker for pancreatic ductal adenocarcinoma.

BACKGROUND: Diagnosing pancreatic ductal adenocarcinoma (PDAC) in the setting of metastasis with an unknown primary remains very challenging due to the lack of specific biomarkers. HNF-1B has been characterized as an important transcription factor for pancreatic development and was reported as a biomarker for clear cell subtype of PDAC. METHODS: To investigate the diagnostic role of HNF-1B for PDAC, we used tissue microarray (TMA) and immunohistochemistry (IHC) to characterize HNF-1B expression in a large cohort of carcinomas, including 127 primary PDACs, 47 biliary adenocarcinomas, 17 metastatic PDACs, and 231 non-pancreaticobiliary carcinomas. RESULTS: HNF-1B was expressed in 107 of 127 (84.3%) of PDACs, 13 of 15 (86.7%) of cholangiocarcinomas, 13 of 18 (72%) of ampullary carcinomas, and 13 of 14 (92.9%) of gallbladder adenocarcinomas. Notably, HNF-1B was expressed in 16 of 17 (94.1%) of metastatic PDACs. Among the non-pancreaticobiliary cancers, HNF-1B was expressed in ~ 77% clear cell carcinomas of the kidney and ovarian clear cell carcinomas. Gastroesophageal, lung, and prostate adenocarcinomas occasionally expressed HNF-1B in up to 37% cases. HNF-1B was completely negative in hepatocellular, colorectal, breast, and lung squamous cell carcinomas. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of HNF-1B for primary pancreaticobiliary carcinoma is 84, 68, 66, 85, and 75%, respectively. HNF-1B expression was not significantly associated with overall survival in patients with PDAC, but tumor size ≥2 cm and high tumor grade were significantly associated with worse overall survival in multivariate analyses. CONCLUSIONS: HNF-1B may be used in surgical pathology to aid the diagnosis of metastatic pancreatic and biliary carcinoma with a panel of other markers to exclude lung, kidney, prostate, and Müllerian origins.

NKX2.2, PDX-1 and CDX-2 as potential biomarkers to differentiate well-differentiated neuroendocrine tumors.

BACKGROUND: Well-differentiated neuroendocrine tumors (NET) most frequently arise from the gastrointestinal tract (GI), pancreas, and lung. Patients often present as metastasis with an unknown primary, and the clinical management and outcome depend on multiple factors, including the accurate diagnosis with the tumor primary site. Determining the site of the NET with unknown primary remains challenging. Many biomarkers have been investigated in primary NETs and metastatic NETs, with heterogeneous sensitivity and specificity observed. METHODS: We used high-throughput tissue microarray (TMA) and immunohistochemistry (IHC) with antibodies against a panel of transcriptional factors including NKX2.2, PDX-1, PTF1A, and CDX-2 on archived formalin-fixed paraffin-embedded NETs, and investigated the protein expression pattern of these transcription factors in 109 primary GI (N = 81), pancreatic (N = 17), and lung (N = 11) NETs. RESULTS: Differential expression pattern of these markers was observed. In the GI and pancreatic NETs (N = 98), NKX2.2, PDX-1, and CDX-2 were immunoreactive in 82 (84%), 14 (14%), and 52 (52%) cases, respectively. PDX-1 was expressed mainly in the small intestinal and appendiceal NETs, occasionally in the pancreatic NETs, and not in the colorectal NETs. All three biomarkers including NKX2.2, PDX-1, and CDX-2 were completely negative in lung NETs. PTF1A was expressed in all normal and neuroendocrine tumor cells. CONCLUSIONS: Our findings suggest that NKX2.2 was a sensitive and specific biomarker for the GI and pancreatic neuroendocrine tumors. We proposed that a panel of immunostains including NKX2.2, PDX-1, and CDX-2 may show diagnostic utility for the most common NETs.

Transition to Subspecialty Sign-Out at an Academic Institution and Its Advantages.

