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Breast gross cystic fluids. II. Electron microscopic analysis
326
The Breast
Breast gross cystic fluids. II. Electron microscopic analysis
Istituto Nazionale Tumori and Centro Medicina Nucleare CNR, Universita ‘Federic II’, Napoli, Italy
M Malatesta, F Mannello, A Cardinali, F Marcheggiani, M Sebastiani, S Amati, G Gazzanelli 1st. di Istologia e Analisi Lab., Universitit, Urbino, Italy; Centro di Senologia, AWL 2, Pesaro; 1st. di Anatomia e Istologia, Universitiz, Ancona, Italy
The multidrug resistant phenotype is characterized by the reduced intracellular retention of a number of structurally and functionally unrelated cytotoxic compounds due to the energy-dependent pump activity of P-glycoprotein (Pgp). Since 99”Tc-Sestamibi is a suitable transport substrate of Pgp, we tested whether the time-dependent fractional retention of this tracer could be used as an index of Pgp expression in untreated breast carcinomas. Twenty-seven patients with histologically confiied breast carcinoma were i.v. injected with 740 MBq (20 mCi) of 99”Tc-Sestamibi and static planar images of the breast were obtained at lo,60 and 240 minutes. The fractional retention of gh”Tc-Sestamibi was then calculated as the ratio between 60 and 10 minutes (R60/10) and between 240 and 10 minutes (R240/10) of decay corrected counts/pixel registered in the region of interest drawn around the tumor. Surgically excised tumors were then obtained from each patient and Pgp levels were determined using ‘ZSI-labeled MRK16 monoclonal antibody and in vitro quantitative autoradiography. The fractional retention of 99”Tc-Sestamibi at 60 and 240 minutes was significantly higher in tumors with low Pgp levels (group I, n = 18) as compared to that measured in tumors with high Pgp expression (group II, n = 9) (p < 0.001). In particular, R60/10 was 0.86 and 0.59 in breast carcinomas of group I and II, respectively, whereas the values of R240110 were 0.56 and 0.25 in low and high Pgp-expressing tumors, respectively. In conclusion, the determination of fractional retention of 99mTc-Sestamibimay be used as a simple functional test for Pgp expression in untreated breast cancer. A preliminary estimate of the sensitivity and the specificity of the test indicates its potential use in clinical practice to identify patients with a high probability of developing multidrug resistance.
Gross cystic breast disease (GCBD) is a benign condition which is reported to affect about 7% of women with highest incidence in the premenopausal decade. Although gross breast cysts are not premalignant lesions, several studies indicate that women with GCBD have an increased risk of subsequent cancer, particularly if the cysts are lined by apocrine epithelium and characterized by a fluid with low Na/K ratio. The aim of this work was to morphologically assessthe cellular composition of breast cyst fluids (BCF). After aspiration, BCF were fixed in phosphate-buffered aldchyde solution. The cell pellet was washed, post-fixed in osmium and then embedded in Epon. Ultrathin sections were stained with lead citrate and observed in a Zeiss 902 electron microscope. In Type I apocrine cyst fluids (characterised by Na/K < 3, high steroid hormones content and low protein concentration) the cells exhibited a roundish shape with a remarkable array of long cytoplasmic protrusions. The nuclei - one per cell and in eccentrical position - appeared very irregularly-shaped and contained fine homogeneous Ebrillar material. In the cytoplasm, the uniformly distributed endoplasmic reticulum (ER) was constituted by flattened cistemac of various lengths. Many ribosomes were found attached to the ER cisternae as well as scattered throughout the cytoplasmic matrix. The Golgi complexes - several per cell and in perinuclear position - were well developed. Several elongated mitochondria of a small size were randomly distributed. A large number of smooth, round vesicles occurred dispersed in the cytoplasm as well as associated to form membrane-bounded clusters (multivesicular bodies?). The isolated vesicles always showed weak electron-dense content, while various degrees of electron-density were presented by clustered vesicles. Some residual bodies were also found. Many membrane-bounded granules containing homogeneous, moderatelyelectron-dense material occurred in the cytoplasm, preferentially distributed in the peripheral regions of the cell and in the course of exocytosis. In Type II cyst fluids (characterized by Na/K ratio > 3, low steroids and high protein concentration) the cells were irregularly shaped, sometimes showing few and short cytoplasmic processes. The nuclei, one per cell and placed in an eccentrical position, showed a round shape and a homogeneously ftbrillar content. In the cytoplasm, a few ovoidal mitochondria and small cistemae of ER were occassionally observed, while high amounts of small, smooth, round vesicles were uniformly distributed. These vesicles occurred isolated and frequently surrounded by a membrane. Many of these vesicles contained strong electron-dense homogeneous material. Larger membrane bounded granules were frequently found in the peripheral position in the cell, sometimes in the course of exocytosis. Our study suggests that the two categories of breast cysts may correspond to different functional stages of the epithelium lining the cysts: Type I apocrine cysts could be the first functional stage of the cyst, subjected to enlargement owing to protease activities and to hormonal/growth factors stimuli. On the other hand, Type II flattened cysts might represent the late stage of development, with mechanisms leading to serum reabsorption of biochemical constituents.
