Reductions in tumor RNA integrity associated with clinical response to epirubicin/docetaxel chemotherapy in breast cancer patients

Abstract #6068

Background: Optimal doses and dosing intervals for neoadjuvant anthracycline/taxane chemotherapy are poorly studied. Moreover, biomarkers for measuring response to such combination regimens are unknown. This study investigated these issues in sequential phase I/II cohorts of women with locally advanced or inflammatory breast cancer treated with epirubicin and docetaxel with pegfilgrastim support at 3- or 2-weekly intervals in association with the NCIC-CTG MA.22 clinical trial.
 Methods: Accrual has been completed for the 3-weekly regimen (maximum tolerated dose: epirubicin 105 mg/m2, taxotere 75 mg/m2), and continues for the phase II portion of the 2-weekly regimen. Six core biopsies were obtained from 50 patients pre-, mid-, and post-treatment. Immunohistochemical staining was performed to determine baseline levels of ER, PR, HER2 and Topo II expressed as % positive stain. Tumour RNA integrity (RIN) and tumor extent were measured pre-, mid- and post-treatment by capillary electrophoresis and light microscopy after haematoxylin/eosin staining, respectively. Associations between maximum and average RIN at the three time points and tumour extent, clinical response, pathologic complete response, or baseline levels of ER, PR, HER2 and Topo II were assessed using Spearman correlation coefficients after data transformation to improve symmetry and stabilize variances. The association between both RIN and tumour extent, and baseline drug dose was assessed using a 1-way ANOVA.
 Results: Low mid-treatment maximum RIN was associated with high drug dose level (p=0.05) and eventual pathologic complete response (p=0.01). Post-treatment, low maximum and average RIN were found to be associated with low tumor extent (p=0.004 and p=0.01, respectively). As well, low average RIN was significantly associated with clinical complete response post-treatment (p=0.01). As expected, post-treatment low tumor extent was significantly associated with pathologic complete response (p=0.01). High pre-treatment Topo II levels were also significantly associated with high RIN (p = 0.03). No association was observed between RIN and HER2, ER or PR.
 Discussion: The association of RIN with tumour extent, pathologic complete response, clinical response, a known risk factor (Topo II), and drug dose suggests that the RIN may represent an important new biomarker for measuring response to anthracycline/taxane combinations (and possible other chemotherapy regimens) in breast cancer patients.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6068.

Defining a test for HER-2/neu evaluation in breast cancer in the diagnostic setting

In breast cancer amplification of the HER-2/neu oncogene and over-expression of the protein product is associated with poor prognosis, predicts response to some chemotherapeutic regimens and is the target for Herceptin treatment. To date there are several methods to assess the amplification/over-expression of HER-2/neu with each having advantages and disadvantages. We have studied amplification and over-expression of HER-2/neu in 250 consecutive cases of breast cancer (220 invasive and 30 in situ carcinomas) presenting to the Department of Pathology at Women's College Campus of Sunnybrook and Women's College Health Sciences Center. Thirty percent of the invasive carcinomas were node positive. HER-2/neu protein over-expression was assessed by immunohistochemistry (IH) using antibody CB11 and amplification of the gene by differential PCR. The percentage of tumor cells showing CB11 staining was determined and the most significant cut off point for positivity was > or =10% moderate or strong complete membranous staining. The gene was considered amplified if the density score of the product was > or =2. There was 94% concordance between the two methods (P value.0001). Both methods were positive in 16% of cases and negative in 78% of cases. Discrepant cases were examined by FISH which confirmed the IH results in 9/11 invasive carcinomas. These results show that there is excellent concordance between IH and PCR. However, immunohistochemistry is easier to perform and cheaper than PCR and could be used in routine assessment of HER-2/neu in breast cancer patients.

Loss of androgen receptor associated protein 70 (ARA70) expression in a subset of HER2-positive breast cancers

Co-transfection studies indicate that HER2 (erbB-2) overexpression results in the phosphorylation and enhanced transcriptional activity of the androgen receptor (AR). This amplification of AR action is further enhanced by the expression of ARA70, a putative co-activator with a predilection for the AR. Because androgens inhibit the growth of breast cancer cells whereas HER2 overexpression stimulates the growth of these cells, it seems possible that loss of expression of AR or ARA70 in some HER2 overexpressing tumors might confer a growth advantage to these cells. We examined ARA70 and AR expression in 20 HER2-positive (overexpressing) and 21 HER2-negative cases of breast invasive ductal carcinoma (IDC) to determine the relationship between loss of ARA70 and/or AR with HER2 overexpression. Strong ARA70 immunostaining was observed in all normal and breast epithelial cells in fibrocystic change and in in situ carcinoma present in the patient samples. Of the 41 cases of IDC, focal or complete loss of ARA70 protein expression was observed in 46% of the cases, with 60% of HER2-positive versus 33% of HER2-negative cases showing loss. Loss of AR expression was observed in 60% of HER2-positive versus 43% of HER2-negative cases. Remarkably, only 20% of HER2-positive tumors expressed both AR and ARA70, while 43% of HER2-negative tumors expressed both of these elements of the AR signaling pathway. This trend is consistent with a possible clinical relevance of the potential crosstalk between the HER2 and AR signaling pathways. Western blot analysis for ARA70 expression performed on frozen breast biopsies of normal or malignant breast tissue from four patients revealed a 70 kDa immunoreactive band in all four normal tissue samples, with an additional 35 kDa band in two of the breast cancer samples and in human breast cancer MCF-7 cells. This may reflect aberrant splicing in some breast cancers, leading to the emergence of the 35 kDa isoform.

Tenascin differentiates dermatofibroma from dermatofibrosarcoma protuberans: comparison with CD34 and factor XIIIa

Differentiation of dermatofibroma (DF) from dermatofibrosarcoma protuberans (DFSP) can be difficult. CD34 and Factor XIIIa have been used to differentiate DF from DFSP. However, there is overlap and lack of specificity of their expression. Tenascin is an extracellular matrix glycoprotein that is involved in embryogenesis, carcinogenesis, and wound healing. The aim of the study was to assess the role of tenascin in DF and DFSP and compare the results with those obtained with CD34 and Factor XIIIa. Immunohistochemical staining was performed on 20 cases each of DFSP and DF, using antibodies to tenascin, CD34 and Factor XIIIa, and the streptavidin biotin technique. Positivity for all 3 antibodies was assessed within the tumors. Tenascin expression was also assessed at the dermal-epidermal junction. Strong tenascin positivity was noted at the dermal-epidermal junction overlying the lesion in 20 of 20 cases of DF (100%) and was negative over the lesion in 20 of 20 cases DFSP (100%). Tenascin was noted within the lesion of 80% of both DF and DFSP (16/20 cases). CD34 was strongly expressed in 16 of 20 (80%) DFSP and 5 of 20 (25%) DF, whereas Factor XIIIa was strongly expressed in 19 of 20 (95%) DF and 3 of 15 (15%) DFSP. Although CD34 was expressed in 80% DFSP and Factor XIIIa in 95% of DF, there was overlap in their expression in the 2 types of tumors. The increased expression of tenascin at the dermal-epidermal junction overlying the lesion in DF but not in DFSP, differentiated these 2 tumors. In contrast, tenascin expression within the lesion did not differentiate DF from DFSP.