Many pathology departments are introducing subspecialty sign-out in surgical pathology. In 2014, the University of Vermont Medical Center transitioned from general sign-out to partial subspecialty sign-out to include gastrointestinal and breast/cervix subspecialty benches; other specimens remained on general benches. Our experiences with the transition are described, including attending pathologist, trainee, support staff, and clinician satisfaction. A survey was e-mailed to all University of Vermont Medical Center anatomic pathology attendings, pathology trainees, pathologist assistants and grossing technicians, and clinicians who send surgical pathology specimens, immediately before and 1 year after transitioning to partial subspecialty sign-out. Quality assurance metrics were obtained for the 18 months prior to and following the transition. Gastrointestinal and breast/cervix attendings were more satisfied with partial subspecialty sign-out compared to those on the general benches. Overall, trainees were more satisfied with general sign-out because of the rotation schedule but preferred partial subspecialty sign-out due to improved teaching and more focused learning while on subspecialty benches. Clinicians remained very satisfied with our department and our reports; no differences were observed. Turnaround time was unchanged. After switching to partial subspecialty sign-out, there were significantly fewer discrepancies following multidisciplinary conference review for gastrointestinal and breast/cervix cases but remained the same for general cases. Fewer formal internal consults were performed after transitioning to partial subspecialty sign-out across all areas, but more notable for gastrointestinal and breast/cervix cases. Our data show improved quality assurance metrics and trainee education in a subspecialty sign-out setting compared to general sign-out setting.

Recommendations for Pathologic Evaluation of Reduction Mammoplasty Specimens: A Prospective Study With Systematic Tissue Sampling.

CONTEXT: - Breast reduction mammaplasty (RMP) for symptomatic macromastia or correction of asymmetry is performed in more than 100 000 patients per year in the United States. The reported incidence of significant pathologic findings (SPF), that is, carcinoma and atypical hyperplasia, ranges from 0.06% to 12.8%. No standard pathology assessment for RMP exists. OBJECTIVES: - To propose standard sampling for microscopic evaluation in RMP specimens, to evaluate the incidence of occult carcinoma and atypical hyperplasia, and to identify clinical risk factors for SPF in patients undergoing RMP. DESIGN: - All RMP specimens from 2006 to 2013 at a single institution were prospectively examined. After baseline gross and microscopic evaluations, each specimen was subjected to systematic additional sampling. The incidence of SPF was tabulated, and variables such as age, specimen weight, previous history of SPF, and results of preoperative mammogram were examined. Clinical follow-up review was also subsequently undertaken. RESULTS: - A total of 595 patients were evaluated. Significant pathologic findings were present in 9.8% (58 of 595) of patients. No cancer was identified in patients younger than 40 years; the rates of carcinoma were 2.4% (14 of 595) in all patients, 3.6% (14 of 392) in patients aged 40 years or older, and 4.3% (10 of 233) in patients aged 50 years or older. No carcinoma or atypical hyperplasia was identified on preoperative mammogram. Increased sampling was associated with a significantly greater frequency of SPF only in patients aged 40 years or older. CONCLUSIONS: - In patients younger than 35 years, gross-only evaluation is sufficient. However, increased sampling may be necessary in patients older than 40 years.

Comparison of Estrogen and Progesterone Receptor Antibody Reagents Using Proficiency Testing Data.

CONTEXT: - Immunohistochemical analysis of estrogen receptor (ER) and progesterone receptor (PgR) expression in breast cancer is the current standard of care and directly determines therapy. In 2010 the American Society of Clinical Oncology and the College of American Pathologists (ASCO/CAP) published guidelines for ER and PgR predictive testing, encompassing preanalytic, analytic, postanalytic factors; antibody validation; and proficiency testing. OBJECTIVE: - To compare the performance of different antibody reagents for ER and PgR immunohistochemical analysis by using CAP proficiency testing data. DESIGN: - The CAP PM2 survey uses tissue microarrays of ten 2-mm cores per slide. We analyzed survey data from 80 ER and 80 PgR cores by antibody clone from more than 1200 laboratories. RESULTS: - Laboratories used the ER antibodies SP1 (72%), 6F11 (17%), 1D5 (3%), and the PgR antibodies 1E2 (61%), 16 (12%), PgR-636 (13%), PgR-1294 (8%) in 2015. While 63 of 80 ER cores (79%) were scored similarly using each of the 3 antibodies, there were significant differences for others, with SP1 yielding more positive interpretations. Four cores were scored as ER negative by more than half of the laboratories using 1D5 or 6F11, while SP1 produced positive results in more than 70% of laboratories using that antibody. Despite the greater variety of PgR antibody reagents and greater PgR tumor heterogeneity, 61 of 80 cores (76%) were scored similarly across the 4 PgR antibodies. CONCLUSIONS: - Accurate ER and PgR testing in breast cancer is crucial for appropriate treatment. The CAP proficiency testing data demonstrate differences in staining results by ER clone, with SP1 yielding more positive results.

