[Diagnostic image (396). A woman with an eczematous nipple]

A 58-year-old woman presented with an eczematous lesion of the right nipple 6 months after a right axillary lymph node dissection that was performed due to a metastatic carcinoma. The nipple scrape smear showed malignant cells compatible with Paget's disease.

Identification of markers for nipple epidermis: changes in expression during pregnancy and lactation

In vertebrates, specific regions of skin crucial for interaction with and manipulation of elements in the environment are characterized by specialized epidermis. Regions of specialized epidermis show distinct patterns of cellular differentiation and express specific keratins that provide an increased ability to withstand mechanical strain. The nipple, which must endure the mechanical strain of nursing, is a type of specialized epidermis. The entire ventral skin of the keratin 14 promoter driven PTHrP mouse provides a model for nipple development. To identify novel markers for this specialized epidermis, we have used two-dimensional (2-D) gels, mass spectrometric protein identification, Western blotting and immunohistochemistry to compare intermediate filament preparations from the nipple-like K14-PTHrP ventral skin to that of wild-type littermates. We identified 64 spots on 2-D gels that were increased in expression in the nipple-like skin of the female K14-PTHrP mouse and 11 spots that were elevated in the wild type. Microsequencing suggested that K17 and epiplakin were among the proteins with the greatest increase in expression in the K14-PTHrP ventral skin. Using Western blots and immunohistochemistry, we evaluated the expression of these proteins as well as K6 in the wild-type nipple, K14-PTHrP ventral skin and wild-type ventral skin. In addition, we found that the expression of K6 was minimally changed in the pregnant and lactating nipple, but the expression of a previously identified marker, K2e, was reduced during lactation. Using a model of the mechanical strain induced by nursing, we found that K2e but not K6 expression was responsive to this condition. The identification of epidermal markers and their expression patterns will provide insight into the cellular differentiation patterns of the nipple and the underlying epidermal-mesenchymal interactions that direct this differentiation.

Correlation of nipple aspiration and ductal lavage cytology with histopathologic findings for patients before scheduled breast biopsy examination

BACKGROUND

The use of ductal lavage to obtain cells from within the breast ducts has been described for patients at high risk for breast cancer. The purpose of this study was to correlate ductal lavage cytologic findings with the corresponding histology.

METHODS

Twenty-two patients were evaluated and 20 patients underwent ductal lavage followed by breast biopsy examination as a result of positive nipple aspiration fluid. Ductal lavage samples were classified by a cytopathologist as negative, mild atypia, marked atypia, or malignant. A different pathologist interpreted the histologic findings of the biopsy examination.

RESULTS

Adequate specimens for cellularity were obtained in 12 of 22 (53%) patients: 6 of the 12 (50%) had both benign cytology and histology, 2 (16.7%) had benign cytology with atypical ductal hyperplasia or atypical lobular hyperplasia on histology, 2 (16.7%) had marked atypia on cytology and benign histology, and 2 (16.7%) had malignant cytology and benign histology. The specificity of the procedure was 83.4%.

CONCLUSIONS

Ductal lavage yielding an adequate sample for analysis was successful in only 52% of patients. Of those, the cytologic-histologic correlation was discordant in 50%. The role of ductal lavage in accurately predicting lesions present on subsequent breast histologic evaluation of planned biopsy examinations requires further investigation.

Reproducibility of cytologic atypia in repeat nipple duct lavage

BACKGROUND

It is believed that atypical cells identified by nipple duct lavage (NDL) indicate an increased risk for breast carcinoma similar to atypical ductal hyperplasia diagnosed by tissue biopsy, but many basic performance characteristics of NDL currently are undefined.

METHODS

NDL was performed in 108 patients unselected for breast carcinoma risk and then was repeated after 2-14 months (median, 8 months) if the initial lavage was classified as atypical. Breast magnetic resonance images (MRIs) were obtained from a subset of patients who had atypical lavage results.