Factors associated with local breast cancer recurrence after lumpectomy alone: postmenopausal patients

BACKGROUND

We have been following a cohort of patients who underwent a lumpectomy without receiving adjuvant radiotherapy or adjuvant systemic therapy. We now report the experience of a postmenopausal subgroup.

METHODS

The postmenopausal subgroup included 244 patients accrued between 1977 and 1986 and followed up. The end point was ipsilateral local breast cancer recurrence. The factors studied were the patient's age in years; tumor size (in mm); nodal status (N-, Nx, N+); estrogen and progesterone receptor status (< 10, - 10 fmol/mg protein); presence or absence of lymphovascular/perineural invasion; presence or absence, and type, of DCIS (none, non-comedo, comedo); percentage of DCIS; histological grade (1,2,3); and nuclear grade (1,2,3). Univariate analyses consisted of Kaplan-Meier plots and the Wilcoxon (Peto-Prentice) test statistic; the multivariate analyses were step-wise Cox and log-normal regressions.

RESULTS

The median follow-up of those patients still alive was 9.1 years, and the overall relapse rate was 24% (59/244). The univariate results indicated that the characteristics of smaller tumor size, negative nodes, positive ER status, and no lymphovascular or perineural invasion were associated with significantly (P <.05) lower relapse. From the multivariate analyses, the factors lymphovascular or perineural invasion, age, and amount of DCIS were all significantly associated with local relapse with both Cox and log-normal regressions. Additionally, there was weak evidence of an association between ER (P = .08 in the Cox regression and in the log-normal) and nodal status (P = .09 in the log-normal regression) with local relapse. We also are able to define a low-risk subgroup (N-, age -65, no comedo, ER positive, no emboli) with a crude 10-year local recurrence rate of 9%.

CONCLUSION

With longer follow-up, and for postmenopausal patients, there continues to be support for the theory that local relapse is affected by the factors lymphovascular or perineural invasion, age, amount of DCIS, ER, and nodal status. A low risk subgroup has been identified.

Factors affecting distant disease-free survival for primary invasive breast cancer: use of a log-normal survival model

BACKGROUND

Invasive breast cancer is a frequently diagnosed disease that now comes with an ever expanding array of therapeutic management options. We assessed the effects of 20 prognostic factors in a multivariate context.

METHODS

We accrued clinical data for 156 consecutive patients with stage 1-3 primary invasive breast cancer who were diagnosed in 1989-1990 at the Henrietta Banting Breast Center, and followed to 1995. There is complete follow-up for 91% of patients (median follow-up of 4.9 years). The event of interest was distant recurrence (for distant disease-free survival, DFS). We used Cox and log-normal step-wise regression to assess the multivariate effects of the following factors on DFS: age, tumor size, nodal status, histology, tumor and nuclear grade, lymphovascular and perineural invasion (LVPI), ductal carcinoma-in-situ (DCIS) type, DCIS extent, DCIS at edge of tumor, ER and PgR, ERICA, adjuvant systemic therapy, ki67, S-phase, DNA index, neu oncogene, and pRb.

RESULTS

There was strong evidence against the Cox assumption of proportional hazards for nodal status, and nodal status was not in the Cox step-wise model. With step-wise log-normal regression, a large tumor size (P < .001), positive nodes (P = .002), high nuclear grade (P = .01), presence of LVPI (P = .03), and infiltrating duct carcinoma not otherwise specified (P = .05) were associated with a reduction in DFS.

CONCLUSIONS

For nodal status, there was strong evidence against the Cox assumption of proportional hazards, and it was not included in the Cox model although it was in the log-normal model. Only traditional factors were included in the step-wise models. Thus, this statistical management of prognostic markers in breast cancer appears to be very important.

The effects of nicotine on Parkinson's disease

Post-mortem studies have demonstrated a substantial loss of nicotinic receptors in Parkinson's disease (PD), which may be at least partially responsible for some of the cognitive, motoric, and behavioral deficits seen in this disorder. Epidemiologic studies have suggested that cigarette smoking is a strong negative risk factor for the development of PD. We have previously shown that blockade of central nicotinic receptors produces cognitive impairment in areas of new learning, short-term memory, and psychomotor slowing with increasing dose sensitivity with age and disease. Studies of acute stimulation of nicotinic receptors in Alzheimer's disease with nicotine and the novel agonist ABT-418 in our laboratory and others have shown improvements in several measures of cognitive function. Prior studies of the effects of nicotine in PD have suggested some improvements in clinical symptomatology. We have begun quantitative studies of both acute and chronic nicotine in PD to assess both cognitive and motor effects. Fifteen (15) nondemented subjects (age 66 +/- 5.3; M/F = 11/4) with early to moderate PD (mean Hoehn-Yahr stage = 1.77; MMSE = 28.6) received a dose-ranging study of intravenous nicotine up to 1.25 microg/kg/min, followed by chronic administration of nicotine by transdermal patch with doses ranging up to 14 mg per day for 2 weeks. Testing occurred both during drug administration and up to 2 months after drug cessation to look for prolonged effects. Preliminary analysis shows improvements after acute nicotine in several areas of cognitive performance, particularly measures such as reaction time, central processing speed, and decreased tracking error. Improvements in attention and semantic retrieval were not seen. After chronic nicotine, improvements were seen in several motor measures suggesting improved extrapyramidal functioning. This appeared to be sustained for up to 1 month after drug. The treatment was well tolerated. Nicotinic stimulation may have promise for improving both cognitive and motor aspects of Parkinson's disease.

RT-PCR amplification of CK19 mRNA in the blood of breast cancer patients: correlation with established prognostic parameters

We optimized the assay for detection of cytokeratin 19 (CK19) mRNA by the reverse transcriptase-polymerase chain reaction (RT-PCR) in blood as an index of circulating tumor cells in breast cancer patients. The limit of detection of < 1 MCF7 tumor cells per 10(6) peripheral blood leukocytes (PBL) was achieved in mixing experiments. We did not detect CK19 mRNA in control bloods (0/30) or in the blood of patients with benign breast disease (0/15). In blood samples from 109 patients with invasive breast cancer, CK19 mRNA was detected in 7/23 patients with node-negative disease, in 21/58 with node-positive disease, and in 20/28 with distant metastases. There was a significant association (P < 0.01) of CK19 positivity with distant metastatic versus both node-negative and node-positive disease, but not with any other histopathological parameter examined. In a small number of patients with distant metastases, increased intensity of the CK19 RT-PCR signal was associated with a reduced survival.

