Adenoid Structures Research Articles

FAP-α is an effective tool to evaluate stroma invasion of lung adenocarcinoma

The main difficulty in the diagnosis of atypical in situ adenocarcinoma lies in the distinction between true and false stromal invasion. Moreover, how to identify local alveolar wall collapse in situ lung adenocarcinoma and how to identify whether the trapped adenoid structure around scar is an invasion component have become the key points for accurate diagnosis of lung adenocarcinoma. In the present study, we detected 40 cases of lung adenocarcinoma in situ and 40 cases of invasive adenocarcinoma by using immunohistochemical techniques. We found FAP-α had not immunreactivity in the stroma of adenocarcinoma in situ. However, it stained in the stroma of invasive areas in lung adenocarcinoma. FAP-α staining pattern could represent hyperplastic myofibroblast and demonstrated the true invasion of stroma. This study provides strong evidence that FAP-α is an effective tool to evaluate the presence or absence of stroma invasion of lung adenocarcinoma. Our findings will contribute to the accurate diagnosis of lung invasive adenocarcinoma.

A cytodiagnosis of adenoid cystic carcinoma of the tracheobronchial tree through a systematic clinical case comparison and analysis

BackgroundPrimary adenoid cystic carcinoma (AdCC) of the tracheobronchial tree is very rare with a high risk for recurrence and metastasis. The diagnosis of AdCC by histologic and immunohistochemical means has been well studied clinically. However, the identification of AdCC by cytologic features remains elusive due to the atypical features the cancer presents. This study aimed to describe the cytologic features of AdCC by using bronchial brushing, which could aid in distinguishing AdCC from other pulmonary carcinomas.MethodsThe cytopathological features of bronchial brushing smears collected from seven cases were histologically diagnosed as AdCC. The defined cytologic features, which could potentially be diagnostic, were systemically analyzed.ResultsFour out of the seven cytologic cases were inconcordance with the histologic diagnosis and cytologically classified as positive for malignant cells, small cell carcinoma, or atypical cells. Three cases showed a characteristic adenoid structure and magenta stroma forming globule, which was distinguished from the four cases. Cytologically, the above mentioned three cases were uniform with relatively small bland nuclei and little cytoplasm. In this study, only one case showed atypical polygonal medium-sized cells with conspicuous nucleoli.ConclusionsUnlike fine-needle aspiration cytology, magenta stroma globules might offer an alternate clue for cytodiagnosis of AdCC clinically. Bronchial brushings cytology was more present in bland uniform cells with high nuclear to cytoplasmic ratios and background mucoid substance. More cases should be collected and confirmed using histopathology with careful film reading to reduce the rate of misdiagnosis.

AMELOBLASTOMA WITH ADENOID STRUCTURES: A SURVEY OF 6 NEW CASES

<h3>Objectives</h3> The aim of the present study was to analyze the clinicopathologic profile of ameloblastomas with adenoid structures. <h3>Study Design</h3> This retrospective observational study consisted of cases diagnosed as ameloblastoma between 2014 and 2021 that were microscopically reviewed. The included cases were only those exhibiting focal (<50% of the tumor) or predominant (>50% of the tumor) duct-like spaces of variable size, lined by cuboidal to columnar cells containing mucoid material. Clinical data were collected from biopsy request forms and tabulated for descriptive analyses. <h3>Results</h3> There were 125 ameloblastomas (1.2%; ∼15 cases per year). Adenoid structures were observed in 6 samples (4.8%) from 5 males and 1 female, with a mean age of 41 years (range, 25 to 61). The posterior region of the mandible was most frequently affected (<i>n</i> = 5). The cases presented as asymptomatic unilocular (<i>n</i> = 1) or multilocular (<i>n</i> = 4) radiolucency. Three cases exhibited predominant adenoid structures, 1 of which exhibited exuberant dentinoid material. The other 3 cases of conventional ameloblastoma showed focal areas of adenoid features. <h3>Conclusions</h3> Adenoid structures in ameloblastoma appear to be an uncommon event of unknown clinical significance and may be associated with dentinoid material and should not be misinterpreted as an adenomatoid odontogenic tumor.