Papillary carcinoma of the breast in a male patient with a treated prostatic carcinoma diagnosed by fine-needle aspiration biopsy: a case report and review of the literature.

Papillary carcinoma of the male breast is very rare. In this case report, we describe the cytologic, histologic, immunohistochemical, and radiological findings of a papillary carcinoma of male breast. A 67-yr-old man, who had a previous history of prostatic adenocarcinoma, presented with a retroareolar painless mass. There was no known history of breast cancer in his family. A fine-needle aspiration biopsy (FNAB) was performed. Cytological examination revealed a cellular aspirate with three-dimensional papillary clusters. A diagnosis of papillary lesion favoring papillary carcinoma was rendered. Immunohistochemical staining of the cell-block of the FNAB revealed the presence of mammaglobin, and the absence of prostatic specific antigen. The patient underwent lumpectomy, which showed a moderately differentiated infiltrating papillary carcinoma with adjacent areas of ductal carcinoma in situ. FNAB is a useful technique in identifying male breast carcinoma. In conjunction with ancillary studies, this procedure can effectively differentiate between a primary versus metastatic lesion.

Increased utilization, verification, and clinical implications of immunocytochemistry: Experience in a northern New England hospital.

BACKGROUND: We report our experience in utilization, verification, and clinical implications of antibodies for use in diagnostic immunocytochemistry (ICC). METHODS: A computer search identified cytology cases utilizing ICC and corresponding surgical pathology material. Alcohol-fixed liquid based cytology (LBC) specimens were generated from surgical pathology bench specimens. ICC on LBC and immunohistochemistry on formalin fixed paraffin embedded tissue (FFPE) were performed in parallel for 71 commonly used antibodies. Cytology and corresponding surgical pathology reports were reviewed for all cases in which antibodies failed verification studies but had been used in the four years prior to implementation of our verification process. RESULTS: From 2007 to 2011, the number of cytology cases in which ICC was performed increased from 98 (or 5% of all non-Pap test/nonurine cytology cases in our laboratory) to 306 (or 15%). Verification studies revealed calretinin, CD5, c-kit/CD117, inhibin, napsin A, OCT 3/4, and PAX-5 to be nonreliable in LBC despite consistent immunoreactivity in concurrent IHC on surgical specimens. No antibodies were found to be immunoreactive on LBC but nonreactive on FFPE. No adverse clinical outcomes resulted from the use of nonverified antibodies. CONCLUSIONS: Utilization of ICC at our institution has increased dramatically in recent years. Our verification process confirmed reliability in the majority of antibodies, but did identify several inconsistent antibodies. Although, in our series, no adverse clinical outcomes resulted from preverification use of these inconsistent antibodies, we encourage other institutions to confirm reliability of antibodies prior to use for diagnostic ICC.

IgG4-Related Neuromyopathy Associated With Recurrent Pleural Effusion.