RESULTS

Marked atypia was diagnosed in 22% of 36 breasts with an incident carcinoma compared with 7% of 172 unaffected breasts (P = 0.01). After excluding breasts with an incident carcinoma, there were 32 patients (30%) with either mild or marked atypia. The lavage was repeated in 23 of these women, and the second lavage was classified as atypical in 48%. Neither marked atypia on the initial lavage nor a 5-year Gail risk > or = 1.7% predicted atypia on repeat lavage, but there was a trend for improved reproducibility when the atypia initially was diagnosed in a fluid-producing duct. MRIs were abnormal in 13% of 24 breasts with an atypical lavage, and ductal carcinoma in situ was diagnosed subsequently in 1 breast.

CONCLUSIONS

Atypia frequently is diagnosed by NDL, but the reproducibility of repeat lavage is low. Lavage atypia may be physiologic or artifactual rather than pathologic in many instances. Marked atypia occasionally may represent mammographically occult ductal carcinoma in situ.

Cytologic findings and protein expression profiles associated with ductal carcinoma of the breast in ductal lavage specimens using surface-enhanced laser desorption and ionization-time of flight mass spectrometry

BACKGROUND

Early detection of breast carcinoma enhances the chances for patient survival. The authors' work focused on an innovative technique that couples breast ductal lavage (DL) with surface-enhanced laser desorption and ionization-time of flight mass spectrometry (SELDI-TOF MS) to yield a highly sensitive and specific method of breast carcinoma detection.

METHODS

The study group included 16 women who had unilateral, biopsy-proven breast carcinoma. Studying paired DL specimens from each woman (the breast with and the breast without carcinoma), a cytologic investigation was performed on the cells present in the DL samples, and the protein content of the DL fluid was analyzed with the SELDI-TOF MS technique using the strong anionic exchange chip surface.

RESULTS

Only 5 of 16 DL specimens (31%) from breasts with biopsy-proven carcinoma contained malignant cells, whereas the remaining samples contained only histiocytes and clusters of benign ductal epithelium. In contrast, 12 of 16 DL specimens (75%) from breasts that contained carcinoma had a different protein peak pattern compared with the paired DL specimen from the same patient's contralateral, uninvolved breast. This finding was independent of the presence of neoplastic cells in the lavage fluid. In addition, specific protein peaks, which may represent potential biomarkers, were identified in the DL fluids from breasts with carcinoma. Some of these peaks were conserved between different patients.

CONCLUSIONS

The combination of breast DL with SELDI-TOF MS offers a unique and powerful technique for the detection and monitoring of breast carcinoma. This method has the potential to enhance the diagnostic utility of conventional DL cytology.

Nipple-areolar pigmentation: histology and potential for reconstitution in breast reconstruction

The makeup of nipple-areolar skin, in terms of its melanin and melanocyte content has not previously been established. This histological information is required if pigmentation of the reconstructed nipple-areola is to be successful in post-mastectomy breast reconstruction. We describe examination of 200 parallel sections of nipple-areolar skin of 20 women using histochemical (Masson-Fontana) and immunohistochemical (Mel-5) techniques, evaluated using quantitative image analysis. The amount of melanin present per length of basement membrane was 2.14 times higher in areolar skin than breast skin. The ratio of melanocytes to keratinocytes was 1:9.7 in areolar skin vs. 1:14.7 in breast skin. We also describe a cell culture and skin construct method using autologous human serum without toxic growth promoting additives, which could be used in the clinical setting of nipple-areolar reconstruction.

Feasibility of breast duct lavage performed by a physician extender

BACKGROUND

The safety and feasibility of ductal lavage (DL), a risk-assessment tool utilizing a minimally invasive technique that permits sampling of breast duct epithelium, performed primarily by a nurse practitioner (NP), was studied prospectively.

