Benign Smooth Muscle Cell Metaplasia in Breast

Three different benign breast lesions showing smooth muscle cells in the stroma are reported. Benign smooth muscle cells are rarely found in the breast, and it is likely that they originate from metaplastic changes of the stroma itself.

Contrast-enhanced sonography in the examination of benign and malignant adnexal masses

Our objective was to characterize the properties of an intravascular ultrasonographic contrast agent in examination of adnexal masses and to compare contrast agent properties between benign and malignant adnexal tumors. Fifty-eight consecutively examined women with suspected ovarian tumors were examined preoperatively by power Doppler ultrasonography, first without and then with contrast agent enhancement (Levovist). Fourteen women had ovarian cancer, 3 had borderline ovarian tumors, 18 had benign ovarian neoplasms, and 23 had functional adnexal cystic masses or endometriomas. The effect of the contrast agent was evaluated visually and by using computerized power Doppler signal intensity measurements. In visual evaluation, the brightness of the power Doppler signal and the amount of recognizable vascular areas increased in each tumor after contrast agent administration. The number of vessels in power Doppler ultrasonograms, both before and after contrast agent enhancement, was significantly higher in malignant than in benign adnexal masses, as also was the increase in the number of recognizable vessels after contrast agent administration. Contrast agent uptake time was significantly shorter in malignant than in benign tumors. No significant differences were found in the power Doppler signal intensities or their changes between benign and malignant tumors. In conclusion, use of sonographic contrast agent facilitates imaging of tumor vessels. For differentiation of benign and malignant tumors, the kinetic properties of the contrast agent, such as uptake and washout times, may have more potential than the use of the contrast agent in anatomic imaging of the tumor vessels.

Eccrine syringofibroadenoma (Mascaro): an ultrastructural study

To confirm the eccrine acrosyringeal differentiation of eccrine syringofibroadenoma (ESFA) and to elucidate the histogenesis of its angiofibrotic stroma, a case of ESFA from a 45-year-old man was examined by light and electron microscopy. Histologically, the parenchyma featured anastomosing, slender epithelial cords containing small cuboidal cells and occasional duct-like structures. The stroma had increased numbers of mast cells, increased capillaries with swollen endothelial cells, and prominent fibrosis. Ultrastructurally, the following findings were characteristic of ESFA: a) abundant glycogen particles in epithelial cells, b) numerous intracytoplasmic and extracellular spaces lined with microvilli, c) intraepithelial duct formation, consisting of microvilli, vesicles, rod-shaped dense bodies, multivesicular dense bodies, and peripheral network of tonofilaments, and d) large numbers of mast cells, closely associated with fibroblasts, surrounding increased numbers of capillaries containing swollen endothelial cells. These ultrastructural features support the acrosyringeal differentiation of ESFA. We hypothesize that mast cell hyperplasia and degranulation may play an important role in the formation of the angiofibrotic stroma.

Eccrine syringofibroadenomatosis: a clinical and histologic study and review of the literature

A 56-year-old man had an 11-year history of a psoriasiform eruption of the palms, soles, and shins. An examination revealed well-demarcated patches and plaques of erythematous, fissured, and hyperkeratotic skin with focal erosions. There was no clinical evidence of ectodermal dysplasia. On histologic examination these lesions proved to be eccrine hamartomas that consisted of anastomosing cords and strands of cuboidal epithelial cells with well-formed ducts and a fibrovascular mucinous stroma. Eccrine ductal origin was indicated by histopathologic, histochemical, immunopathologic, and electron microscopic evaluation. These multiple palmoplantar eccrine hamartomas, unassociated with ectodermal dysplasia, represent a sporadic hamartomatous condition that is best designated as "eccrine syringofibroadenomatosis."