Evaluation of HER-2/neu (erbB-2) status in breast cancer: from bench to bedside

Molecular alterations in breast cancer are being incorporated into the development of new treatment strategies. The HER-2/neu oncogene has been extensively investigated as a prognostic factor and recently as a predictor of response to chemotherapy or endocrine therapy. The development of a humanized anti-HER-2 monoclonal antibody (Herceptin) and the encouraging results obtained in the treatment of patients with HER-2 overexpressing metastatic breast cancer with this antibody have resulted in renewed interest in HER-2/neu. This article reviews the current knowledge of HER-2/neu both as a prognostic and a predictive factor. Problems associated with the standardization of the methodology for assessing HER-2/neu status and clinically significant cut-off points are addressed.

Inhibition of norepinephrine-induced cardiac hypertrophy in s100beta transgenic mice

We have recently reported that the Ca2+-binding protein S100beta was induced in rat heart after infarction and forced expression of S100beta in neonatal rat cardiac myocyte cultures inhibited alpha1-adrenergic induction of beta myosin heavy chain (MHC) and skeletal alpha-actin (skACT). We now extend this work by showing that S100beta is induced in hearts of human subjects after myocardial infarction. Furthermore, to determine whether overexpression of S100beta was sufficient to inhibit in vivo hypertrophy, transgenic mice containing multiple copies of the human gene under the control of its own promoter, and CD1 control mice were treated with norepinephrine (NE) (1.5 mg/kg) or vehicle, intraperitoneally twice daily for 15 d. In CD1, NE produced an increase in left ventricular/body weight ratio, ventricular wall thickness, induction of skACT, atrial natriuretic factor, betaMHC, and downregulation of alphaMHC. In transgenic mice, NE induced S100beta transgene mRNA and protein, but provoked neither hypertrophy nor regulated cardiac-specific gene expression. NE induced hypertrophy in cultured CD1 but not S100beta transgenic myocytes, confirming that the effects of S100beta on cardiac mass reflected myocyte-specific responses. These transgenic studies complement in vitro data and support the hypothesis that S100beta acts as an intrinsic negative regulator of the myocardial hypertrophic response.

S100beta inhibits alpha1-adrenergic induction of the hypertrophic phenotype in cardiac myocytes

In an experimental rat model of myocardial infarction, surviving cardiac myocytes undergo hypertrophy in response to trophic effectors. This response involves gene reprogramming manifested by the re-expression of fetal genes, such as the previously reported isoform switch from adult alpha- to embryonic beta-myosin heavy chain. We now report the transient re-expression of a second fetal gene, skeletal alpha-actin in rat myocardium at 7 days post-infarction, and its subsequent down-regulation coincident with the delayed induction of S100beta, a protein normally expressed in brain. In cultured neonatal rat cardiac myocytes, co-transfection with an S100beta-expression vector inhibits a pathway associated with hypertrophy, namely, alpha1-adrenergic induction of beta-myosin heavy chain and skeletal alpha-actin promoters mediated by beta-protein kinase C. The induction of beta-myosin heavy chain by hypoxia was similarly blocked by forced expression of S100beta. Our results suggest that S100beta may be an intrinsic negative regulator of the hypertrophic response of surviving cardiac myocytes post-infarction. Such negative regulators may be important in limiting the adverse consequences of unchecked hypertrophy leading to ventricular remodeling and dysfunction.

An improved statistical approach: can it clarify the role of new prognostic factors for breast cancer?

Recently, there has been a proliferation of new biomarkers, some of which may lead to an improved prognostic index or may influence treatment selection. However, there are methodological and statistical issues that require attention in assessing the role and use of these prognostic factors. Between 1977 and 1986, 1097 primary breast cancer patients were accrued for multidisciplinary research at the Henrietta Banting Breast Centre, Women's College Hospital; follow-up to 1990 is complete for 96% of the patients. Data for these patients are used here to illustrate strategies: (1) for the comparison of results from diverse assessments of biomarkers; (2) for the improved comparability of inter-laboratory results; (3) for the examination of the results from monoclonal or polyclonal antibody assays for possible clinically relevant bimodality; (4) for good statistical resolution of overlapping distributions; (5) that involve the use of quantitative values for prognostic factors whenever possible; and (6) for improved multivariate analyses. Good data handling and analyses may enable more accurate and rapid assessment of new prognostic factors, thereby expediting and improving their clinical application.

Alternative multivariate modelling for time to local recurrence for breast cancer patients receiving a lumpectomy alone

Certain prognostic factors (patient and/or tumour characteristics) may be associated with low (or high) risk for local recurrence. Patients with these characteristics could be candidates for less (or more) adjuvant therapy or a less (or more) aggressive surgical approach. However, the assessment of many factors can be problematic with the standard multivariate technique-a Cox proportional hazards model and step-wise regression. We compared the results obtained when using a Cox model with those from four alternative models (exponential, Weibull, log logistic and log Normal) in step-wise and all subset regressions. Between 1977 and 1986, 293 primary invasive breast cancer patients were treated at the Henrietta Banting Breast Centre with a lumpectomy with or without an axillary dissection, and with no postoperative adjuvant therapy. The variables considered were age, lymph node status, tumour size, estrogen receptor (ER), progesterone receptor (PgR), histologic grade, nuclear grade, carcinoma in situ (CIS), amount of CIS, and presence of tumour emboli. With follow-up to 1991, nodal status was not found to be included in the step-wise Cox model, although it was in the step-wise exponential, Weibull and log Normal models, and in the best all subset models for all model types. The variables tumour emboli, ER, age, CIS and nodal status were consistently included in the best all subset regressions, regardless of model type. In the 1993 follow-up, the variables in the step-wise Cox model were tumour emboli, ER, age, CIS and nodal status. The multivariate consideration of all possible subsets of regression variables led to an earlier indication of the importance of nodal status, while the data strongly supported accelerated failure time models over the Cox model.

Controlling for variability in research on normal aging and neuropsychological populations discourse analysis and applications: studies in adult clinical populations

There has been an increase in research during the past few years on discourse, with particular focus on normal older adults and clinical populations, e.g., aphasic and head-injured patients and patients with Alzheimer's disease. A recent edited book, Discourse Analysis and Applications: Studies in Adult Clinical Populations, reviews some of this work. Research on normal older adults and clinical populations raise a number of methodological problems, in particular, variability. Such issues are not easily resolved as we currently have no standard experimental designs for this type of research. This review seeks to point out some of these methodological issues that researchers face and provides some possible solutions.