Fractional retention of 99”Tc-sestamibifor the phenotypic assessmentof multidrug resistance in untreated breast cancer patients R Thomas, A Ciarmiello, S Del Vecchio, G Botti, G Cortino, G D’Aiuto, M Salvatore
DETECTION AND FOLLOW-UP New perspectives on breast cancer screening R Wilson City Hospital, Nottingham, UK Recent data acquired in Europe through various screening programmes have allowed us to identify some important issues about that the efficacy of breast cancer screening. Data from Malmo and Goteberg in Sweden, combined with the results of the metanalysis of all the random&d screening trials suggest that a significant reduction in mortality benefit may be achievable in women between the ages of 40 and 49. This benefit is significantly delayed when compared to older women and may be linked to the higher proportional detection of ductal carcinoma in situ in younger women. In the UK both randomised trials and observational studies have demonstrated the efficacy of two view mammography in considerably improving the small cancer detection and specificity of screening. On the technical side it has been clearly demonstrated that small cancer detection is improved when the mean optical density of screening mammograms is maintained at 1.6 (range 1.4 to 1.8 - Wallis et al, 1995). In the UK, the breast screening frequency trial was recently completed and the results of the analysis of one year versus three yearly screening are anticipated towards the end of 1997. Analyses of both interval cancers and incident round detected breast cancers have identified a number of radiological features that are deserving of particular attention. Small ill-defined mass lesions without distortion and local&d areas of architectural distortion are particularly common features on retrospective review. Radiologists need to pay particular attention to abnormalities occurring in the so called “review areas”.
The Breast
Breast gross cystic fluids. II. Electron microscopic analysis
Istituto Nazionale Tumori and Centro Medicina Nucleare CNR, Universita ‘Federic II’, Napoli, Italy
M Malatesta, F Mannello, A Cardinali, F Marcheggiani, M Sebastiani, S Amati, G Gazzanelli 1st. di Istologia e Analisi Lab., Universitit, Urbino, Italy; Centro di Senologia, AWL 2, Pesaro; 1st. di Anatomia e Istologia, Universitiz, Ancona, Italy
The multidrug resistant phenotype is characterized by the reduced intracellular retention of a number of structurally and functionally unrelated cytotoxic compounds due to the energy-dependent pump activity of P-glycoprotein (Pgp). Since 99”Tc-Sestamibi is a suitable transport substrate of Pgp, we tested whether the time-dependent fractional retention of this tracer could be used as an index of Pgp expression in untreated breast carcinomas. Twenty-seven patients with histologically confiied breast carcinoma were i.v. injected with 740 MBq (20 mCi) of 99”Tc-Sestamibi and static planar images of the breast were obtained at lo,60 and 240 minutes. The fractional retention of gh”Tc-Sestamibi was then calculated as the ratio between 60 and 10 minutes (R60/10) and between 240 and 10 minutes (R240/10) of decay corrected counts/pixel registered in the region of interest drawn around the tumor. Surgically excised tumors were then obtained from each patient and Pgp levels were determined using ‘ZSI-labeled MRK16 monoclonal antibody and in vitro quantitative autoradiography. The fractional retention of 99”Tc-Sestamibi at 60 and 240 minutes was significantly higher in tumors with low Pgp levels (group I, n = 18) as compared to that measured in tumors with high Pgp expression (group II, n = 9) (p < 0.001). In particular, R60/10 was 0.86 and 0.59 in breast carcinomas of group I and II, respectively, whereas the values of R240110 were 0.56 and 0.25 in low and high Pgp-expressing tumors, respectively. In conclusion, the determination of fractional retention of 99mTc-Sestamibimay be used as a simple functional test for Pgp expression in untreated breast cancer. A preliminary estimate of the sensitivity and the specificity of the test indicates its potential use in clinical practice to identify patients with a high probability of developing multidrug resistance.
