Medullary carcinoma of the breast: interobserver variability in histopathologic diagnosis

To assess the interobserver reproducibility for the diagnosis of medullary carcinoma of the breast (MC), 53 previously diagnosed MCs were independently assessed by six observers for growth pattern, nuclear grade (NG), inflammation, tumor margin, intraductal component, and glandular features. Tumors were reclassified as MC, atypical MC, or infiltrating ductal carcinoma according to the histopathologic criteria of Ridolfi et al. (Cancer 40:1365, 1977), Wargotz and Silverberg (Hum Pathol 19:1340, 1988), and Pedersen et al. (Br J Cancer 63:591, 1991). NG was the most reproducible parameter, and tumor margin was the least, with consensus agreement by four of six observers for 49 (92%) and 26 (49%) of cases, respectively. Utilizing the histopathologic criteria proposed by Ridolfi et al., Wargotz and Silverberg, and Pedersen et al., consensus diagnoses were achieved in 37 cases (70%), 46 cases (87%), and 51 cases (96%), respectively. A consensus diagnosis of MC in all three systems was unassociated with tumor size, axillary lymph node status or overall survival (median follow-up: 89 mo). The consensus (or better) reclassification of 44/53 (83%), 35/53 (66%), and 27/53 (51%) previously diagnosed MC as atypical MC or infiltrating ductal carcinoma by the criteria of Ridolfi et al., Wargotz and Silverberg, and Pedersen et al., respectively, suggests that MC was previously over-diagnosed. While the scheme of Pedersen et al. is the most reproducible, additional follow-up information is necessary to determine the biological significance of this classification system. To minimize these difficulties in practice, pathologists should carefully adhere to published criteria and indicate the classification system utilized.

Aggressive papillary tumor of middle ear/temporal bone and adnexal papillary cystadenoma. Manifestations of von Hippel-Lindau disease

The occurrence of an aggressive papillary middle ear/temporal bone tumor (APMET) and a benign adnexal papillary tumor of probable mesonephric origin (APMO) in a patient with von Hippel-Lindau disease (VHL) is reported. Histologically, both tumors were identical to papillary cystadenomas of the epididymis and broad ligament of probable mesonephric derivation. A comprehensive literature review showed that including the current case, seven of 46 (15%) documented cases of APMET and four of four (100%) cases of APMO arose in patients with VHL. Given an estimated minimum birth incidence of 1/36,000, a one-sample test of binomial proportion using the exact method establishes that the association of APMET and APMO with VHL is highly significant (p = 1.4 x 10(-24) and 1 x 10(-18), respectively). The data indicate that APMET and APMO may represent major visceral manifestations of VHL. Accordingly, in the presence of one of these tumors strong consideration should be given to the diagnosis of VHL, given either the presence of another major component of VHL or documentation of VHL in at least one consanguineous relative.

Angiomatoid carcinoma and 'angiosarcoma' of the thyroid gland. A spectrum of endothelial differentiation

The existence of angiosarcoma of the thyroid gland and its relation to angiomatoid carcinoma have been debated. The authors reviewed eight angiomatoid thyroid neoplasms. Controls consisted of six sarcomatoid thyroid carcinomas without angiomatoid features and an angiosarcoma metastatic to the thyroid gland. All eight angiomatoid neoplasms consisted of epithelioid cells with prominent eosinophilic cytoplasm lining vascularlike spaces. All eight expressed vimentin. Four tumors were predominantly angiosarcomalike neoplasms, based on staining for factor VIII-related antigen (three of four), CD31 (four of four), CD34 (one of four), and Ulex europaeus I lectin (four of four); they lacked epithelial markers other than cytokeratin (two of four). Four tumors were designated as angiomatoid carcinomas, based on staining for multiple epithelial markers: cytokeratin (four of four), epithelial membrane antigen (three of four), thyroglobulin (three of four). Three angiomatoid carcinomas also expressed or labeled with one or more vascular markers: CD34 (one of four), CD31 (two of four), Ulex europaeus I lectin (one of four), factor VIII-related antigen (one of four). The metastatic angiosarcoma to the thyroid gland labeled for factor VIII-related antigen, vimentin, CD31, and with Ulex europaeus I lectin. It did not express CD34. The six sarcomatoid carcinomas without angiomatoid features stained for cytokeratin (four of six), epithelial membrane antigen (one of six), and vimentin (six of six). None labeled for thyroglobulin, factor VIII-related antigen, CD31, CD34, or with Ulex europaeus I lectin. Angiomatoid carcinomas of the thyroid gland exhibit both epithelial and endothelial features. "Angiosarcoma" may represent the extreme in this spectrum of endothelial differentiation. All tumors behaved in a similar clinical fashion characterized by persistent local disease, widespread metastases and poor prognosis.