Changes in the extracellular matrix of the normal human breast during the menstrual cycle

The normal human mammary gland undergoes a well defined sequence of histological changes in both epithelial and stromal compartments during the menstrual cycle. Studies in vitro have suggested that the extracellular matrix surrounding the individual cells plays a central role in modulating a wide variety of cellular events, including proliferation, differentiation and gene expression. We therefore investigated the distribution of a number of extracellular matrix molecules in the normal breast during the menstrual cycle. By use of indirect immunofluorescence, with specific antibodies, we demonstrated that laminin, heparan sulphate proteoglycan, type IV collagen, type V collagen, chondroitin sulphate and fibronectin undergo changes in distribution during the menstrual cycle, whereas collagen types I, III, VI and VII remain unchanged. These changes were most marked in the basement membrane, sub-basement membrane zone and delimiting layer of fibroblasts surrounding the ductules where basement membrane markers such as laminin, heparan sulphate proteoglycan, and type IV and V collagens appear greatly reduced during the mid-cycle period (days 8 to 22). These results suggest that some extracellular matrix molecules may act as mediators in the hormonal control of the mammary gland, whereas others may have a predominantly structural role.

Occurrence of epidermal growth factor receptors in benign and malignant ovarian tumors and normal ovarian tissues: an immunohistochemical study

Epidermal growth factor receptor (EGF-R) was studied with monoclonal antibody 2E9 on 50 ovarian tumors of various histological types and 10 non-tumorous ovarian tissues by immunohistochemistry. Enhanced expression was observed in 26/50 (52%) of the tumors. Only 25 out of 46 epithelial tumors (54%) showed positivity in epithelial tumor cells. Staining was cytoplasmic in all cases. No correlation was established between EGF-R expression and the histological type of the epithelial tumor. Apart from EGF-R expression in tumor cells, low immunoreactivity was also observed in stromal and endothelial cells in both normal and tumorous ovarian tissues. Furthermore in 8/9 specimens containing necrotic areas, EGF-R was noticed in these areas as well. Both of the latter observations may have impact on the evaluation of the prognostic value of EGF-R activity in tumors, when based on EGF-R measurements using biochemical binding studies. We therefore recommend that EGF-R is measured with both methods in studies regarding its clinical value.

Frequency of cytologic features in fine needle aspirates from histologically and cytologically diagnosed fibroadenomas

Identification of key cytologic criteria for various lesions by means of stepwise logistic regression is common today and is often claimed to facilitate cytologic diagnosis. As can be expected, there usually is good agreement between the selected criteria and those given in the cytologic literature. In a study by Bottles et al based on 64 fibroadenomas, stroma, antler horn clusters and honeycomb sheets differentiated fibroadenoma from ductal carcinoma. We applied Bottles's criteria to our fibroadenoma material in order to test their value in clinical cytologic practice. In fine needle aspirates from histologically (cytologically) diagnosed fibroadenomas, stroma was found in 41 (57%), antler horn clusters in 59 (90%) and honeycomb sheets in 62 (81%), which reduced the clinical value of the criteria.

Expression of heat shock protein 70 and c-myc protein in human breast cancer: an immunohistochemical study

The major heat shock protein, HSP70, protects cells from a variety of stressful stimuli, while c-myc protein allegedly stimulates the expression of HSP70 by transacting on the HSP70 promotor. The present study was aimed at correlating the expression of HSP70 with that of c-myc protein in benign and malignant breast lesions. Indirect immunoperoxidase and immunoblotting techniques using monoclonal antibodies were employed. Fresh frozen sections were prepared from five fibroadenomas and 59 breast carcinomas. Immunohistochemically, both substances were localized in the nuclei and/or cytoplasm of normal and neoplastic epithelial cells. The stromal cells were positive for c-myc protein but negative for HSP70. The expressions of HSP70 and c-myc protein were comparable to each other in the malignant cells from 37 (63%) carcinomas. In 17 (29%) carcinomas, c-myc protein expression predominated over that of HSP70, whereas in five (8%) carcinomas, HSP70 was predominant. Carcinomas with high-grade nuclear atypia often showed negative HSP70 staining, whereas tumors with nuclear HSP70 localization tended to accompany lower-grade nuclear atypia. A similar relation was also observed between c-myc protein expression and nuclear atypia of the tumor. All five fibroadenomas and most of the non-neoplastic epithelial cells adjacent to cancer showed strong reactivities with both substances. Immunoblot analysis for HSP70 revealed a clear, single band in the extract of tumors with strong HSP70 staining, but no, or only faint, bands were seen in the extract of immunohistochemically HSP70-negative carcinomas. The discrepancy between the expressions of each substance in a certain percentage of breast carcinomas may suggest the presence of HSP70 production mechanisms other than the c-myc protein-triggered promotor pathway.