METHODS

Women at high risk for breast cancer with a normal clinical breast exam and mammogram were enrolled. Nipple aspirate fluid (NAF)-yielding ducts were identified, cannulated, and lavaged primarily by an NP in collaboration with a breast surgeon. Samples with sufficient cellularity were categorized as benign, mild atypia, marked atypia, or malignant. Pain and adverse events were recorded.

RESULTS

Thirty-seven women, with a mean age of 51.7 years, were enrolled. Thirty-one (83.8%) women yielded NAF and, of those, 28 (90.3%) had one or more ducts successfully cannulated. Of 65 lavaged ducts in these 28 women, cellularity was adequate for diagnosis in 44 (67.7%) samples. Cytologic findings were as follows: 24 benign, 15 mild atypia, 4 marked atypia, and 1 malignant. The procedure was well tolerated with a mean pain score of 3.2 (SD +/- 1.81). The most frequent adverse event was breast fullness, reported by 44.8% of the women. Two women with marked atypia were evaluated further and found to have intraductal papillomata. The woman with malignant cytology had ductal carcinoma in situ.

CONCLUSION

DL is a safe, generally well-tolerated procedure that can be performed successfully by a trained NP.

Anatomy of the nipple and breast ducts revisited

BACKGROUND

Increasing interest in the intraductal approach to the breast has necessitated revisiting the anatomy of the breast.

METHODS

Using six different complementary in vivo and in vitro approaches, the authors determined the number, distribution, and anatomic properties of the ductal systems of the breast, which extend from the nipple orifices to the terminal duct lobular units.

RESULTS

More than 90% of all nipples examined contained 5-9 ductal orifices, generally arranged as a central group and a peripheral group. Each nipple orifice communicated with a separate, nonanastomosing ductal system, which extended to the terminal duct lobular unit.

CONCLUSIONS

Increased knowledge of the ductal anatomy of the breast and the ability to access the nipple ductal orifices will provide a foundation for the intraductal approach to the breast.

Feasibility and utility of using chromosomal aneusomy to further define the cytologic categories in nipple aspirate fluid specimens

BACKGROUND

There is renewed interest in using the cytologic changes in the epithelial cells obtained from specimens such as nipple aspiration fluid (NAF) and ductal lavage for risk stratification of women at increased risk for developing breast carcinoma.

METHODS

Molecular tests such as fluorescence in situ hybridization (FISH) have the potential to be used as adjuncts to conventional cytology for more accurately categorizing cells in these types of specimens. The current study investigated the feasibility and utility of FISH analysis of aneusomy in chromosomes 1, 8, 11 and 17 as an adjunct to conventional cytology in the classification of NAF specimens.

RESULTS

The authors found chromosomal aneusomy for at least one chromosome in all three malignant and both markedly atypical cases. Of the five cases classified as being mildy atypical on cytology, four were disomic, and only one showed aneusomy in chromosomes 8 and 11.

CONCLUSIONS

The current study established the possibilities, limitations, and feasibility of using FISH in conjunction with routine cytology for a more accurate classification of ductal epithelial cells in NAF specimens. FISH-based detection of chromosomal aneusomy helped to define mild atypia, thereby aiding in the selection of the truly atypical cases for appropriate therapeutic intervention. In addition, FISH-based detection of chromosomal aneusomy can also be a valuable adjunct to conventional cytology in selected cases for confirming a benign, suspicious, or malignant diagnosis.

Detection of LOH and mitochondrial DNA alterations in ductal lavage and nipple aspirate fluids from hngh-risk patients