Immunohistochemical detection of neuroblastomatous foci in composite adrenal pheochromocytoma-neuroblastoma

To determine if immunohistochemistry might aid in the identification of neuroblastomatous foci in composite adrenal tumors, the authors analyzed two examples of composite adrenal pheochromocytoma-neuroblastoma, 18 pure pheochromocytomas, and six pure neuroblastomas using peanut agglutinin and a panel of antibodies directed against neuroendocrine and neural-associated antigens. Pure pheochromocytoma had the following immunopositivity: vimentin 14/18, chromogranin 18/18, synaptophysin 18/18, S100 protein 0/18 (tumor cells), neurofilament 14/18, J1 beta-tubulin (J1) 18/18, microtubule-associated protein-2 13/18, glial fibrillary acidic protein 13/18, and peanut agglutinin 17/18. Pure neuroblastoma reacted positively as follows: vimentin 0/6, chromogranin 5/6, synaptophysin 4/6, S100 protein 0/6 (tumor cells), neurofilament 5/6, J1 6/6, microtubule-associated protein-2 6/6, glial fibrillary acidic protein 1/6, and peanut agglutinin 6/6. Each component of both composite tumors reacted similarly to the pure neoplasms. Although the frequency of positive staining was similar for pheochromocytoma and neuroblastoma, the intensity and pattern differed for several antigens. Pheochromocytoma was diffusely positive for synaptophysin and chromogranin, whereas staining was focal and punctate in neuroblastoma. Microtubule-associated protein-2, J1, and neurofilament antibodies highlighted the fibrillar background of neuroblastoma, which pheochromocytoma lacked. Pheochromocytoma contained focal, ball-like immunoreactivity for glial fibrillary acidic protein and vimentin, which was absent in neuroblastoma. These immunohistochemical distinctions can assist the clinically important recognition of neuroblastomatous foci in composite adrenal pheochromocytoma-neuroblastoma.

Detection of Epstein-Barr viral RNA in sinonasal undifferentiated carcinoma from Western and Asian patients

Undifferentiated carcinoma of the nasopharynx has a well-known association with Epstein-Barr virus (EBV), but only an inconsistent relationship has been identified in undifferentiated carcinomas occurring at other sites. We investigated 22 formalin-fixed, paraffin-embedded cases of sinonasal undifferentiated carcinomas (SNUCs) occurring in Western and Asian patients. A highly sensitive in situ hybridization method was performed using an antisense oligonucleotide probe to the EBER1 gene of EBV. We identified EBV RNA in seven of 11 SNUCs from Asian patients, but in none of the Western SNUC patients (0/11). The EBER1 signal was present in all or virtually all of the tumor cell nuclei in the seven EBV-RNA-positive Asian SNUCs. The latent membrane protein-1 (LMP1) of EBV was not identified in any of the five positive cases tested. Our results suggest that genetic predisposition or environmental/geographical cofactors play an important role in determining the strength of the association of SNUC with EBV.

Expression of parathyroid hormone-related protein and its receptor in human umbilical cord: evidence for a paracrine system involving umbilical vessels

OBJECTIVE

Our purpose was to study the expression and localization of parathyroid hormone-related protein and expression of the parathyroid hormone/parathyroid hormone-related protein receptor in human umbilical cord.

STUDY DESIGN

The expression and localization of parathyroid hormone-related protein and expression of the parathyroid hormone/parathyroid hormone-related protein receptor were studied in isolated tissues from the human umbilical cord by Northern analysis, reverse-transcriptase polymerase chain reaction, Southern gel analysis, and immunolocalization procedures at the light and electron microscopic levels.