Gross cystic breast disease (GCBD) is a benign condition which is reported to affect about 7% of women with highest incidence in the premenopausal decade. Although gross breast cysts are not premalignant lesions, several studies indicate that women with GCBD have an increased risk of subsequent cancer, particularly if the cysts are lined by apocrine epithelium and characterized by a fluid with low Na/K ratio. The aim of this work was to morphologically assessthe cellular composition of breast cyst fluids (BCF). After aspiration, BCF were fixed in phosphate-buffered aldchyde solution. The cell pellet was washed, post-fixed in osmium and then embedded in Epon. Ultrathin sections were stained with lead citrate and observed in a Zeiss 902 electron microscope. In Type I apocrine cyst fluids (characterised by Na/K < 3, high steroid hormones content and low protein concentration) the cells exhibited a roundish shape with a remarkable array of long cytoplasmic protrusions. The nuclei - one per cell and in eccentrical position - appeared very irregularly-shaped and contained fine homogeneous Ebrillar material. In the cytoplasm, the uniformly distributed endoplasmic reticulum (ER) was constituted by flattened cistemac of various lengths. Many ribosomes were found attached to the ER cisternae as well as scattered throughout the cytoplasmic matrix. The Golgi complexes - several per cell and in perinuclear position - were well developed. Several elongated mitochondria of a small size were randomly distributed. A large number of smooth, round vesicles occurred dispersed in the cytoplasm as well as associated to form membrane-bounded clusters (multivesicular bodies?). The isolated vesicles always showed weak electron-dense content, while various degrees of electron-density were presented by clustered vesicles. Some residual bodies were also found. Many membrane-bounded granules containing homogeneous, moderatelyelectron-dense material occurred in the cytoplasm, preferentially distributed in the peripheral regions of the cell and in the course of exocytosis. In Type II cyst fluids (characterized by Na/K ratio > 3, low steroids and high protein concentration) the cells were irregularly shaped, sometimes showing few and short cytoplasmic processes. The nuclei, one per cell and placed in an eccentrical position, showed a round shape and a homogeneously ftbrillar content. In the cytoplasm, a few ovoidal mitochondria and small cistemae of ER were occassionally observed, while high amounts of small, smooth, round vesicles were uniformly distributed. These vesicles occurred isolated and frequently surrounded by a membrane. Many of these vesicles contained strong electron-dense homogeneous material. Larger membrane bounded granules were frequently found in the peripheral position in the cell, sometimes in the course of exocytosis. Our study suggests that the two categories of breast cysts may correspond to different functional stages of the epithelium lining the cysts: Type I apocrine cysts could be the first functional stage of the cyst, subjected to enlargement owing to protease activities and to hormonal/growth factors stimuli. On the other hand, Type II flattened cysts might represent the late stage of development, with mechanisms leading to serum reabsorption of biochemical constituents.
Fractional retention of 99”Tc-sestamibifor the phenotypic assessmentof multidrug resistance in untreated breast cancer patients R Thomas, A Ciarmiello, S Del Vecchio, G Botti, G Cortino, G D’Aiuto, M Salvatore
DETECTION AND FOLLOW-UP New perspectives on breast cancer screening R Wilson City Hospital, Nottingham, UK Recent data acquired in Europe through various screening programmes have allowed us to identify some important issues about that the efficacy of breast cancer screening. Data from Malmo and Goteberg in Sweden, combined with the results of the metanalysis of all the random&d screening trials suggest that a significant reduction in mortality benefit may be achievable in women between the ages of 40 and 49. This benefit is significantly delayed when compared to older women and may be linked to the higher proportional detection of ductal carcinoma in situ in younger women. In the UK both randomised trials and observational studies have demonstrated the efficacy of two view mammography in considerably improving the small cancer detection and specificity of screening. On the technical side it has been clearly demonstrated that small cancer detection is improved when the mean optical density of screening mammograms is maintained at 1.6 (range 1.4 to 1.8 - Wallis et al, 1995). In the UK, the breast screening frequency trial was recently completed and the results of the analysis of one year versus three yearly screening are anticipated towards the end of 1997. Analyses of both interval cancers and incident round detected breast cancers have identified a number of radiological features that are deserving of particular attention. Small ill-defined mass lesions without distortion and local&d areas of architectural distortion are particularly common features on retrospective review. Radiologists need to pay particular attention to abnormalities occurring in the so called “review areas”.