OBJECTIVE: Immunoglobulin G4-related disease (IgG4-RD) is an increasingly recognized idiopathic systemic disorder associated with elevated serum IgG4 level and tissue infiltration by IgG4-positive plasma cells. Multiple neurological manifestations, including peripheral neuropathy, have been described in IgG4-RD. Our objective is to discuss a case report and review of the literature, which would expand the spectrum of IgG4-RD. METHODS: We describe the clinical features and biopsy findings in a patient with IgG4-RD who presented with features suggestive of neuromyopathy in the setting of recurrent pleural effusion and weight loss. RESULTS: Electrodiagnostic findings were suggestive of an irritable myopathy and polyradiculoneuropathy with primary demyelination and secondary axonal degeneration. Pleural biopsy and laboratory studies confirmed the diagnosis. Improvement was sustained with steroid therapy. CONCLUSIONS: We describe the first case, to our knowledge, of IgG4-related neuromyopathy associated with recurrent pleural effusion. Our case expands the clinical spectrum of IgG4-RD. Neurologists should be aware of this treatable disorder and in the appropriate clinical context consider it in the differential diagnosis of neuromyopathy.

Metastatic melanoma presenting as an isolated breast tumor: a study of 20 cases with emphasis on several primary mimickers.

CONTEXT: The mammary gland can be a site of metastasis in patients with malignant melanoma, which is easily recognized microscopically if clinical information is available. Nonetheless, metastatic melanoma presenting as an isolated mammary tumor can be more challenging to diagnose because it can simulate a primary breast carcinoma clinically and morphologically. OBJECTIVE: To review metastatic melanoma to the breast, presenting as primary breast carcinomas clinically and morphologically. DESIGN: The authors report 20 cases of metastatic melanoma clinically presenting as breast tumors. Cases with widespread metastatic presentation were excluded. RESULTS: Epithelioid and spindle cell tumors predominated, suggesting mammary ductal, papillary, or sarcomatoid carcinoma. Most cases (16 of 20) were submitted for consultation or second opinion owing to their unusual presentation in the breast, or to perform predictive/prognostic immunohistochemical assays. Seven cases had a remarkable phenotypic spectrum expanding the differential diagnosis to large cell lymphoma, leiomyosarcoma, medullary carcinoma, malignant schwannoma, and liposarcoma. Tumor cells were negative for cytokeratin stains and positive for S100 protein, HMB-45, and Melan-A. Negative staining was also observed for epithelial membrane antigen, CD45, desmin, estrogen and progesterone receptors, and human epidermal growth factor receptor 2. CONCLUSIONS: Metastatic melanoma may simulate a broad spectrum of primary breast malignancies. Although the application of a simple panel of antibodies assists in rendering the correct interpretation, lesions presenting as isolated breast tumors may introduce a significant diagnostic difficulty, especially when there is inadequate patient history and/or limited biopsy material. Further challenges are introduced by the extraordinary phenotypic plasticity of metastatic melanoma. Awareness of this pattern variance is essential to avoid inappropriate treatment, especially in cases simulating a "triple negative," poorly differentiated carcinoma of the breast.

Adult testicular granulosa cell tumor: a review of the literature for clinicopathologic predictors of malignancy.

Adult testicular granulosa cell tumors are rare sex cord-stromal tumors of which only 28 have been previously reported. As compared with their ovarian counterparts, these tumors may follow a more aggressive course because the proportion of malignant cases is higher. To date, there are no clinical or pathologic features that definitively predict malignancy. We reviewed all prior case reports for features that may predict their malignant potential. Tumor size greater than 5.0 cm is the only feature statistically associated with malignancy. Mitotic count, tumor necrosis, patient age, and the presence of gynecomastia do not, at present, predict benign versus malignant behavior.

Immunohistochemical analysis of ER, PR, Her2 and CK5/6 in infiltrative breast carcinomas in Indian patients.