RESULTS

Parathyroid hormone-related protein was abundantly expressed in the umbilical cord. Immunohistochemical and immunocytochemical techniques confirmed hormone localization in the amnion epithelial layer and in vascular smooth muscle and endothelial cells in vessels from the umbilical cord and placental chorionic plate. Multiplex reverse-transcriptase polymerase chain reaction identified expression of receptor messenger ribonucleic acid in vessels of the umbilical cord; this finding was verified by means of Southern gel analysis of the products of the reverse-transcriptase polymerase chain reaction.

CONCLUSION

A parathyroid hormone-related protein paracrine system appears to exist in human umbilical cord. We suggest that it may be involved in the control of fetal placental circulation.

Porcine somatotropin decreases acetyl-CoA carboxylase gene expression in porcine adipose tissue

Crossbred barrows were treated daily with porcine somatotropin (pST; 4 mg/d) from 79 to 127 kg BW to determine whether pST regulates the activity and gene expression of adipose tissue acetyl-CoA carboxylase (ACC), the rate limiting enzyme in de novo fatty acid synthesis. Administration of pST reduced ACC enzyme activity, protein content, and mRNA abundance in adipose tissue by 40 to 50%. When comparisons were made among all pigs, ACC enzyme activity and mRNA abundance were closely associated (r2 = .94). In summary, our results indicate that pST decreases ACC enzyme activity and that this is associated with a significant reduction in ACC mRNA abundance. We speculate that decreased ACC enzyme activity results from a reduction in ACC protein and that this occurs because pST reduces the abundance of mRNA available for translation.

The effect of ractopamine on beta-adrenoceptor density and affinity in porcine adipose and skeletal muscle tissue

We have evaluated the effect of feeding ractopamine (Rac), a phenethanolamine lean enhancer being developed for commercial use in finishing pigs, on beta-adrenoceptor (beta-AR) number and ligand-receptor binding affinity in adipose and muscle tissues. Pigs weighing 78 +/- 1 kg were fed Rac (20 mg/kg of diet) for 0 (control), 1, 8, or 24 d before being killed at 105 +/- 1 kg BW. beta-adrenoceptor density (per milligram of protein) was decreased by Rac up to approximately 50% in both the middle and the outer layers of subcutaneous (SQ) adipose tissue. Orthogonal contrasts indicated significant (P < or = .05) linear effects of Rac in middle and outer SQ adipose tissue, and also a significant (P < or = .05) quadratic effect of Rac in the middle layer. Ractopamine did not affect the maximal binding (Bmax) of longissimus muscle. The relative affinity with which the beta-AR population of the tissues examined bound the radioligand ([3H]dihydroalprenolol) was not influenced by Rac. Likewise, feeding Rac had no effect on the affinity of the beta-AR for Rac. The data indicate that a Rac-induced reduction in the Bmax of adipose tissue may account for the diminished in vitro lipolytic potency of exogenous Rac after prolonged periods of Rac feeding, and that Rac-induced desensitization differs between adipose and skeletal muscle tissues.

Limitations of ractopamine to affect adipose tissue metabolism in swine

To determine the temporal effect of ractopamine (Rac), a phenethanolamine, on adipose lipogenic enzyme activity and gene expression, 20 crossbred barrows were fed Rac (20 mg/kg of diet) for 0, 1, 8, or 24 d before slaughter (105 +/- 1 kg). Ractopamine had no effect (P > .05) on the activity of acetyl-coenzyme A carboxylase or malic enzyme in either the middle or outer layers of subcutaneous adipose tissue. Similarly, mRNA abundance for acetyl-coenzyme A carboxylase and the glucose transport proteins Glut 1 and Glut 4 were not affected by Rac in either adipose depot. Despite the inability of Rac to affect adipose tissue metabolism, Rac increased nitrogen retention, longissimus muscle area, and alpha-actin gene expression in skeletal muscle. Results indicate that Rac was not a functional beta-adrenergic agonist toward adipose tissue in this study. We suggest that the response to Rac in adipose tissue is masked by a combination of factors including tissue insensitivity, Rac-dose limitation, inherent partial agonism of Rac, and beta-adrenoceptor down-regulation.