Clinicopathological features of gastric adenocarcinoma with enteroblastic differentiation: a report of twelve cases

Objective: To investigate the clinicopathological features, immunophenotype, diagnosis and differential diagnosis of gastric adenocarcinoma with enteroblastic differentiation (GAED). Methods: Twelve cases of GAED diagnosed in Fujian Provincial Hospital from August 2019 to August 2020 were collected. HE staining, immunohistochemistry and HER2 gene amplification were evaluated. In addition, 343 cases of gastric adenocarcinoma diagnosed in the same period were used as the control group to compare the clinicopathological differences between them. Results: The 12 cases of GAED included 10 males and 2 females, aged 59-75 years (median 66.5 years). The main clinical manifestations were abdominal pain, melena with hematemesis; nine tumors were ulcerative and three were protuberant. The tumor diameter ranged from 1.5 to 9.5 cm (median 6.0 cm). Histologically, the tumor cells were arranged in tubular, papillary, cribriform, or adenoid structures. The cells were cuboidal to columnar, with relatively distinct cell boundaries and abundant clear or slightly eosinophilic cytoplasm. Immunohistochemically, tumor cells were positive for SALL4 (12/12), glypican-3 (9/12), AFP (5/12), CDX2 (8/12), CD10 (3/12), p53 mutated (10/12), HER2 (2/12, 3+), and both cases showed HER2 gene amplification by fluorescence in situ hybridization. Compared with common gastric adenocarcinoma, GAED showed higher rate of vascular invasion and tumor progression (P<0.05), but there were no significant differences in age, sex, degree of differentiation, nerve invasion, lymph node metastasis, pT stage, pN stage and pM stage (P>0.05). Conclusions: GAED is a rare type of gastric adenocarcinoma. Pathologically, GAED has both embryonal and intestinal phenotypes. In terms of biological behavior, it is more invasive. GAED needs to be distinguished from common gastric adenocarcinoma in clinical diagnosis.

Gastric Mixed Neuroendocrine-Nonneuroendocrine Neoplasm: A rare case report

Objective: The incidence of gastric neuroendocrine neoplasms is less than 1%. They are seen as combined tumors with non-neuroendocrine neoplasms at a rate of approximately 7%. This study aims to share the case of mixed neuroendocrine and non-neuroendocrine cancer with the literature.&#x0D; Case: Endoscopic biopsies were taken from the tumoral mass detected in the gastric cardia region at endoscopy in a 60-year-old male patient that has complaints of weight loss and epigastric pain. Histopathological examination revealed malignant tumor infiltration that consisting of neuroendocrine cells with large nuclei and narrow cytoplasm in some areas and adenoid structures composed of atypical cells with pleomorphic large nuclei in some areas. Strong staining was observed in neuroendocrine areas with neuroendocrine markers such as synaptophysin and Chromogranin. Ki-67 proliferative index and mitotic activity were high in neuroendocrine neoplasm areas. The case was reported as a high-grade neuroendocrine-non neuroendocrine mixed neoplasm.&#x0D; Conclusion: Gastric Mixed Neuroendocrine-Nonneuroendocrine neoplasms are rare cases and correct diagnosis and grading are important in the treatment and patient follow-up protocol.

Acantholytic squamous cell carcinoma: Pathological study of three cases in Ecuador

&lt;p&gt;Adenoid squamous cell carcinoma is an uncommon histopathological variant of squamous cell carcinoma characterized by acantholysis of tumor cells creating pseudolumina and the appearance of glandular differentiation. It is also known as pseudoglandular, pseudoangiosarcomatous, adenoid, epithelioma dyskeratoticum, or adenoacanthoma. In this article, we describe and analyze three cases of acantholytic cell carcinoma. The purpose is to verify if the data of our cases can be validated with scientific information. All our cases presented lesions in the face, and in one of them the developed tumor on the skin showed actinic keratosis. The other two tumors were located in the right side of the face, and both were big: the bigger tumor was approximately 8 × 4 cm and the other one with a size of 6 × 2.5 cm. Due to the size and location, they were both send to the oncologist for treatment. One of our cases showed metatypical carcinomas accompanied by acantholytic variant of squamous cell carcinoma. None of our cases presented metastasis. The histopathological finding were keratinized squamous tumor cell type, adenoid structures with round spaces with a defined wall of at least one-cell width, and spaces with isolated or group of dyskeratotic cells.&lt;/p&gt;

Acantholytic squamous cell carcinoma: Pathological study of three cases in Ecuador