We describe a method for the isolation of free DNA from ductal lavage (DL) and nipple aspirate fluid (NAF), and its evaluation for the presence of LOH at the BRCA1 and FHIT genes and for mitochondrial DNA (mtDNA) mutations at the D310 marker, to improve early detection of breast cancer. We evaluated 26 DL and six NAF samples from 14 women of known BRCA1 status, who have no clinical evidence of breast tumors: nine mutation carriers and five non-carriers. LOH studies at the BRCA1 locus were possible in 19/26 DL samples, and at the FHIT locus in 16/26 samples. In 4/9 mutation carriers we found LOH at the BRCA1 allele, and in two of these we also found LOH at the FHIT allele. In one of the mutation carriers with BRCA1 LOH, invasive breast cancer was subsequently detected, and the tumor showed the same LOH as the DL. In one of the true negatives, BRCA1 and FHIT LOH were detected. The mitochondrial studies were possible in all 26 DL samples and a somatic mutation was found in 3/9 carriers, two of whom also had LOH at the BRCA1 locus, and in none of the non-carriers. mtDNA mutation evaluation was possible in 4/6 NAF samples. The NAF and DL results were concordant. One NAF sample from a BRCA1 patient showed a mtDNA mutation. Our data demonstrates the feasibility of performing molecular studies using the free DNA present in the ductal fluid, while the intact cells can be used for cytologic studies.

Ductal lavage and its histopathologic basis: A cautionary tale

Ductal lavage has been touted as a possible screening tool for patients with a high risk for the development of breast cancer. This article examines the fundamental concepts underlying the procedure and critically evaluates its possible utility in light of the known molecular and surgical pathologic data. It highlights the fact that risk assessment in breast cancer is far from an exact science, since most women who develop breast cancers are not identified as high-risk by the Gail model. The utility of ductal lavage has as yet not been proven, and even if it were useful, it is likely to benefit only a subset of all breast cancer patients. Further studies, preferably controlled clinical trials, are necessary before routine use of the procedure can be recommended.

Cytology of ductal lavage fluid of the breast

The cytologic evaluation of nipple aspirate fluids has been shown to identify women at increased risk for developing breast cancer. One limitation of this assay is the often scant cellularity of the specimen. An improved technique, ductal lavage, utilizes a microcatheter inserted into individual breast ducts to collect large numbers of cells for cytologic evaluation. Epithelial cells in ductal lavage fluids can be categorized as benign, malignant, or showing mildly or markedly atypical changes. The cell characteristics which were most helpful in identifying abnormal cells were related to cell arrangement, cell size, nuclear size, and size variation, nuclear membrane irregularity, chromatin granularity, and the presence of large nucleoli. Cell size, nuclear size variation, and large nucleoli were the most robust features, as determined by agreement between two pathologists. Moderate cell enlargement and the presence of large nucleoli were the features selected by structured tree analysis for classifying the specimens into the diagnostic groups. The similarity of the cytology of ductal lavage fluid to nipple aspirate fluid strongly suggests that these specimens will also be useful for predicting breast cancer risk.

Atypia in the assessment of breast cancer risk: Implications for management

Proliferative disease accounts for as much as one-third of all biopsies for benign disease and 5-10% of proliferative lesions show atypia ductal or lobular hyperplasia. Nearly 40% of women with a family history of breast cancer and atypical hyperplasia subsequently develop breast cancer. A quantitative model developed by Gail and colleagues estimates the probability of developing breast cancer over time. Risk factors in the model include current age, ages at menarche and first live birth, number of previous biopsies, the presence of cellular atypia, and the number of first-degree relatives with breast cancer. Atypical hyperplasia approximately doubles the risk of developing invasive breast cancer within any quantitative risk profile. Ductal lavage provides a minimally invasive method of collecting breast epithelial cells. The procedure opens the possibility of repeatable tracking of breast cytology over time, but its role as a risk assessment tool remains to be fully defined.