Medullary carcinoma of the breast. Identification of lymphocyte subpopulations and their significance

Fifty-two infiltrating breast carcinomas with medullary features (BCMF) were studied immunohistochemically to determine the immunophenotype of the mononuclear tumor inflammatory cells (MTIC) in formalin-fixed, paraffin-embedded material. The neoplasms were also examined for Epstein-Barr virus (EBV) DNA by the polymerase chain reaction (PCR). BCMF were independently classified as medullary carcinoma (MC) or infiltrating ductal carcinoma (IDC) by six observers according to the criteria of Pedersen et al. DNA from 35 BCMF was successfully amplified using PCR, but all were negative for EBV DNA. These included, by 4/6 consensus diagnosis, 16 MC, 18 IDC, and one BCMF which failed to achieve consensus diagnosis. MTIC were present to a mild degree in 19 BCMF (37%) and to moderate to severe degrees in 33 (63%). MTIC were predominantly (> or = 75%) lymphocytic in 31 BCMF (13 MC, 16 IDC, two without consensus diagnostic agreement), and plasmacytic in 10 (six MC, four IDC); equal proportions of lymphocytes and plasma cells occurred in 11 (six MC, five IDC). Lymphocytic MTIC were mostly CD45RO+/CD3+ T-cells in nearly all cases, and showed a predominant CD3+/CD4+ and CD3+/CD4- immunophenotype in 36% and 64% of cases, respectively. Natural killer cells (CD57+) and histiocytes (MAC 387+) were virtually absent. The number, cell type, and T-cell subsets of the MTIC were unrelated to consensus diagnosis, axillary lymph node status, or overall survival. EBV is unassociated with MC, despite the histologic similarities of MC to EBV-associated lymphoepithelial lesions of other organs.(ABSTRACT TRUNCATED AT 250 WORDS)

The affinity of ractopamine, clenbuterol, and L-644,969 for the beta-adrenergic receptor population in porcine adipose tissue and skeletal muscle membrane

The affinities (Ki) with which ractopamine (RA), clenbuterol (CB), and L-644,969 (L6) bind the beta-adrenoceptor populations of adipose tissue (middle and outer subcutaneous [SQ] layers) and longissimus (LM) and semitendinosus (ST) muscle were determined. Within a given agonist, Ki values (nanomolar) were similar among tissues, except for RA, which had a higher (P < or = .05) affinity (lower Ki) for middle SQ adipose tissue than for outer SQ adipose and both muscles. For all tissues, binding affinities were greatest for CB (126), followed by L6 (350) and RA (856, exclusive of middle SQ adipose). The data indicate that both adipose and muscle tissues are targets of CB, RA, and L6 in vivo, and that tissue preferences of the agonists cannot be established from affinity data alone. The relatively constant affinity of the agonists for the various tissues examined implies that if tissue preferences exist, the efficiency with which postreceptor events are invoked by these agonists is the determining factor.

(-)-[3H]-dihydroalprenolol binding to beta-adrenergic receptors in porcine adipose tissue and skeletal muscle membrane preparations

We have characterized binding of (-)-[3H]dihydroalprenolol (DHA) to the beta-adrenergic receptor population in membrane from longissimus and semitendinosus muscles and subcutaneous adipose tissue (middle and outer layers) of pigs weighing 100 to 120 kg at slaughter. Linearity of specific binding with increasing membrane protein concentration was confirmed for muscle and adipose tissue. Specific binding was saturable; the beta-receptor population showed a high affinity for the radioligand. Half-maximal binding was achieved at similar concentrations of the tracer (.48 to .73 nM) in all tissues. Maximal binding (B max) per milligram of protein for skeletal muscle was approximately half of that for adipose tissue (P < or = .05) and was greater (P < or = .05) in membrane from the middle than in membrane from the outer layer of adipose tissue. Adipocyte membrane preparations yielded Kd estimates similar to those obtained with adipose tissue, but Bmax values were greater (P < or = .05). Kinetic rate constants were estimated and used to calculate the Kd for comparison to that derived from nonlinear regression analysis of Scatchard plots. Association (k1) and dissociation (k2) estimates were similar between tissues and the resulting Kd values were comparable to those derived from equilibrium data. Stereospecificity of binding was verified using the (-) and (+) isomers of the beta-adrenergic agonist isoproterenol; selectivity for the (-) form ranged from 8- to 19-fold. Overall, the most notable differences among tissues were in receptor density expressed per milligram of protein. Kinetic rate constants, Kd estimates, and the degree of selectivity for (-)-isoproterenol were similar.