Proliferative activity and p53 expression in adenoid cystic carcinoma of the breast

Adenoid cystic carcinoma is a rare type of invasive breast carcinoma that has a good prognosis. We studied a series of four cases of adenoid cystic carcinoma in which we correlated the clinical and pathological features. The pathological features examined included light microscopy; electron microscopy; immunohistochemistry using antibodies to keratin, vimentin, S100 protein, actin, estrogen and progesterone receptors, and proliferation marker MiB-1, and p53 suppressor protein; image cytometric analysis for measurement of DNA ploidy; and molecular analysis using polymerase chain reaction single strand conformation polymorphism to assess point mutation of the p53 gene. All of the cases had a low nuclear grade, were negative for estrogen and progesterone receptors, and were DNA diploid. Three of the cases showed no evidence of metastases and had small primary tumors with low proliferative activity and absence of p53 protein expression. In contrast, one of the cases showed axillary lymph node metastases and in this case the primary tumor was large with a higher proliferative activity and expression of p53 protein, suggesting that these factors might play a role in the biological behavior of adenoid cystic carcinoma.

An investigation of cut-points for primary breast cancer oestrogen and progesterone receptor assays

Oestrogen and progesterone receptor (ER and PgR) assay values are frequently used in medical decision-making for breast cancer patients. We have proposed statistical standardization of receptor assay values to improve inter-laboratory comparability, and now report the use of standardized log units (SLU) to investigate the effects of ER and PgR cut-points on time to first recurrence outside the breast (DFS). Between 1980 and 1986, there were 678 primary breast cancer patients treated at the Henrietta Banting Breast Centre (HBBC). The effects of ER and PgR cut-points were examined with multivariate analyses considering the variables: age, tumour size, nodal status, weight and adjuvant treatment. We considered receptor assay cut-points ranging from - 1.0 to + 1.0 SLU (ER between 7 and 166 fmol/mg protein; PgR between 7 and 181 fmol/mg protein). PgR was included in the multivariate prognostic models more often than ER, although patients had a better prognosis with both larger ER and PgR values. There was no best cut-point for ER or PgR, and there was strong evidence that ER and PgR should be considered as continuous rather than dichotomous (negative, positive) variables. Patient prognosis should also be more comparable with SLU.

MIB-1 proliferative activity is a significant prognostic factor in primary thick cutaneous melanomas

Although the Breslow measurement of tumor thickness of melanoma is the most significant predictor of survival, the biologic behavior of thick lesions remains unpredictable. MIB-1, a monoclonal antibody to a Ki-67 epitope, recognizes all proliferating cells. Unlike Ki-67 antibody, which requires frozen tissue, MIB-1 can be used on formalin-fixed tissue. Proliferation, measured by MIB-1 expression and mitotic index, was assessed as a prognostic factor in a group of patients with clinical stage I thick cutaneous melanoma (tumor thickness 4 mm or greater), for which predicted survival is low. From a melanoma data base, 97 patients with this type of melanoma were identified. Of these, 64 had lesional tissue available for study. The median follow-up time was 3.8 years (range 0.42-13.6 years). The percentage of MIB-1 reactivity was scored as low at less than 10% (n = 33), intermediate at 10% to 20% (n = 17), and high at greater than 20% (n = 14). Melanomas with high MIB-1 reactivity were associated with significantly poorer cause-specific survival compared with tumors with intermediate (p < 0.0001) or low MIB-1 reactivity (p = 0.0025). Multivariate analysis demonstrated that MIB-1 reactivity was a significant independent prognostic factor related to cause-specific survival (p = 0.0002) and was more sensitive than tumor thickness or mitotic index in this select group of high-risk patients. Identification of individuals with stage I thick cutaneous melanoma who are at risk of recurrent disease may improve patient management as new therapeutic modalities become available.

bcl-2 protein expression in melanocytic neoplasms of the skin

Since the discovery of bcl-2 proto-oncogene in follicular lymphomas, the protein product has been detected in a variety of normal tissues including skin, where it is expressed in basal keratinocytes. Recent studies indicate that bcl-2 protein is detected in nonlymphoid malignancies such as neuroblastoma and carcinomas of the lung and prostate. This study investigates the presence of bcl-2 protein in benign and malignant melanocytic neoplasms of the skin. Immunohistochemical analysis of bcl-2 protein expression was performed on 39 nevi and 60 malignant melanomas, including 21 metastases. There was diffuse strong immunopositivity for bcl-2 protein in 100% of nevi and 65% (43/60) of primary and metastatic melanomas. bcl-2 protein was diffusely expressed in 67% (30/39) of primary melanomas and 54% (11/21) of metastases. Although bcl-2 immunoreactivity was observed in all levels of primary cutaneous malignant melanomas, in 43% (9/21) of deep melanomas (Clark level > or = III), and 100% (7/7) of thick tumors (thickness > or = 4.00 mm), there was focal loss of immunoreactivity. Metastatic melanomas showed focal loss of bcl-2 expression in 10% (2/21) of cases and total loss of bcl-2 protein in 39% (8/21). We conclude from our results that bcl-2 protein is expressed by benign and malignant melanocytic tumors of the skin, but there is loss of bcl-2 protein expression with increasing tumor progression.

"Aberrant elastic" in elastofibroma: an immunohistochemical and ultrastructural study

Elastofibroma is a rare lesion characterized by the presence of abundant abnormal elastic fibers with a unique morphology, fibroblastic proliferation, and collagen deposition. Whether the altered morphology of the elastic fibers is a degenerative phenomenon or is due to abnormal elastogenesis is controversial. We studied fetal skin and three cases of elastofibroma by light microscopy and immunohistochemistry using an antibody to lysozyme, and one case of elastofibroma by electron microscopy (EM). Our previous studies have shown that normal elastic fibers in adult skin do not stain for lysozyme whereas abnormal elastic fibers in solar elastosis and pseudoxanthoma elasticum react positively for lysozyme. In the fetal skin and all three cases of elastofibroma the elastic fibers were negative for lysozyme. EM showed the abnormal flowerlike configuration of the elastic fibers, which consisted of a central core of normal or degenerating elastin surrounded by radiating spokes of granular and filamentous material of variable electron densities, suggesting that the structure and organization of the microfibrils is abnormal. The absence of lysozyme in the aberrant elastic did not differentiate whether there was excessive production of fetal or adult elastic. However, the excessive amount of microfibrils seen at the ultrastructural level suggests that there may be excessive fetal elastic production. The elastic fibers were intimately related to the fibroblasts and were often present within their caveolae, suggesting that the abnormal elastic fibers are produced by the fibroblast. Our study suggests that abnormal elastogenesis with subsequent degeneration plays a role in the production of the abnormal elastic fibers in elastofibroma.