Glial fibrillary acidic protein immunoreactivity in normal and diseased human breast

Immunostaining for glial fibrillary acidic protein (GFAP) identifies a minor subpopulation of immunoreactive myoepithelial cells in the normal resting human breast. The GFAP-immunoreactive cells also express a panel of myoepithelial cell markers, including cytokeratin 14 (CK 14), vimentin, smooth-muscle-specific actin isoforms, nerve growth factor receptor (NGFR) and common acute lymphoblastic leukaemia antigen (CALLA). The percentage of GFAP-immunoreactive myoepithelial cells is greatly increased in various neoplastic and non-neoplastic diseases of the breast, being highest in adenomyoepitheliomas. Furthermore, in all the instances of fibroadenoma, phyllodes tumour, epitheliosis and gynaecomastia, a variable number of epithelial cells also acquires immunoreactivity for GFAP, vimentin, CK 14, NGFR and, to a lesser extent, for CALLA. Conversely, GFAP immunoreactivity has never been encountered in the malignant cells of the different types of breast carcinoma. These findings suggest that the expression of GFAP might be a (possibly transient) feature of proliferating epithelial and myoepithelial cells in breast diseases other than carcinomas.

[Intracytoplasmic lumina of benign and malignant breast diseases--a light and electron microscopic study]

Intracytoplasmic lumina (ICLs) of 70 cases with breast carcinoma and 29 cases with benign breast diseases were observed by light and electron microscopy. ICLs were morphologically divided into two types. Type A was characterized by the presence of secretory materials stained with eosin in the lumen and Type B by the cytoplasmic vacuoles under light microscope. Electron microscopic observation on Type A ICLs showed numerous filiform microvilli projecting towards the lumen and various amounts of secretory materials in the lumen. Type B of ICLs only had scanty and short microvilli and rarely secretory materials in the lumen. The results indicated that: 1. The frequency of ICLs in breast cancer was significantly higher than that in benign breast disease (P less than 0.01). 2. The frequency of ICLs in breast cancer showed strong negative correlation with its histological grades but not with its histological types. 3. ICLs had similar frequency under both light and electron microscopes. As a relatively specific structure in breast carcinoma cells, ICLs may be helpful in the diagnosis of breast carcinoma and establishment of the breast origin for metastatic carcinoma.

Pleomorphic adenoma (benign mixed tumor) of the breast. An immunohistochemical, flow cytometric, and ultrastructural study and review of the literature

Pleomorphic adenoma (or benign mixed tumor) of the breast is a rare benign neoplasm that might be misinterpreted both clinically and pathologically as a malignant tumor. The authors present an additional case of this unusual lesion studied by immunohistochemistry, electron microscopy, and flow cytometry. A 77-year-old white woman presented with a 2-cm, nontender, mobile, calcified, right subareolar mass suggestive of a fibroadenoma. Microscopically, the tumor resembled a pleomorphic adenoma occurring in salivary glands. Positive immunostaining for S-100 protein, cytokeratin, and muscle-specific actin, as well as the ultrastructural presence of intermediate filaments with dense bodies and intercellular junctions, supported the predominant myoepithelial cell differentiation within the tumor, whereas the epithelial cell component stained only with cytokeratin and contained formed lumina with surface microvilli. The DNA pattern was diploid. The patient is alive and well 14 months after surgery. The authors' findings confirm that pleomorphic adenoma of the breast is a benign neoplasm in which myoepithelial cell proliferation plays a major role in tumorigenesis.

Ultrastructural analysis of fine needle aspirates from benign breast lesions

Thirty six fine needle aspirates from various types of benign breast lesions were examined by electron microscopy and correlated with their cytological appearances. In all cases the parenchyma consisted of clumps of cohesive cells with the ultrastructural features of epithelial cells. In many cases, particularly from fibroadenomas, the parenchyma consisted of single layers of polarised epithelial cells showing lumen formation. Similar arrays of apocrine epithelial cells were observed in 60% of fibrocystic lesions. The more solid clumps from hyperplastic lesions consisted of epithelial cells of variable shape and electron density with disorganised lumen formation. Irrespective of the type of lesion, the epithelial cells were not normally subtended by myoepithelial cells or basal lamina. The extraction process seems to result in a shearing between the epithelium and basal lamina with lysis of the myoepithelial cells. Most naked nuclei probably result from lysed myoepithelial cells.