&lt;p&gt;Adenoid squamous cell carcinoma is an uncommon histopathological variant of squamous cell carcinoma characterized by acantholysis of tumor cells creating pseudolumina and the appearance of glandular differentiation. It is also known as pseudoglandular, pseudoangiosarcomatous, adenoid, epithelioma dyskeratoticum, or adenoacanthoma. In this article, we describe and analyze three cases of acantholytic cell carcinoma. The purpose is to verify if the data of our cases can be validated with scientific information. All our cases presented lesions in the face, and in one of them the developed tumor on the skin showed actinic keratosis. The other two tumors were located in the right side of the face, and both were big: the bigger tumor was approximately 8 × 4 cm and the other one with a size of 6 × 2.5 cm. Due to the size and location, they were both send to the oncologist for treatment. One of our cases showed metatypical carcinomas accompanied by acantholytic variant of squamous cell carcinoma. None of our cases presented metastasis. The histopathological finding were keratinized squamous tumor cell type, adenoid structures with round spaces with a defined wall of at least one-cell width, and spaces with isolated or group of dyskeratotic cells.&lt;/p&gt;

Intradermal nevocellular nevus with adenoid features: Report of a case

Intradermal nevocelluar nevus is a very common hamartomatous neoplasm of the skin. The author herein reports two tumors of intradermal nevocelluar nevus in the neck occurring in a 55-year-old woman. The tumors were characterized histologically by typical intradermal nevocelluar nevus with significant areas of adenoid or glandular formations. In both tumors, hair follicles were seen in centers of the tumors. The cellular features of the adenoid areas were the same as those of solid areas. In solid areas, vague vacuolated and obvious vacuolated cells were recognized in some areas. In solid areas of the surface and lateral areas of the tumors also showed clear cut adenoid features without vacuolations. The adenoid features showed mild depositions of hemosiderins. There were gradual merges between solid areas and adenoid or glandular areas. Histochemically, the tumor cells including adenoid structures had glycogen, but had no mucins. Immunohistochemically, cells of both tumors were strongly positive for S100 protein, vimentin, NSE, NCAM, and bcl-2, and were weakly positive for synaptophysin and chromogranin. The tumor cells showed low cell proliferative potential; the Ki-67 labeling index was 2%. The tumor cells including adenoid structures were negative for CK AE1/3, CK CAM5.2, desmin, smooth muscle actin, HMB45, p53, p63, CD31, laminin, type 4 collagen, CEA. CD34, CA125, CA19-9, CD45, GFAP, KIT, PDGFRA, CD68, estrogen receptor, progesterone receptor, EMA, MUC1, MUC2, MUC5AC, and MUC6. These histological, histochemical, and immunohistocheimical findings strongly suggested that the present two tumors with adenoid structures belong to intradermal nevocelluar nevus. The formation of the adenoid architectures in the intradermal nevocelluar nevus was discussed. Possible mechanisms appear loss of cell adhesions molecules. The adenoid structures seem not to be degenerative ones. Pathologists should be aware that intradermal nevocelluar nevus may show adenoid structures to avoid diagnostic confusions, for example adenoma and adenocarcinoma of skin appendages. The occurrence of this hitherto undescribed condition in two intradermal nevocelluar nevus in a patient may imply genetic lineage. To elucidate the mechanisms of adenoid structures in intradermal nevocelluar nevus seems future work.

Primary carcinoid tumor of the kidney with estrogen and progesterone receptor expression.

Primary carcinoid tumors are uncommon neoplasms in the kidney. The current study presents a case of primary carcinoid tumor of the kidney in a 49-year-old female who suffered from painless gross hematuria for half a month. Left hydronephrosis, a horseshoe kidney and a space-occupying lesion of the left ureter were found by abdominal computed tomography scans and ultrasonic testing. Surgery was performed and an oval tumor was found under the left ureter; the tumor and left kidney were excised completely. The neoplasm was composed of solid nests of cells, trabeculae, adenoid structures and anastomosing cords in a loose and myxoid background. The tumor cells, which were consistent in volume, exhibited centrally oval nuclei with inconspicuous nucleoli, and eosinophilic finely granular cytoplasm. Upon immunohistochemical staining, the neoplastic cells were positive for AE1/AE3, vimentin, synaptophysin, chromogranin A, estrogen receptor and progesterone receptor, while being negative for epithelial membrane antigen, inhibin A, cluster of differentiation (CD)99, S-100 and CD10. Based on the histological characteristics, a diagnosis of primary carcinoid tumor of the left kidney was formed. The patient did not receive further treatment. The total follow-up period was 18 months after the surgery and repeated imaging examinations every 6 months revealed no recurrence.