Characterization of the mononuclear infiltrate involved in regression of halo nevi

Halo nevi are characterized by progressive degeneration of nevus cells surrounded by a mononuclear cell infiltrate. We studied the morphological features of the nevus cells and the composition of the mononuclear cell infiltrate in 15 cases of halo nevi using immunohistochemical techniques and a battery of antibodies to different subsets of lymphocytes and histiocytes. Regression could be divided into four more or less identifiable stages, associated with different subsets of lymphocytes and monocyte-macrophage lineage cells. Stage I (preregression): nests of unremarkable nevus cells were surrounded by a moderate number of T lymphocytes (relatively small percentage of helper inducer T cells), occasional B cells and macrophages. Stage II (early regression): large number of T lymphocytes and FXIIIa-positive cells were in close contact with nevus cell clusters which showed ragged edges. Lysozyme-positive cells and epidermal Langerhans cells were mildly increased. Stage III (late regression): single nevomelanocytes showing mild atypia were present. Numerous T lymphocytes and macrophages positive for lysozyme, KP1 and/or FXIIIa were interspersed between the nevus cells. Increased numbers of epidermal Langerhans cells were present. Stage IV (complete regression): no nevus cells were observed and moderate numbers of T lymphocytes only remained. These results suggest that T cells, especially T-suppressor cells, and different subsets of macrophages participate in the regression of the nevi.

Is there a decline in picture naming with advancing age?

This review of 25 studies of the picture-naming accuracy of normal aging individuals shows that an age-related decline in picture naming is an inconsistent finding. Naming performance of older adults varied throughout the studies reviewed in this paper. This variability is attributed to the research methods used and to subject characteristics. To date, there are no studies that have considered all "nuisance factors" (e.g., health status, medication) in such a way that would allow support for a decrease in picture-naming accuracy associated with primary aging.

Lymphocyte and macrophage subsets in active and inactive lesions of lichen planus

Lichen planus (LP) is a mucocutaneous disease for which the etiology and pathogenesis are poorly understood. We performed an immunohistochemical study on formalin-fixed tissue sections of 10 cases of LP using subsets of antibodies to lymphocytes (LCA, CD3, OPD4-CD4, L26, LN1 and Leu-7), and monocyte-macrophages [lysozyme, KP1-Mac, Factor XIIIa (FXIIIa) and S-100 protein]. Six cases showed typical histological features of active LP, two cases showed features of active and inactive LP, and two cases showed only inactive LP. In active LP, scattered T cells (CD3+ and pan T cells) were present in the epidermis, whereas large numbers of CD3+ T cells were present at the dermoepidermal junction and in the dermis. Approximately 40% of the T cells at the dermoepidermal junction were of the helper/inducer subset, whereas approximately 80% of those in the dermis were CD4 positive (helper/inducer T cells). Occasional B cells were present in the dermis only. Increased numbers of S-100-positive Langerhans cells, macrophages expressing lysozyme, and FXIIIa dendritic cells were present in the epidermis and dermis. The inactive lesions showed the presence of a few epidermal Langerhans cells and a mild infiltrate of T cells (helper/inducer subset). These results suggest that in addition to different subsets of T cells and macrophages, including Langerhans cells, dermal dendritic cells expressing Factor XIIIa and lysozyme-positive histiocytes play an important role in lichen planus. They may participate in the destruction and subsequent regeneration of the basal layer of the epidermis, or alternatively may be activated as a result of destruction of the basement membrane in LP.

Overexpression of p53 is a late event in the development of malignant melanoma

Overexpression of the p53 gene product has been observed in a high percentage of malignant melanomas. To evaluate the role of this protein in the development of melanoma, we examined p53 expression in benign, premalignant, and malignant melanocytic lesions. Using the antibodies DO-7 and 1801, which recognize both wild-type and most mutant forms of the p53 protein, we analyzed by immunohistochemical staining 26 benign nevi, 34 dysplastic nevi from patients at low risk for the development of melanoma, 22 dysplastic nevi from patients at high risk for the development of melanoma, 61 primary melanomas (including 15 that arose from dysplastic nevi), and 10 metastatic melanomas. Expression of the p53 protein was not observed in any of the benign or dysplastic nevi. Of the primary melanomas only 3 (5%) demonstrated nuclear staining, whereas 70% of the metastatic melanomas showed a positive reaction for p53. These data suggest that overexpression of the p53 gene product is a late event in the progression of melanoma and consequently indicate that expression of this protein cannot be used as a marker to identify patients at high risk for the subsequent development of melanoma.

Subcellular localization of HMFG2 in breast carcinomas: an immunohistochemical and immunoelectron microscopic study

Malignant transformation of human cells is associated with morphological and biochemical alterations. We have studied the distribution and pattern of staining of HMFG2 (human milk fat globulin) in normal breast, benign breast lesions, and 137 primary and metastatic breast carcinomas. Immunohistochemical staining was performed with an antibody to HMFG2 using the indirect peroxidase technique. Three patterns of staining were noted: 1) secretion and luminal staining (in normal breast, most benign breast lesions and some breast carcinomas); 2) plasma membrane staining (in breast carcinomas); 3) intracytoplasmic staining (in breast carcinomas). Immunoelectron microscopy was also performed on normal breast, infiltrating duct, and lobular carcinomas. Immunoelectron microscopy showed localization of the gold particles on the electron dense granules of the HMFG2 protein. These were localized along the surface of the extracytoplasmic lumina in normal breast ducts/acini and breast carcinomas, whereas localization was also noted within the intracytoplasmic lumina in cancer cells only. These results show that there is altered localization of milk fat globulin in breast cancer cells associated with membrane internalization and formation of intracytoplasmic lumina. This contributes to the understanding of the phenotypic alterations associated with malignant transformation in breast cancer.

The correlation of Ki67 growth factor and ERICA in breast cancer

Estrogen receptor (ER) status is an accepted prognostic indicator for breast cancer when measured by either the biochemical or immunohistochemical (ERICA) methods. Moreover, ERICA was found to be a better predictor of survival in human breast cancer than the biochemical assay for ER. The antibody to Ki67 recognizes the growth fraction of proliferating cells. We examined 100 primary breast cancers to investigate the relationship between ER status as measured by ERICA and Ki67 reactivity. Of the 56 ERICA positive cases, 47 (84%) were Ki67 negative whereas 30 of the 44 ERICA negative tumors were Ki67 positive (68%). There was evidence of a significant inverse relationship between ERICA and the growth fraction (77% of cases, p less than 0.001). In addition, a cluster of ERICA-positive Ki67-positive tumors that were larger and occurred in older patients was identified as a subset that might require aggressive therapy. Our results suggest that Ki67 may be an important additional criterion for predicting the biological behaviour of breast cancers.