Semiquantitative analyses of fine needle aspirates from benign and malignant breast lesions

A scoring system for the assessment of fine needle aspirates of benign and malignant breast lesions was devised which showed a positive correlation (r = 0.67) between the scores obtained from the fine needle aspirates from ductal carcinomas and the Bloom and Richardson-type scores for their paired excision biopsy specimens. This system permitted grades II and III ductal breast carcinoma to be distinguished reliably from grade I tumours but no correlation with the lymph node state of patients with breast carcinoma was shown. Some overlap between the scores for grade I ductal carcinomas and some benign lesions was found, and this underlines a need for caution in the reporting of such equivocal aspirates. No cytological features that distinguished reliably ductal from lobular carcinoma were identified but the same spectrum of severity of cytological abnormality in the ductal and lobular carcinoma aspirates was seen. This system may be of prognostic value in the assessment of lobular carcinoma which has hitherto defied histological grading.

The distribution of lectin receptor sites in human breast lesions

Conflicting data regarding the status of A, B, H and T antigens in epithelium of normal, mastopathies, fibroadenomas and carcinomas of the breast stimulated us to re-examine the carbohydrate residues in these condition. Currently, we extended the number of carbohydrate residues studied by using ten different biotinylated lectins as probes and avidin-biotin-peroxidase complex (ABC) as a visualant. In addition, the pattern of lectin staining of cancerous cells in primary and metastatic sites was compared. In primary and metastatic breast carcinomas, lectin receptor sites were stained more intensely with Concanavalia ensiformi agglutinin (*Con A), Ricinus communis agglutinin-I (RCA-I) and wheat germ agglutinin (WGA), than in normal breast, in mastopathies or in fibroadenomas. Cryptic receptor sites for peanut agglutinin (PNA) were stained in all cases of breast carcinomas, while free PNA sites stained only in a few cases of well-differentiated carcinomas. Receptors sites for Ulex europaeus agglutinin-I (UEA-I) stained non-malignant epithelium of patients with blood group H but did not stain malignant cells. The results show significant differences in lectin-binding patterns and staining intensities between normal and non-malignant, and malignant epithelial breast cells. Furthermore, these results indicate that in malignant cells, there is an increased content of sialic acid-rich carbohydrates but not of asialylated glycoconjugates.

Adenofibroma of the rete testis. A case report with electron microscopy findings

The light and electron microscopic characteristics of an adenofibroma of the rete testis in a 51-year-old man are described. The tumor was 5.5 cm in greatest diameter and situated in the anterior superior portion of the right testis. It was composed mainly of mesenchymal and secondary epithelial proliferation. Long slit-like spaces and short tubules lined by a layer of epithelial cells were seen in the mesenchymal tissue. The epithelium was histochemically and ultrastructurally similar to that of the rete testis, and the tumor was considered to be of rete testis origin.

Cytologic characteristics and origin of naked nuclei in breast aspirate smears

To elucidate the origin of "naked nuclei" in breast aspiration smears, 17 cases of fibroadenoma were studied by light and electron microscopy. The ATPase reaction was also studied at both levels. The aspirates contained two types of naked nuclei: denuded degenerated nuclei and oval to spindle-shaped nuclei with very scanty cytoplasm. The cytoplasm of the latter was rich in free ribosomes and rough-surfaced endoplasmic reticulum but was devoid of cytoplasmic filaments and dense bodies. These cells were negative for ATPase activity. Stromal cells, not myoepithelial cells, characteristically demonstrated such cellular features in the aspirates and tissue sections studied. We conclude that most naked nuclei are derived from stromal cells.