Intraductal aspiration cytology and galactography for nipple discharge

The objective of this study was to assess the diagnostic value of preoperative cytology and galactography in women with nipple discharge using a simple intraductal aspiration method. From May 1997 to February 2002, 172 patients with unilateral, spontaneous nipple discharge without palpable masses underwent intraductal aspiration cytology followed by galactography. Major duct excision was performed in 133 of 155 successful cases. Pathological findings showed solitary papilloma in 65 cases, breast cancer in 16 cases, fibrocystic disease in 17 cases, papillomatosis in 12 cases, ductal hyperplasia in 11 cases, and finally, duct ectasia in 12 cases. Our results showed sensitivity of 75.0% and 68.8%, specificity of 86.3% and 62.4%, and overall accuracy of 85.1% and 63.2%, respectively, for cytological analysis and galactography. This suggests that the intraductal aspiration method for preoperative cytology and galactography is a minimally invasive and well-tolerated procedure that seems to be useful in differentiating between benign and malignant lesions in patients with unilateral, spontaneous nipple discharge.

Galactography and exfoliative cytology in women with abnormal nipple discharge

OBJECTIVE

To evaluate galactography and cytology in women with nipple discharge without clinical or mammographic evidence of cancer.

METHODS

During a 12.5-year period, 384 women (15-85 years, mean age 47.5 +/- 14 years) were referred for galactography and smear cytology for recent onset of spontaneous, non-milky nipple discharge. Patients with clinical or mammographic evidence of tumor underwent excisional biopsy directly. Among 314 galactograms, 189 [60.2%; 95% confidence interval (CI) 54.5%, 65.6%] biopsies were recommended. A further 11 patients were scheduled for biopsy because of mammography or cytology.

RESULTS

Sixteen of 182 biopsied patients had malignancies (8.8%; CI 5.3%, 14.1%). Combined rate of papillomas, papillomatous proliferation, and malignant tumors was 59.9% (109 of 182; CI 52.4%, 67.0%). Biopsy was malignant in three of 56 women (5%) with nonhemorrhagic discharge and in 13 of 97 (13%) with hemorrhagic discharge (P =.26). Exfoliative cytology revealed 11 false-negatives, four false-positives, five true-positives, and 153 true-negatives (sensitivity 31.2%, CI 11%, 58%; specificity 97.4%, CI 93%, 99%). In ten of 158 patients (6.3%) with suspicious galactography, cancer was found by biopsy. Sensitivity of galactography for malignancy was 83% (CI 51.6%, 97.9%) and specificity was 41% (CI 35.2%, 46.5%). Galactographic sensitivity for any (benign or malignant) neoplasm was 94% (93 of 99; CI 87%, 98%) and specificity was 55% (119 of 215; CI 48%, 62%). Half of the cancers were detected exclusively by galactography.

CONCLUSION

Cytology is helpful when positive and galactography localizes the source of discharge. Biopsy is indicated when palpation, mammography, cytology, or galactography is suspicious.

Nipple aspiration in diagnosis of breast cancer

It has been shown that early detection of breast cancer saves lives. Mammography and physical examination are currently the most commonly utilized screening methods for breast cancer. Research is being carried out to optimize these screening methods, as well as to develop new techniques. This review summarizes the findings of the research focusing on the diagnostic techniques involving the breast ductal system to date. These tests include nipple fluid cytology, nipple fluid tumor markers, ductogram, and ductoscopy.

Parathyroid hormone-related protein maintains mammary epithelial fate and triggers nipple skin differentiation during embryonic breast development

Prior reports have demonstrated that both parathyroid hormone-related protein (PTHrP) and the type I PTH/PTHrP receptor are necessary for the proper development of the embryonic mammary gland in mice. Using a combination of loss-of-function and gain-of-function models, we now report that PTHrP regulates a series of cell fate decisions that are central to the survival and morphogenesis of the mammary epithelium and the formation of the nipple. PTHrP is made in the epithelial cells of the mammary bud and, during embryonic mammary development, it interacts with the surrounding mesenchymal cells to induce the formation of the dense mammary mesenchyme. In response, these mammary-specific mesenchymal cells support the maintenance of mammary epithelial cell fate, trigger epithelial morphogenesis and induce the overlying epidermis to form the nipple. In the absence of PTHrP signaling, the mammary epithelial cells revert to an epidermal fate, no mammary ducts are formed and the nipple does not form. In the presence of diffuse epidermal PTHrP signaling, the ventral dermis is transformed into mammary mesenchyme and the entire ventral epidermis becomes nipple skin. These alterations in cell fate require that PTHrP be expressed during development and they require the presence of the PTH/PTHrP receptor. Finally, PTHrP signaling regulates the epidermal and mesenchymal expression of LEF1 and (β)-catenin, suggesting that these changes in cell fate involve an interaction between the PTHrP and Wnt signaling pathways.