Sarcomatoid carcinomas (carcinosarcomas) of the gastrointestinal tract: a review

This review discusses sarcomatoid carcinomas of the gastrointestinal tract, rare malignant neoplasms that demonstrate both epithelial and mesenchymal differentiation. The clinical, histological, immunohistochemical, and ultrastructural features are described. Practical problems in the differential diagnosis of these tumors are also discussed.

Radiotherapy for basaloid squamous cell carcinoma of the head and neck

Basaloid squamous cell carcinoma (BSCC) of the head and neck is a recently described high-grade variant of squamous cell carcinoma. It is a biologically virulent neoplasm with a propensity for nodal, as well as systemic, metastases. Because of the limited number of published reports, we reviewed data from patients of the University of Virginia Health Sciences Center and identified 16 cases of BSCC. The intent of this study was to determine the role of radiotherapy in the treatment of BSCC and better define the clinical features of this entity. Radiotherapy alone, or in combination with surgery, resulted in excellent local control rates. Distant metastases, chiefly pulmonary, occurred in more than half of the patients.

Plasmacytoid monomorphic adenoma of salivary glands. Absence of myogenous differentiation and comparison to spindle cell myoepithelioma

The immunohistochemical and ultrastructural features of two salivary gland monomorphic adenomas composed of plasmacytoid cells (so-called plasmacytoid myoepitheliomas) were studied to determine if the plasmacytoid cells contained detectable evidence of myogenous differentiation. The results were compared with the immunohistochemical profile of three salivary gland myoepitheliomas of spindle-cell type. The plasmacytoid tumors were each immunoreactive for vimentin, cytokeratin, S100 protein, and glial fibrillary acidic protein (GFAP). They were negative for muscle-specific actin (MSA), smooth-muscle actin (SMA), and desmin. Conversely, two of three spindle-cell myoepitheliomas were immunoreactive for MSA and SMA, in addition to vimentin, cytokeratin, and S100 protein. One tumor also contained focal positivity for desmin and GFAP, and a single spindle-cell tumor was vimentin-positive only. Ultrastructurally, plasmacytoid cells were characterized by focal desmosomes, basal lamina, and abundant intermediate cytoplasmic filaments. Dense bodies typical of smooth-muscle cells and actin-sized filaments were absent. Immunohistochemically and ultra-structurally, the plasmacytoid cells lack any evidence of myogenous differentiation and should not be considered a subtype of myoepithelioma.

Bacteriological analysis of high-speed handpiece turbines

The microbial contamination of handpiece turbines was examined clinically. In 20 handpieces, no bacterial growth was found on any culture from an autoclaved or non-autoclaved handpiece group. But growth occurred in the positive control inoculated with fresh whole human saliva. An adjunctive investigation with saliva substitute showed that oral fluids can contaminate handpiece turbines during simulated clinical treatment.

Intraarticular synovial sarcoma

A 43-year-old man presented with decreased range of motion in his left knee and a painful medial joint mass that was grossly visible. Arthroscopy demonstrated a mobile, flat mass 3 cm in diameter in the knee joint that seemed to be loosely tethered to the synovium. The mass was excised, and light microscopic examination demonstrated a biphasic synovial sarcoma. There was no transition with the attached normal synovium. Immunohistochemically, the epithelial component was intensely positive for epithelial membrane antigen and cytokeratins (CAM 5.2 and AE 1/AE 3), and the spindle cell component was focally positive for these markers. The patient has no evidence of disease 9 years after only local excision. Although the term synovial sarcoma suggests a relationship to normal synovium, only rarely has truly intraarticular disease been reported.