Stromal proliferations of the breast: an ultrastructural and immunohistochemical evaluation of cystosarcoma phyllodes, juvenile fibroadenoma, and fibroadenoma

The stromal cells of three cystosarcoma phyllodes, five typical fibroadenomas, and one juvenile fibroadenoma were studied by light and electron microscopy. Immunohistochemical staining for the S-100 protein also was performed on tissues from each of the three categories. On ultrastructural examination, cells comprising the three varieties of lesions were similar. Cells with fibroblastic features predominated in all cases. Myoid differentiation was present in two cases, one of cystosarcoma and one of fibroadenoma. Junctional complexes were present in the cystosarcomas but not in the fibroadenomas. Basal lamina was focally present around stromal cells in the cystosarcoma phyllodes but was not evident around cells of the typical fibroadenomas or the juvenile fibroadenoma. Stromal cells of the fibroadenomas and the cystosarcoma phyllodes did not stain for S-100 protein. The results support the hypothesis that the proliferating cells in all three tumor categories are similar and have features of fibroblasts. The lack of staining for S-100 protein would suggest an origin different from the myoepithelia. The latter conclusion, however, must be interpreted with a degree of reservation as we have shown that not all myoepithelial cells stain with certain monoclonal antibodies directed against the alpha and beta chain of S-100 protein.

Multicentric ovarian and extraovarian cystadenofibroma

A case of multicentric ovarian and diffuse pelvic cystadenofibroma is described. Despite multicentricity, the histologic findings are completely benign. Electron microscopy was performed and possible mesothelial origin is discussed.

Fibroadenoma of the female breast with multinucleated giant cells

A fibroadenoma in the female breast is described, which contained multiple multinucleated giant cells within the stroma. The investigation indicated the giant cells to be of epithelial nature, caused by epithelial degeneration secondary to myoepithelial swelling of unknown cause. Their presence and morphology could cause anxiety about malignancy, but this was found groundless.

Ultrastructure of cystosarcoma phyllodes and fibroadenoma. A comparative study

Electron microscopic studies were conducted on 11 cases of cystosarcoma phyllodes (6 benign, 3 malignant, 2 recurrent), 1 stromal sarcoma, and 15 cases of fibroadenomas. Particular emphasis was placed on examination of the epithelial-stromal junction. The epithelial cells were basically similar in all cases. The basal lamina of fibroadenomas tended to be reduplicated, whereas in cystosarcoma phyllodes the basal lamina was less reduplicated and even focally absent. A continuous layer of delimiting fibroblasts was not present in either type of tumor. Stromal cells were generally fibroblasts, with 2 of 15 being fibroadenomas and 2 of 11 cystosarcoma phyllodes showing myofibroblastic differentiation. The stromal sarcoma also showed smooth muscle differentiation. The authors conclude that the epithelial-stromal junction is abnormal in both fibroadenomas and cystosarcomas, but the abnormality is different in these two tumors. Increasing prominence of stromal cell junctions and of lysosomes also correlated with the diagnosis of cystosarcoma, particularly the malignant variant.

Cytology of argyrophilic carcinoma of the breast

Aspirations of breast lesions from 57 patients were studied by evaluating Grimelius-stained smears in order to determine the cytologic features of argyrophilic carcinoma and the reliability of argyrophilia as a characteristic of malignancy. The cytologic preparations were compared with histologic material. Sixteen benign lesions, 24 carcinomas correctly diagnosed by cytology and 5 carcinomas with technically inadequate smears were argyrophil negative. Five of 12 carcinomas with equivocal cytology were argyrophilic. There was perfect to case-to-case correlation between argyrophilia seen on histologic slides and on smears. The smears of the 5 argyrophilic carcinomas and 2 of the argyrophil-negative carcinomas with equivocal cytology shared features in common not seen in the other 50 smears: elongated cells with eccentric, round-to-oval nuclei and granular or opaque cytoplasm. These features can alert the pathologist to the possibility of malignancy in smears with equivocal cytology. A positive stain for argyrophilia will further increase the index of suspicion.

Scanning electron microscopy of the human breast and its disorders

This article reviews the surface topography of the normal breast and its disorders. The results of our study of 132 cases are presented and compared with the literature.

Phyllodes tumour and stromal sarcoma of the breast: an ultrastructural comparison

The ultrastructure of the stromal cells of three benign and one malignant phyllodes tumours and three stromal sarcomas has been studied and compared with the stromal cells of two fibroadenomas and four normal lobules. One stromal sarcoma was possibly of nerve sheath origin, but the other two showed features in common with the phyllodes tumours and the fibroadenomas. Prominent electron dense cytoplasmic bodies with distinctive morphological features are described and a correlation with the degree of malignancy is postulated.