Histo- and cytophysiology of the lactating mammary gland of the African elephant (Loxodonta africana)

The lactating mammary gland of the African elephant (Loxodonta africana) has been studied with a panel of morphological techniques focusing on (1) the functional changes during the secretory process, (2) proliferative process [by application of proliferating cell nuclear antigen (PCNA) immunohistochemistry] and apoptotic phenomena [by use of the TUNEL technique] in the individual lobules, and (3) components of milk and milk-fat-globule membrane. In the lactating gland, the lobules are variably differentiated; within a lobule, however, the alveoli are usually similarly differentiated. The morphology of their alveoli suggests a classification of the lobules into types 1-3. Lobules of type 1 are composed of immature tubular alveoli with mitotic figures and numerous PCNA-positive nuclei; advanced type 1 alveoli contain abundant glycogen and specific secretory granules. Lobules of type 2 are further subdivided. In type 2a lobules, the epithelial cells of the alveoli form tall apical protrusions, which in part are occupied by small lipid droplets and which are pinched off in an apocrine fashion. The number of lysosomes varies considerably. Type 2b is the most common type, with striking basal membrane foldings, abundant rough endoplasmic reticulum cisterns, large Golgi apparatus, numerous mitochondria, lipid droplets, and protein vesicles with 30- to 90-nm-wide casein micelles. The lipid droplets are pinched off with minimal amounts of cytoplasm. Type 2c is composed of alveoli with a cuboidal epithelium and few signs of secretory activity. Increasing expression of peanut-agglutinin-binding sites parallels the maturation and differentiation of the glandular cells. Type 3 lobules are marked by numerous TUNEL-positive nuclei and large lipid droplets and are apparently degenerating structures. Cytokeratin (CK) 14 is usually present in the myoepithelial cells; CK 19 and CK 7 mark ductal and immature alveolar epithelia. Milk protein content varies between 2.6% and 6.3%, and casein micelles range from 35 to 90 nm in diameter. The diameter of intra-alveolar milk fat globules ranges from 5 to 25 micrometer and the membranes bear a filamentous surface coat composed of membrane-anchored mucins; gel-electrophoretic analysis of these mucins from different individuals demonstrates the presence of mucin MUC 1, which is expressed with considerable genetic heterogeneity.

Identification of specific relaxin-binding cells in the human female

Relaxin is secreted during pregnancy, but it has no verified effects in humans. The objective of the present study was to identify the cells containing specific relaxin-binding sites in the uterine cervix, vagina, uterus, mammary glands, mammary nipples, and term placenta in the human. The uterine cervix, vagina, and uterus were obtained from hysterectomy specimens. Mammary glands and nipples were obtained after modified radical mastectomy. Placenta was obtained after normal delivery. Tissue samples were cut into slices (0.5-3 cm3), frozen in liquid nitrogen, and cryosectioned (8 microm). Cells that bind relaxin were identified by sequential application of biotinylated porcine relaxin probe, antibiotin immunoglobulin G conjugated to 1 nm colloidal gold, and silver enhancement for signal amplification. Relaxin bound with specificity to epithelial cells, smooth muscle cells, and blood vessels in the cervix, vagina, uterus, and mammary nipples; to epithelial cells and blood vessels in the mammary glands; and to skin of the mammary nipples. In addition, relaxin bound to individual cell types within the term placenta (amnion epithelium, syncytiotrophoblasts, blood vessels), and to sebaceous glands within the nipples. We conclude that the specific relaxin-binding cells probably contain relaxin receptors. Identification of putative relaxin receptors may provide insight into physiological and/or therapeutic roles of relaxin in the human.