Basaloid squamous cell carcinoma of the head and neck. A clinicopathologic and immunohistochemical study of 40 cases

In this study of 40 cases of basaloid squamous cell carcinoma, 83% arose in the pyriform sinus, base of tongue, tonsil, and larynx. The 35 men and five women ranged in age from 27 to 88 years (median 62). In patients for whom social habits were recorded, 24 of 26 patients were smokers and 22 of 25 drank ethanol. Most presented with stage III or IV disease. Twenty-seven patients had regional metastases at the time of presentation and 15 developed distant metastases. Seventeen patients died with disease (median survival 18 months). The tumors were composed of moderately pleomorphic basaloid cells forming nests, cords, and frequent cribriform patterns. Squamous dysplasia of surface mucosa, focal squamous differentiation within invasive basaloid squamous cell carcinoma, or foci of conventional squamous cell carcinoma were present, alone or in combination. All studied neoplasms were immunohistochemically positive for keratins with the 34 beta E12 antibody. Approximately 80% were immunoreactive using AE1/AE3 or CAM 5.2. Epithelial membrane antigen, carcinoembryonic antigen, and S100 protein were found in 83%, 53%, and 39%, respectively, of the cases. Diffuse, weak immunoreactivity for neuron-specific enolase was seen in 75% of tumors. Synaptophysin, chromogranin, muscle-specific actin, and glial fibrillary acidic protein were absent. Basaloid squamous cell carcinoma has been confused with adenoid cystic carcinoma and small cell undifferentiated carcinoma, but is usually distinguishable in routine hematoxylin and eosin-stained sections, or, in rare problematic cases, with the aid of immunohistochemical studies. Distinction is warranted because the biologic behavior of basaloid squamous cell carcinoma differs from that of both of these lesions.

Immunoreactivity for BER-EP4 in adenocarcinomas, adenomatoid tumors, and malignant mesotheliomas

Ber-EP4 is a recently characterized monoclonal antibody directed against a cell surface glycoprotein that is putatively present on human epithelial cells but lacking on the mesothelium. To investigate the diagnostic efficacy of Ber-EP4 in distinguishing adenocarcinoma from mesothelioma, we studied formalin-fixed, paraffin-embedded sections from well-documented cases of adenocarcinoma (120 cases), adenomatoid tumor (nine cases), and malignant mesothelioma (49 cases). Of the 120 adenocarcinomas, 103 (86%) showed membranous Ber-EP4 positivity, with diffuse reactivity noted in 82 cases and focal staining in 21 cases. Reactivity with Ber-EP4 was also observed in two of nine adenomatoid tumors (22%) and 10 of 49 mesotheliomas (20%). Staining in the mesotheliomas was restricted to epithelioid areas and generally focal. In one mesothelioma, however, Ber-EP4 stained the majority of neoplastic cells. In contrast to previous reports, we conclude that positivity with Ber-EP4 does not exclude the diagnosis of mesothelioma. Nonetheless, most Ber-EP4-positive mesotheliomas exhibit only focal positivity, as opposed to the extensive staining commonly observed in adenocarcinomas. Ber-EP4 has diagnostic utility in the discrimination of mesothelioma from adenocarcinoma, but it is best utilized in an antibody panel that includes other markers of carcinomatous differentiation.

Lobular capillary hemangioma. An immunohistochemical study including steroid hormone receptor status

Twenty-one lobular capillary hemangiomas (LCH), including lesions from six pregnant patients, were examined by immunohistochemical analysis. Antibodies to estrogen and progesterone receptor proteins were used to determine whether these steroid hormones play a direct role in LCH development and growth. All 21 LCHs were negative for both receptor proteins. Contrary to the association of LCH with pregnancy and oral contraceptive use, the absence of these steroid receptors strongly suggests that estrogen or progesterone are not directly involved in the formation of these lesions. All 21 LCHs were stained with Ulex europaeus lectin and with a panel of antibodies directed against cytokeratin, vimentin, Factor VIII, collagen Type IV, and muscle-specific actin. Endothelial cells in LCH, both in cellular proliferations with poorly formed lumens and in well-formed capillaries, were labeled by Factor VIII, Ulex europaeus lectin, and vimentin. A population of concentrically arranged, perivascular spindle-shaped cells was highlighted by positive staining for muscle-specific actin, collagen Type IV, and vimentin. The spindled cells were associated with both well-developed and immature vessels in all lesions. The appearance, immunophenotype, and location of these cells is consistent with a pericytic origin. Although the intimate association of both endothelial cells and pericytes suggests a reactive, as opposed to neoplastic, origin, other benign vascular tumors traditionally considered neoplastic have a similar bicellular composition. Accordingly, the findings neither support nor refute a neoplastic origin for LCH.