An ultrastructural study on periductal elastosis in human breast tumors

An ultrastructural study on elastosis of human breast tumors was made with special attention to the periductal elastosis and the cell responsible for elastic fiber formation. The elastosis was found prominently in scirrhous type of duct carcinoma. In the area of mild periductal elastosis, the elastic fibers with many microfibrils and a tiny central elastin were seen around the periductal fibroblasts which were characterized by attenuated cytoplasms with aggregates of microfilaments and slightly developed rough endoplasmic reticulum. With the thickening of the periductal wall, such an area was replaced by abundant mature elastic fibers with peripheral microfibrils and a few intervening ordinary fibroblasts. Therefore, it was suggested that the periductal fibroblasts which transformed into ordinary fibroblasts during the development of elastosis were primarily concerned with the elastic fiber formation. In the interlobular tissue in which both fibroblasts and myofibroblasts were present, the elastic fibers were larger than those of the periductal area and had less microfibrils in their periphery. The relationship between microfibrils and elastin during the early elastosis, maturation process of the elastic fibers, and cell modulation of the fibroblasts in the breast elastosis were discussed.

Multiple bilateral breast adenomata in identical adolescent Negro twins

Identical adolescent Negro twins presented with multiple bilateral breast adenomata. There were three pure tubular adenomata, one mixed tubular and fibroadenoma, four glandular fibroadenomata and one typical intracanalicular fibroadenoma. Tubular adenomata are exceedingly rare and this report adds a further three to the literature. Furthermore, the close similarity of the glandular fibroadenomata and tubular adenomata, the occurrence of tubular and fibroadenomatous areas in the same tumour, and the simultaneous occurrence of both tumour types in the same genetic setting, point to a close relationship between these types of neoplasm. The simultaneous occurrence of breast adenomata in identical twins suggests, but does not prove, an important genetic contribution to the aetiology of these tumours. The twins were both virgins, and, therefore, it is clear that pregnancy is not a pre-requisite for the development of tubular adenomata, as has been suggested.

The distribution of keratin type intermediate filaments in human breast cancer. An immunohistological study

Antibodies to different intermediate filament proteins can be used to distinguish cells of epithelial, mesenchymal, muscle, glial and neuronal origin. Antibodies to prekeratin which characterize cells of epithelial origin, and antibodies to vimentin which recognize cells of mesenchymal origin have been used to study twenty cases of breast carcinoma (sixteen infiltrating ductal carcinomas and four infiltrating intraductal carcinomas), two cases of cystic breast disease, two fibroadenomas and one case of benign cystosarcoma phylloides. The prekeratin and vimentin were detected using specific antibodies to these proteins by immunofluorescence microscopy using alcohol fixed paraffin-embedded tissues. In eighteen out of the twenty carcinomas the tumor cells were strongly and specifically stained by antibodies to prekeratin. DIfferent tumors gave different patterns of prekeratin staining. In contrast, when the same specimens were tested with the vimentin antibody, the tumor cells were unstained, and instead only the usual strong staining to fibroblasts and blood vessels in the stroma was observed. In cystic breast disease, fibroadenomas, and benign cystosarcoma phylloides, cells of epithelial origin were strongly stained by the prekeratin but not by the vimentin antibody.

Argyrophilic cells in carcinoma of the female breast

Argyrophilic hormone storage granules were sought in the tissue specimens obtained from 52 benign breast lesions (13 normal breasts, 27 cases of fibrocystic disease, 9 fibroadenomas, 2 intraductal papillomas, and 3 cases of gynecomastia) and from 90 adenocarcinomas of the female breast. No argyrophilic cells were found in the normal breast tissue or in the benign lesions studied. In three of the carcinomas (3.3%) such granules were found in the tumor cells. Using electron microscopy, the argyrophilic granules were shown to be of moderate or high electron density with an average diameter of 165 to 170 nm. Ectopic hormone production was not observed clinically in any of these three patients. The absence of argyrophilic cells in normal and benign ductal and acinar epithelium, and their occasional presence in breast carcinomas favors the concept of the histogenesis of these cells through genomic derepression during the course of neoplastic transformation.