Histological changes in mouse nipple tissue during the reproductive cycle

To obtain detailed information about the histological changes occurring in the mouse nipple during the reproductive cycle, we examined and quantified the S-phase of cell by immunohistochemical staining with bromodeoxyuridine (BrdU), and analysed histologically the subepithelial fibrous elements. The nipple markedly increased in size dramatically on days 15-18 of pregnancy. The densities of cells in the epidermis and dermis were very high during the early stages of pregnancy but low during lactation. In the epithelium of the lactiferous sinus, the densities of cells did not differ significantly among stages. The BrdU antibody labeling revealed a number of BrdU-positive cells in the basal layer of the epidermis and epithelium of the lactiferous sinus. The ratios of BrdU-positive cells to total cells in the epidermis and the epithelium of the lactiferous sinus were highest on day 15 and day 10 of pregnancy, respectively. After lactation, however, the ratios were similar to those in the virgin stage. No significant differences were detected in the dermis among all stages. The number of collagen and elastic fibers increased during lactation. These results indicate that cells in the epidermis and lactiferous sinus proliferated actively from day 10 to day 15 of pregnancy. The observation that cellular proliferation in the epithelial system of the nipple was stimulated at the early stage of pregnancy, while the dermis has two growth phases, with cellular proliferation during pregnancy and an increase in extracellular matrix during lactation, suggests that these two phenomena might be regulated by different factors.

Identification of specific relaxin-binding cells in the cervix, mammary glands, nipples, small intestine, and skin of pregnant pigs

We previously demonstrated that relaxin promotes growth and softening of the cervix and development of the mammary glands in the pregnant pig. An important aspect of understanding relaxin's mechanism of action in these tissues is to identify the specific cell type(s) that contains relaxin receptors, that is, to identify those cells that initiate relaxin's effects. The objective of the present study was to identify relaxin-binding cells in tissues known to respond to relaxin (cervix and mammary gland) as well as in tissues suspected of being responsive to relaxin (nipple, small intestine, and skin) in the pregnant pig. To accomplish that objective we developed an in vitro modification of an immunohistochemical technique recently developed for identification of relaxin-binding cells. Two groups of pregnant gilts were used: intact control (group C) and ovariectomized progesterone-treated (group OP). Group OP was ovariectomized on Day 40 of gestation (Day 40) and treated with progesterone (50 mg/2 ml corn oil i.m., twice daily) until Day 110 to maintain pregnancy. On Day 110, tissues from both groups were removed, cut into cubes (2-3 cm3), frozen in liquid nitrogen, and cryosectioned (8 microns). Specific cell types that bind relaxin were identified by sequential application of a biotinylated relaxin probe, antibiotin immunoglobulin G conjugated to 1 nm colloidal gold, and silver for signal amplification. The study demonstrates for the first time that relaxin binds with specificity to 1) blood vessels (cervix, mammary glands, nipples, small intestine); 2) smooth muscles in small intestine (circular, longitudinal, muscularis mucosa); and 3) skin from sites other than the mammary nipples (back, ear, thigh, leg). In addition, consistent with previous findings in the rat, prominent labeling was observed in epithelial cells in the cervix, mammary glands, and nipples; in smooth muscle cells in the cervix and mammary nipples; and in the skin of the nipples. There were no apparent differences in relaxin binding between group C and group OP. We conclude that the specific relaxin-binding cells in the cervix, mammary glands, nipples, small intestine, and skin of the pregnant pig probably contain relaxin receptors and, therefore, mediate relaxin's effects in these tissues.