Estrogen inhibits calbindin-D28k expression in mouse uterus

The cellular localization and hormonal controls of calbindin-D9k expression in the rodent reproductive tract have suggested new functions for this protein. The present studies were undertaken to extend the earlier studies of calbindin-D9k to the related protein, calbindin-D28k. Immunohistochemical studies revealed that calbindin-D28k was absent from female rat reproductive tissues, but was abundantly expressed in immature mouse uterus and oviduct. Immunoreactivity was restricted to the endometrial and glandular epithelium of the uterus and the oviductal epithelium. Neither 1,25-dihydroxyvitamin D- nor strontium-containing diets (to blunt 1,25-dihydroxyvitamin D production) affected expression of calbindin-D28k. Uterine, but not oviductal, calbindin-D28k decreased markedly at sexual maturity; this pattern persisted in pregnant mice and was reproduced in immature mice by the administration of estradiol (3 micrograms/day for 3 days). RNA extraction and Northern analyses demonstrated that estrogen markedly decreased calbindin-D28k mRNA abundance in the uterus, but not in the oviduct. These findings suggest that estrogen affects mammalian calbindin-D28k expression and represent a rare example of estrogen-induced down-regulation of gene expression.

Cytokeratin expression in adrenocortical neoplasia: An immunohistochemical and biochemical study with implications for the differential diagnosis of adrenocortical, hepatocellular, and renal cell carcinoma

The immunostaining patterns of adrenocortical tumors are not clearly defined, primarily due to their inconsistent expression of cytokeratins (CK). To address this issue and to investigate whether adrenocortical tumors can be immunohistochemically differentiated from histologically similar tumors arising from the kidney and liver, we studied four normal adrenal glands, two adrenocortical adenomas (ACAs), 31 adrenocortical carcinomas (ACCs), 37 renal cell carcinomas (RCCs), and 33 hepatocellular carcinomas (HCCs) with anti-CK antibodies AE1, CAM 5.2, UCD/PR10.11, 35BH11, PKK1, and Ks19.1, as well as antibodies to vimentin (VIM), epithelial membrane antigen (EMA), and HMFG-2. Normal adrenal cortical cells showed variable staining with all anti-CK antibodies on fixed and frozen sections. In contrast, only one of two fixed ACAs stained with a single anti-CK, although both neoplasms reacted with multiple anti-CK antibodies on frozen sections. Similarly, 20 of 31 fixed ACCs contained VIM, but only one tumor stained for CK; frozen sections of this and another, previously negative tumor, however, stained with most of the anti-CK antibodies tested. One-dimensional Western immunoblot analysis confirmed the presence of CKs 18 and 19 in two examples of normal adrenal cortex, one ACA, and the ACC immunohistochemically positive on fixed and frozen sections, with CK 19 identified in the ACC that was positive on frozen section alone. All fixed HCCs and most RCCs stained with multiple anti-CK antibodies (33 and 34 cases, respectively), with a proportion of tumors positive for VIM (six and 22 cases, respectively), EMA (seven and 30 cases, respectively), and HMFG-2 (15 and 28 cases, respectively). The results suggest that CK expression is diminished in most adrenocortical tumors to levels too low to be recognized following the deleterious effects of fixation. While the immunohistochemical absence of CK, EMA, and HMFG-2 in fixed sections in the majority of ACCs is distinctive, sufficient phenotypic overlap exists such that differentiation between RCC and HCC may not be possible in an individual case.