Unusual cystadenofibromas: endometrioid, mucinous, and clear cell types

Cystadenofibromas are benign ovarian neoplasms containing both epithelial and stromal components. The epithelial component is usually of simple serous type resembling fallopian tube epithelium. Occasionally, tumors with unusual epithelial pattenrs are encountered. In this study, 16 cystadenofibromas with unusual epithelium are described. Twelve are examples of an endometrioid type, 3 of a clear cell (mesonephroid) type, and 1 of a mucinous-type epithelium. The stromal component in all tumors is identical to that of ordinary cystadenofibromas. One of the patients with a tumor containing endometrioid epithelium developed recurrence in the vagina after surgical removal of the ovarian tumor. The rest of the clinical features of these tumors are similar to those of ordinary cystadenofibromas with the exception that the median age is 10--20 years greater in the unusual-epithelium group.

Intramitochondrial rod-like inclusions in human breast tumors

Ultrastructural screening of human breast tumor biopsies has revealed, in 43% of the carcinomas, and in 16% of the benign lesions examined. the presence of rod-like inclusions in mitochondria of epithelial cells. The inclusions are cylindrical in cross section, with a diameter of about 50 nm, and show regular striations in longitudinal sections. They are probably derived from cristae. Mitochondria with inclusions are usually enlarged and are found most frequently in epithelial cells of invasive tumors and near zones of tumor necrosis. Similar although not identical inclusions have been observed by other investigators in the liver of women with hydatidiform mole or choriocarcinoma, of pregnant women, and of women taking oral contraceptives. Identical inclusions have been found in mitochondria of HeLa cells treated with anti-HeLa serum. Although no clear-cut correlations were found between the finding of inclusions and parameters such as age of patients, nuclear grade or lymphocytic infiltration of the breast tumors, it is conceivable that the presence of mitochondrial inclusions reflects the effect of hormonal or of immunological factors.

Myoepithelial differentiation and basal lamina deposition in fibroadenoma and adenosis of the breast

Sixteen cases of breast fibroadenomas and 11 of adenosis were studied ultrastructurally; emphasis was placed on the patterns of myoepithelial differentiation and the number and appearance of the basal laminae. Ducts of both fibroadenomas and adenosis showed well differentiated, peripherally arranged myoepithelial elements with conspicuous cytoplasmic filaments and numerous hemidesmosomes; focal myoepithelial multilayering occurred. Myoepithelial cells exhibited complex, convoluted cytoplasmic processes extending into the stroma and resulting in the formation of pseudocysts containing stromal material. Basal lamina deposition was invariably found; basal lamina reduplication was extremely frequent. Basal lamina discontinuities with cytoplasmic processes extending directly into the stroma were seen in adenosis. Myoepithelial features and conspicuous basal lamina deposition indicate advanced differentiation and correlate well with the benign prognosis of these lesions. The focal basal lamina gaps in adenosis may be significant in the long-term evolution of this and similar dysplastic processes.

Spectral and metabolic characteristics of mitochondrial fractions from rotenone-induced tumours

Mitochondrial fractions isolated from tumours induced with the respiratory inhibitor rotenone lack respiratory control, oxidative phosphorylation, are partially or totally insensitive to cyanide and have a near-normal content of respiratory carriers. These characteristics are more similar to those of mitochondria from atrophic mammary gland than to those of mitochondria from spontaneous mammary adenomas. Thus, the characteristic structural and biochemical mitochondrial alteration of rotenone-induced tumours would represent a lack of mitochondrial differentiation as the tumour develops from the atrophic mammary gland. Slices of rotenone-induced tumours are insensitive to oligomycin and dinitrophenol, thus indicating that glycolysis would be their sole source of metabolic energy.

Elastosis and other stromal reactions in benign and malignant breast tissue: an ultrastructural study

The stroma and stromal reaction in normal breast, benign, and malignant breast tissue was studied by electron microscopy. Elastosis is the main stromal response in infiltrating duct and lobular carcinomas. Medullary carcinoma elicits no significant elastosis but intraductal carcinoma has significant local elastosis. Benign conditions such as fibroadenoma and sclerosing adenosis produced no significant elastosis. The high number of elastic fibers and the high microfibril:elastin ratio indicate that most of the elastic fibers are recently secreted, probably by fibroblasts and myofibroblasts. The factors stimulating the increased production of elastic fibers and the prognostic significance of elastosis remain unclear.