Altered distribution of desmin filaments in hypertrophic cardiomyopathy: an immunohistochemical study

Hypertrophic cardiomyopathy (HCM) is characterized by myofiber hypertrophy and disarray. Intermediate filaments play an important role in maintaining of normal cell shape. Desmin filaments have been detected in adult cardiomyocytes, and vimentin and keratin filaments in cardiomyocytes during embryonic development. The pattern of arrangement of intermediate filaments in HCM has not been reported. We examined the distribution of intermediate filaments in formalin-fixed tissue sections of the disarrayed myofibers from 10 hearts with HCM using an immunohistochemical technique and antibodies to desmin, vimentin, and high and low molecular weight keratins. The controls consisted of subaortic tissue from surgically explanted hearts of patients with ischemic heart disease. In the ischemic hearts, desmin was detected in the Z bands and intercalated disks. In all HCM cases, three patterns of staining for desmin were noted: (a) individual myocytes showing a parallel arrangement along Z bands; (b) focal myofibers with decreased or complete loss of labeling of Z bands; and (c) individual myocytes with intense granular cytoplasmic staining especially in disarrayed myofibers. No staining for vimentin or keratins was noted in the cardiomyocytes from either the HCM or ischemic cases. The altered arrangement of desmin filaments in the disarrayed cardiac muscle fibers may play a role in the altered contractility that occurs in patients with HCM.

Lymphocyte markers on formalin-fixed tissue in Jessner's lymphocytic infiltrate and lupus erythematosus

Clinical and histological differentiation between Jessner's lymphocytic infiltration of the skin (JLI) and lupus erythematosus (LE) may be difficult. Previous immunohistochemical studies using monoclonal antibodies on frozen sections have shown that the majority of inflammatory cells in JLI and LE are T lymphocytes, whereas B lymphocytes are few or absent. We have performed an immunohistochemical study on formalin-fixed, paraffin-embedded tissue sections from seven patients with JLI and five with LE using monoclonal antibodies MT1 (pan T-cells), OPD4 (helper/inducer T-cells CD4), MT2 (mantle zone B and some T-cells), MB2 (pan B-cells), L26 (pan B-cells), and LN1 (germinal centre B-cells). In both diseases, the-majority of the inflammatory cells were T lymphocytes (MT1 positive), confirming the results others have obtained on frozen material. OPD4 positive cells were detected in varying numbers in all cases. However, the percentage of B lymphocytes tended to be higher in JLI than LE. LN1 was the most useful B-cell marker in distinguishing JLI from LE. However, a combination of MT2 and LN1 gave the most significant difference. We conclude that immunohistochemical analysis using a panel of monoclonal antibodies to T and B lymphocytes may be useful in differentiating JLI from LE, although there is still considerable overlap.

Expression and amplification of neu oncogene in pleomorphic adenomas of salivary gland

Amplification of the neu oncogene and overexpression of its product was found to be a potential marker for aggressive biological behavior in breast cancer. However, the expression of the neu oncoprotein in normal breast ducts and myoepithelial cells has also been demonstrated. Hence, we examined normal salivary gland tissue and 15 cases of pleomorphic adenoma for the expression of the neu oncoprotein by immunohistochemistry using two polyclonal antibodies and 12 cases for the amplification of the neu oncogene using slot blot hybridization. Immunohistochemistry in the normal salivary gland revealed positive staining of all ductal cells. In the pleomorphic adenomas all cellular elements stained to a variable degree. The positive staining was seen in the ductal cells, in the solid sheets, and in chondroid, myxoid, and metaplastic foci. The normal salivary gland and 11 of 12 cases of pleomorphic adenoma showed no increase in copy number of the neu oncogene, whereas one case showed threefold amplification. These results indicate that the neu oncoprotein is expressed but the neu copy number is not increased in normal salivary gland epithelium and in most pleomorphic adenomas. The threefold amplification of the gene in one case may indicate an aggressive biological behavior.

Acalculia: an historical review of localization

This article reviews the brain localization of calculation disorders (acalculia) beginning with Gall's claim in the early 19th century for a "center" of calculation. A renewed interest in the subject arose around the time of Henschen during the first quarter of the 20th century. A summary of the cases of acalculia since Henschen leads to the conclusion that regardless of the functional modular nature of calculation ability, there is neither a localized region nor a specific hemisphere uniquely underlying the disorder.

Immunoreactivity of S100 beta in heart, skeletal muscle, and kidney in chronic lung disease: possible induction by cAMP

S100 protein is a calcium-binding protein composed of two subunits S100 alpha and S100 beta, which are expressed selectively by specific cell types. The distribution of S100 beta was examined among various tissues obtained at autopsy from 18 subjects with chronic lung disease and 10 control subjects. The presence of S100 beta in individual cell types was demonstrated by immunoperoxidase staining using polyclonal and monoclonal antibodies specific for S100 beta. In the 10 control subjects, positive staining was seen in a number of cell types that normally produce S100 alpha and S100 beta, (e.g., glial cells, melanocytes, chondrocytes) or only S100 beta, (e.g., Schwann cells). There was no staining of myocardial cells, skeletal muscle fibers, or kidney tubules, which normally produce S100 alpha but not S100 beta. In contrast, in the 18 subjects with chronic lung disease, all of the above cell types stained positively for S100 beta, showing that in these subjects cell types that ordinarily expressed only S100 alpha also expressed S100 beta. We suggest that the observed induction of S100 beta in these cell types seen in subjects with chronic lung disease was mediated by an elevation of cAMP levels secondary to bronchodilator therapy with beta-adrenergic agonists and phosphodiesterase inhibitors.

Heterogeneity in expression of S100 beta mRNA in human melanoma and pleomorphic adenoma demonstrated by in situ hybridization

S100 protein is a widely used immunohistochemical marker for identification of a number of tumors including malignant melanoma and pleomorphic adenoma of the salivary gland. To extend the detection techniques for S100 protein to the level of its mRNA, sections of malignant melanoma and pleomorphic adenoma were hybridized in situ with a 35S-labeled anti-sense RNA probe complementary to the mRNA for the beta subunit of human S100 protein. Both tumors were labeled with the anti-sense RNA probe but not with a sense RNA probe. In addition, sections of normal and tumor tissues which were known not to express S100 protein on the basis of immunohistochemical studies were not labeled with the anti-sense RNA probe. These results established the specificity of the in situ hybridization technique for the detection of S100 protein mRNA. Although most of the tumor cells in both malignant melanoma and pleomorphic adenoma were labeled with the anti-sense RNA probe, unlabeled tumor cells were also present in their vicinity, suggesting there was a heterogeneity among the cells in both tumor types with respect to S100 protein mRNA expression.