Immunohistochemical localization of specific relaxin-binding cells in the cervix, mammary glands, and nipples of pregnant rats

Previously, we demonstrated that endogenous circulating relaxin promotes the growth and softening of the cervix, the development of the mammary glands, and the growth and development of nipples. Due to the remarkably similar modifications in the histological appearance of the extracellular matrix in the cervix, mammary glands, and nipples, we hypothesized that there may be a common mechanism(s) of action of relaxin in these tissues. A fundamental step toward understanding this mechanism is to identify specific cells that contain relaxin receptors, that is to identify those cells that initiate relaxin's effects within relaxin target tissues. To identify specific relaxin-binding cells in the cervix, mammary glands, and nipples of the pregnant rat, a biologically active biotinylated relaxin probe was prepared. This probe for putative relaxin receptors was administered to intact rats on day 18 of pregnancy. After 1 h, the animals were killed, and tissues were fixed by immersion in 4% paraformaldehyde for 10 h. Fixed tissues were rinsed in 0.1 M phosphate buffer (pH 7.4) and cryoprotected in an ascending series of 5%, 10%, and 20% sucrose solutions. The tissues were frozen in Tissue-Tek O.C.T. compound and stored at -70 C until sectioning. Frozen sections (12 microns) were cut on a Tissue Tek II cryostat at -24 C and thaw mounted on slides coated with 0.01% poly-l-lysine (mol wt, 300-6000). The biotinylated relaxin was localized in cryosections with an antibiotin immunoglobulin G conjugated to colloidal gold, which was subsequently visualized for light microscopy with silver intensification. Specific binding of the biotinylated relaxin was localized in the epithelial and smooth muscle cells of the cervix, the epithelial cells of the mammary glands, and the epithelial cells, smooth muscle cells, and skin of the nipples. We conclude that those cells exhibiting specific relaxin binding probably contain relaxin receptors and, therefore, mediate relaxin's effects in these tissues. As relaxin bound specifically to epithelial cells in the cervix, mammary glands, and nipples, we postulate that the epithelial cells may initiate a common mechanism of action that brings about modifications of the extracellular matrix in all three tissues.

Cutaneous hamartoma with pagetoid cells

We report an unusual cutaneous hamartoma with pagetoid cells characterized by the presence of intraepidermal cells resembling Toker's cells of the nipple. These cells were EMA positive and could be related to the histogenesis of some Paget's disease.

The epithelial cells and cell fragments in human milk

The cell fragments and epithelial cells in human milk were examined in samples obtained from 30 women: 3 of these provided sequential samples at weekly intervals for 110 days. Membrane-bound cytoplasmic fragments in the sedimentation pellet greatly outnumbered the population of intact cells in all samples. Most of the fragments were derived from secretory cells and contained numerous cisternae of rough endoplasmic reticulum, lipid droplets and Golgi vesicles containing casein micelles. Secretory epithelial cells were present in small numbers in all samples and after the 2nd month of lactation replaced the macrophage as the predominant cell type. Ductal epithelial cells represented less than 1% of the total cell population up to 8 days post-partum, but thereafter they were very rarely found. They occurred in aggregates of 2--4 cells and possessed tight junctions that circumscribed the area of cell-cell contact. All samples of milk contained squamous epithelial cells derived from the galactophores and/or the skin of the nipple. Bacteria were often attached to the surface of the squamous cells. The possible relationship between the presence of secretory epithelial cells in milk and the occurrence of milk proteins in the blood of lactating women is discussed.

Centrifugal cytology of nipple aspirate cells

Two improvements in the methodology for obtaining and preparing nipple aspirates from nonlactating women are reported. The first is the development and use of a new breast pump with a controllable vacuum and cups of various sizes. The second is the use of centrifugal cytology to prepare the dispersions. Twenty-one of 24 breasts of patients in the age range 30 to 49 years produced cellular dispersions which contained foam cells; of them, 13 contained ductal cells. A comparison of glutaraldehyde and ethanol fixation indicated that the cells appeared substantially the same.