AIM: Breast cancer is biologically a heterogeneous disease. Patients with the same diagnostic profile have markedly different clinical outcomes. Gene expression studies identified distinct breast cancer subtypes that differ in prognosis. Aim is to identify the immunohistochemical subtypes of breast carcinoma and correlate the results with pathological features associated with adverse prognosis in our study population. METHOD: We included 107 consecutive cases of invasive breast carcinoma and sub classified using immunohistochemical staining for ER, PR, Her2, and CK5/6 into the following subtypes: luminal A, luminal B, basal-like, Her2(+) and unclassified. Associations between tumor subtypes and tumor characteristics were examined. RESULTS: The proportion of each subtype in our patient population was: luminal A 37.4%, luminal B 11.1%, Her2(+) 29% and basal-like 7.5%. The following variables were significantly associated with IHC breast cancer subtypes: patient age (p<0.05), overall histopathology grade (p<0.001), nuclear grade (p<0.005) and mitotic index (p<0.001). Her2(+) and basal like subtypes were associated with poor differentiation (p<0.01), higher nuclear grade (p<0.05) and high mitotic index (p<0.05). CONCLUSIONS: Our data show a higher proportion of patients in the study population undergo total mastectomy and harbor poorly differentiated, node positive tumors than reported. There was also a relatively high percentage of the Her2(+) subtype (29%).

Carcinoma and atypical hyperplasia in reduction mammaplasty: increased sampling leads to increased detection. A prospective study.

BACKGROUND: Reduction mammaplasty for symptomatic macromastia or correction of asymmetry is performed more than 100,000 times per year in the United States. The reported incidence of occult breast cancer in reduction mammaplasty ranges from 0.06 to 4.6 percent. No standard pathology assessment for reduction mammaplasty exists. The authors evaluated the incidence of occult carcinoma and atypical hyperplasia in reduction mammaplasty specimens and identified clinical risk factors. Systematic sampling of additional tissue sections was instituted to evaluate the hypothesis that increased sampling would identify more significant pathologic findings. METHODS: All reduction mammaplasty specimens over a 20-month period at a single institution were prospectively examined. All specimens had baseline gross and microscopic evaluations, and then each was subjected to systematic additional sampling. The incidence of significant pathologic findings (carcinoma and atypical hyperplasia) was tabulated. Variables such as age and preoperative mammogram were examined. RESULTS: A total of 202 cases were evaluated. Significant pathologic findings (carcinoma and atypical hyperplasia) were present in 12.4 percent. The rate of carcinoma was 4 percent in all patients (6.2 percent in patients >or=40 years and 7.9 percent in patients >or=50 years). CONCLUSIONS: A significantly higher rate (12.4 percent) of significant pathologic findings was identified in this prospective study compared with published literature. None of the lesions was identified on preoperative mammogram. Age was significantly associated with significant pathologic findings. Increased sampling was associated with significant pathologic findings only in patients 40 years or older, indicating the need for thorough sampling of reduction mammaplasty specimens in patients older than 40.

The detection of isolated tumor cells in bone marrow comparing bright-field immunocytochemistry and multicolor immunofluorescence.

BACKGROUND: The detection of isolated tumor cells in bone marrow by immunocytochemistry (ICC) has been reported to predict progression of early-stage breast cancer. The most common staining procedure uses bright-field ICC with cytokeratin (CK) antibodies to label isolated tumor cells. However, this method can result in false-positive staining events. We used multicolor immunofluorescence (IF) to develop a more specific assay for detecting isolated tumor cells in marrow samples from breast cancer patients. METHODS: We compared ICC and IF side by side for detection of cancer cells and false-positive staining events on bone marrow aspirates from breast cancer patients, bone marrow from healthy donors, and healthy donor blood spiked with cancer cells. The primary target for isolated tumor cell detection was CK for both methods. IF used an additional set of antibodies to label hematopoietic cells (HCs). RESULTS: The detection rate of CK+ events in breast cancer patient bone marrow aspirates was 18 (58%) of 31 for ICC and 21 (68%) of 31 for IF. However, with IF, 17 of 21 CK+ cases were stained with HC markers and thus were identified as false-positive events. A surprisingly high CK+ event rate was observed in healthy donor blood and marrow. In all healthy donor samples, CK+ events were readily identified as HCs by IF. Detection sensitivity of spiked cancer cells in donor blood was similar for both methods. CONCLUSIONS: There is a high frequency of CK+ events in blood and marrow, and it is important to note that this is observed both in patients with and those without cancer. IF with multiple HC markers allows straightforward discrimination between CK+ cells of hematopoietic and nonhematopoietic origin.