Immunohistochemical demonstration of actinically damaged elastic fibers in keratoacanthomas: an aid in diagnosis

The inclusion of elastic fibers within the epithelium of keratoacanthomas is a phenomenon suggested to be an aid in differentiating this lesion from squamous cell carcinoma. Antilysozyme antibodies have recently been noted to stain actinically damaged elastic fibers but not those from sunprotected skin. In this study, 54 keratoacanthomas and 46 squamous cell carcinomas were stained with a histochemical elastic tissue stain and polyclonal antibody to lysozyme using an immunoperoxidase technique. Elastic fibers were demonstrated in keratoacanthomas (37/54, 68%) significantly more often than squamous cell carcinomas (12/46, 26%) (p less than 0.001) using both techniques. This study confirms that the inclusion of elastic fibers occurs significantly more often in keratoacanthomas than squamous cell carcinomas. These elastic fibers were also actinically damaged, suggesting a role for sun damage in the evolution of keratoacanthoma.

Lysozyme in abnormal dermal elastic fibers of cutaneous aging, solar elastosis and pseudoxanthoma elasticum

Staining of elastic fibres with antilysozyme antibodies has been noted previously. In this study, we examined the staining pattern of dermal elastic fibres in aging, solar elastosis, and lesional skin of pseudoxanthoma elasticum (PXE) using an antibody to lysozyme and the indirect-peroxidase technique. To assess the effects of aging, sun-protected skin (buttock) from a younger and an older group of patients was used. Sun damage was studied in skin specimens from varying sun-exposed body regions (trunk; head and neck). No staining was seen in sun-protected skin from younger individuals, whereas sun-protected skin from older persons had scattered positive fibres. Solar elastotic material was intensely positive and the number of positive fibres appeared to correlate with the amount of sun damage. Abnormal elastic fibres in PXE also stained positively, but less intensely, than fibres in solar elastosis. This study shows that changes in the elastic fibres due to degenerative processes or genetic factors results in altered antigenic expression of the fibres. This may be an epiphenomenon secondary to changes in proteoglycans, which are known to occur with solar elastosis and PXE, or may represent an adaptive phenomenon to maintain the elastic properties of the altered fibres or to decrease their antigenicity.

S-100 protein antibodies do not label normal salivary gland myoepithelium. Histogenetic implications for salivary gland tumors

Neoplastically modified myoepithelial cells have a key role in developing the histologic characteristics of some salivary gland tumors. S-100 protein expressed in certain of these tumors is suggested to support this role, as the principal component in the human salivary gland reported to be S-100 protein-positive is myoepithelium. Confirmation of such an important aspect is required. Immunoperoxidase staining of parotid salivary gland shows considerably different patterns obtained with antibodies to S-100 protein, neuron-specific enolase, and neurofilaments compared with those for muscle-specific actin and cytokeratin 14; many more cells and their processes associated with acini and ducts are evident with the latter two antibodies. Double immunofluorescent staining with antibodies to either S-100 protein or neuron-specific enolase combined with muscle-specific actin does not reveal colocalization of these antigens in myoepithelial cells. The former localize only to nerve fibers adjacent to, but separate from, acini, and the latter only to myoepithelial cells. It is apparent that S-100 protein staining of the rich network of unmyelinated nerves in the interstitial tissues, evident ultrastructurally, has been misinterpreted as myoepithelium. This result has important implications for histogenetic classifications of salivary gland tumors.

Distribution and patterns of staining of Neu oncogene product in benign and malignant breast diseases

Amplification of the Neu oncogene (c-erbB-2) has been reported by various researchers as a marker for poor clinical outcome in patients with breast cancer. We have performed immunohistochemical staining using a polyclonal antibody to the Neu oncoprotein on formalin-fixed material from normal breast, benign breast lesions, and 102 stage I node-negative breast cancers. Hybridization studies were also performed on 66 of the breast cancer cases. In the cancers 33% of cases showed positive staining of the in situ and invasive component, whereas only 25% of cases showed amplification of the Neu oncogene. The staining pattern in the tumor cells was cytoplasmic with plasma membrane accentuation. Focal positive cytoplasmic staining was noted in some cases of fibrocystic disease, fibroadenoma, and normal breast duct epithelium. Myoepithelial cells and smooth muscle of blood vessels also showed a positive reaction. This study shows that the Neu oncoprotein can be demonstrated on formalin-fixed material from normal, benign, and malignant breast lesions. In the breast cancers the differences in the number of cases showing amplification and those showing a positive immunohistochemical reaction could be due to increased transcriptional activity. It is possible that the node-negative patients whose tumors express the Neu oncogene may correspond to the group of patients who are expected to have a poor prognosis.

Immunohistochemistry of intravascular papillary endothelial hyperplasia

Intravascular papillary endothelial hyperplasia is an interesting endothelial proliferation, the nature of which has aroused some controversy. Five cases were studied by light microscopy and by immunohistochemistry using antibodies to Factor VIII-related antigen (FVIII-rAg), ferritin, alpha 1-antitrypsin, alpha 1-antichymotrypsin and vimentin and were compared with conventional intravascular organizing thrombi. The results show a similar progression of the immunophenotype of the endothelial cells in both entities: they are initially positive for ferritin, then acquire vimentin positivity and only display FVIII-rAg positivity in advanced ("mature") lesions. This suggests that intravascular endothelial hyperplasia is closely related to organizing thrombi and is probably a peculiar form thereof.

Monoclonal antibody MT1: a marker for Langerhans cell histiocytosis

Langerhans cells and their pathologic counterparts can be identified in paraffin sections using immunohistochemical staining for S-100 protein. This procedure is useful in confirming a diagnosis of Langerhans cell histiocytosis (LCH). However, many other cell types are also positive for S-100 protein. Positive staining for CD1 (Leu 6) supports a diagnosis of LCH, but requires frozen tissue. A panel of antibodies would be desirable in confirming a diagnosis of LCH, particularly if these antibodies could be used on paraffin-embedded material. We studied the pattern of staining for commercially available monoclonal antibodies MT1, MT2, MB2, and LN1, which were originally marketed as lymphocyte markers, using paraffin-embedded tissue sections of cases of LCH. In all 20 cases pathologic Langerhans cells stained positively with MT1 only. Various other S-100 protein-positive lesions were also examined with MT1 and were consistently negative for MT1. Other cutaneous histiocytic and mast cell lesions were positive with MT1, but S-100 protein negative. Our results demonstrate that the monoclonal antibody MT1 serves as an additional marker for LCH and, together with S-100 protein, would make up a diagnostic panel of antibodies for LCH to be used on routine paraffin-embedded sections.

Cystosarcoma phylloides of the breast and its mimics. An immunohistochemical and ultrastructural study

Cystosarcoma phylloides of the breast is a tumor composed of breast ducts and a cellular stromal component that can be benign or malignant. The origin of the stromal cells is controversial. We undertook an immunohistochemical and ultrastructural study of 11 cases of cystosarcoma phylloides to assess the histogenesis of the stromal component. By light microscopy, 4 were diagnosed as benign, and 7 were diagnosed as malignant. Antibodies to vimentin, desmin, actin, high- and low-molecular-weight keratins, and S100 protein were used for immunohistochemical staining. In the 4 benign cases of cystosarcoma phylloides, the stromal cells stained positively only for vimentin. In the malignant tumors, the spindle cell component stained for vimentin in all the cases. In addition, the malignant stromal cells coexpressed desmin in two cases and keratin and S 100 protein in another case. By electron microscopy the stromal component in the benign case and in two of five malignant cases was composed of a mixture of fibroblasts and myofibroblasts. The entire neoplastic stroma in two other malignant cases showed features of smooth-muscle differentiation, whereas in another case all the stromal cells showed myoepithelial differentiation. Thus, in benign and malignant cystosarcoma phylloides, the stromal component consists of a mixture of fibroblasts and myofibroblasts. Leiomyosarcomas and myoepitheliomas can mimic malignant cystosarcoma phylloides, but immunohistochemistry and electron microscopy can differentiate these entities. This is important since their biologic behavior is different.

Nucleolar organizer regions in superficial spreading melanoma with nodule

Nucleolar organizer regions (NORs) are genes coding for the ribosomal RNA; they also induce the formation of the nucleolus at interphase. Transcriptionally active NORs can be visualized in histological sections with a silver colloid method, allowing direct counting of these structures (so-called AgNORs). Seven superficial spreading melanomas with nodule (i.e., melanomas containing both a radial and a vertical growth phase) were studied with the technique. The nuclear AgNOR counts (mean +/- SEM) were 5.44 +/- 1.70 for the radial growth phase and 7.65 +/- 2.35 for the vertical growth phase (P less than 0.01). This difference in mean nuclear AgNOR numbers may be related to other known differences in the biological behavior of the two growth phases.

Primary multilobulated B-cell lymphoma of the breast

Malignant lymphomas with multilobulated nuclei are recently recognized neoplasms. We report a case of multilobulated B-cell lymphoma arising in the breast. The light microscopic, electron microscopic, and immunohistochemical features are described and compared with those of previously reported T- and B-cell multilobulated lymphomas from other sites. A follicular center cell origin of this lymphoma is postulated. To our knowledge, this is the first report of a primary multilobulated lymphoma of the breast.

Palisaded encapsulated neuroma: an immunohistochemical study

Ten palisaded neuromas of the skin were studied immunohistochemically for the presence of S-100 protein, epithelial membrane antigen, neurofilaments, glial fibrillary acidic protein, and positivity with the Leu-7 monoclonal antibody. In all cases, the fascicles of tumor cells were positive for S-100 protein and negative for epithelial membrane antigen; the tumor capsules were negative for the former in all cases but positive for the latter in seven of ten cases. In three lesions, epithelial membrane antigen-positive cells formed sheaths around fascicles of tumor cells. Axons were demonstrated by anti-neurofilament antibody in seven lesions. None of the lesions stained for glial fibrillary acidic protein. All of them showed positivity with the Leu-7 antibody, which stained both tumor spindle cells as well as membranous profiles consistent with myelin sheaths. These results indicate that the tumor is composed of cells of schwannian differentiation whereas the capsule and sheaths surrounding intratumoral fascicles are of perineurial origin. They also indicate the presence of axons, some of which are myelinated. Our findings support the concept of a close relationship between palisaded and traumatic neuroma.

Primary malignant lymphoma of the spleen in systemic lupus erythematosus

Malignant lymphoma has been infrequently reported in the course of systemic lupus erythematosus (SLE). We report a case of primary malignant lymphoma of the spleen, an unusual site of primary lymphoma, complicating the course of systemic lupus erythematosus (SLE). Our patient had been treated with low dose prednisone and hydroxychloroquine only, and her lupus was quiescent at the time of presentation with the lymphoma. Thus primary malignant lymphoma should be considered in the differential diagnosis of splenomegaly in SLE.

Epithelial proliferation in thymic hyperplasia. An immunohistochemical study and correlation with the developing fetal thymus

Thymic hyperplasia is a B-cell lymphoid proliferation in which an epithelial component has not, to our knowledge, been previously described. We present a case of thymic hyperplasia in which numerous lymphoid follicles with germinal centers were partially surrounded by small sheets of spindle and epithelioid cells. Electron microscopy confirmed the epithelial nature of these cells. Immunostaining was performed using antibodies to keratins, S100 protein, and two B-cell markers, LN1 and MB2. The proliferated epithelium stained only for high-molecular-weight keratin, whereas the lymphoid tissue stained positively for both B-cell markers. To determine the origin of the proliferated epithelium, the staining was compared with that of the developing fetal and normal adult thymus. We have shown that during fetal development, the keratin composition of thymic epithelium changes from staining predominantly with low- to high-molecular-weight keratin. The immunostaining characteristics of the epithelium in this case of thymic hyperplasia suggest an origin from adult-type epithelium. Furthermore, the association of S100-positive interdigitating reticulum cells with the proliferated epithelium suggests that it is of medullary origin. Our results indicate that epithelial proliferation can be an important component of thymic hyperplasia.

Monoclonal antibody to a human pancreatic carcinoma cell line recognizes gastrointestinal neoplasms

A monoclonal antibody designated RWP1.1 was produced against a human pancreatic carcinoma cell line RWP1. This antibody was shown to recognize an epitope of carcinoembryonic antigen. The reactivity of the antibody was evaluated on formalin-fixed normal tissues, 86 malignant neoplasms, 10 colonic polyps, and 6 cases of chronic pancreatitis using the peroxidase anti-peroxidase technique. RWP1.1 did not react with normal tissues apart from weak staining of fetal pancreatic ducts. This antibody preferentially reacted with primary and metastatic adenocarcinomas of the colon, stomach, pancreas, and colonic polyps but not with most adenocarcinomas from other sites nor with other types of tumors or cases of chronic pancreatitis. It also reacted with colon adenocarcinomas on frozen sections. The restricted specificity of this antibody could be used in differentiating gastrointestinal adenocarcinomas from other types of tumors including adenocarcinomas from other sites and most pancreatic adenocarcinomas from chronic pancreatitis.