Characterization of gastric cancer models from different cell lines orthotopically constructed using improved implantation techniques

To develop orthotopic gastric cancer mouse models from different cell lines and characterize the tumor features to assist further in preclinical trials and clinical treatment strategies. Human gastric cancer SGC-7901 and BGC-823 cell suspensions were injected subcutaneously into nude mice to develop solid tumors, and tumor tissue pieces were then implanted under the serous coat of the stomach. An autopsy was performed on all animals of the SGC-7901 and BGC-823 models to observe the primary tumor growth and metastases using pathological and immunohistochemical methods. Both models showed large tumors in situ resulting in pressure and infiltration of the adjacent organs. The gastric cavity became smaller, along with stenosis of the cardia or pylorus. There were biological and statistical differences between the two models. The metastasis rate in involved organs (lymph nodes, kidney, spleen, testis) was significantly higher in the BGC-823 model compared to the SGC-7901 model (P < 0.05 or P < 0.01). The median survival of the BGC-823 model was shorter than that of SGC-7901 (23 d vs 84 d, P < 0.05). Histopathologically, the primary tumor and metastatic lesions of the two models showed obvious atypia and mucus in the cytoplasm. Compared with the SGC-7901 model, BGC-823 appeared more poorly differentiated (absence of adenoid structure), had a smaller volume, and richer capillary structure. Immunohistochemical staining revealed cytokeratin 20 and epithelial membrane antigen expression was positive in the SGC-7901 tumors, while negative in BGC-823 ones. Models using the SGC-7901 and BGC-823 cell lines were established which could function in gastric cancer research on carcinogenesis mechanism and drug discovery. The two models showed different tumor behavior and the latter was more malignant than the former.

Musashi1 and Hairy and Enhancer of Split 1 High Expression Cells Derived from Embryonic Stem Cells Enhance the Repair of Small-Intestinal Injury in the Mouse

Embryonic stem cells have great plasticity. In this study, we repaired impaired small intestine by transplanting putative intestinal epithelial stem cells (Musashi1 and hairy and enhancer of split 1 high expression cells) derived from embryonic stem cells. The differentiation of definitive endoderm in embryoid bodies, derived from male ES-E14TG2a cells by the hanging-drop method, was monitored to define a time point for maximal induction of putative intestinal epithelial stem cells by epidermal growth factor. Furthermore, to evaluate the regenerative potential of intestinal epithelium, these putative stem cells were engrafted into NOD/SCID mice and female mice with enteritis. Donor cells were located by SRY DNA in situ hybridization. The results revealed that definitive endodermal markers were highly expressed in 5-day embryoid bodies. These embryoid body cells were induced into putative intestinal epithelial stem cells on the 5th day of epidermal growth factor administration. Grafts from these cells consisted of adenoid structures and nonspecific structural cells with strong expression of small-intestinal epithelial cell markers. In situ hybridization revealed that the donor cells could specifically locate in damaged intestinal epithelium, contribute to epithelial structures, and enhance regeneration. In conclusion, the Musashi1 and hairy and enhancer of split 1 high expression cells, derived from mouse embryonic stem cells, locate predominantly in impaired small-intestinal epithelium after transplantation and contribute to epithelial regeneration.

Histopathological changes in rainbow trout ( Oncorhynchus mykiss) after exposure to sublethal composite nitrogen fertilizers

Subchronic toxicity of composite inorganic fertilizers such as ammonium sulfate [fertilizer A; (NH 4) 2SO 4; 21% NH 4-N)], composite fertilizer 15-15-15 (fertilizer B; commercial formulation: 15% NH 4-N, 15% phosphorus, and 15% potassium oxide), and composite fertilizer 25-5-10 (fertilizer C; commercial formulation: 25% NH 4-N, 5% phosphorus, and 10% potassium oxide) on the skin, liver, kidney, pancreas, and gills of the juvenile rainbow trout ( Oncorhynchus mykiss) was studied in two-week toxicity tests under static-renewal test conditions. Fish exposed to sublethal concentrations of fertilizers did not show any behavioral abnormality compared to control groups. Histological lesions were observed in skin, gills, liver, pancreas, and trunk kidney of the fish. In the epidermis, degenerated/vacuolated epithelial cells, microcystic dilatations, and intracellular edema of mucus cell were observed. Liver had swollen and degenerated hepatocytes without losing adenoid structure. Hematopoietic tissues had necrosis and vacuolar degeneration on proximal tubules of the kidney. In order, the most affected organs were skin, liver, and kidney.

Painful cutaneous metastasis in a patient with laryngeal adenocarcinoma

Conflict of interest: there are no conflicts of interest A 70‐year‐old man presented with a 1‐week history of a painful nodule in the skin of his upper abdomen. Seven months previously, he had had a laryngectomy for laryngeal adenocarcinoma (American Joint Committee on Cancer stage T3N1M0) but was otherwise well. On examination, he had a spherical, smooth, firm, tender, reddish‐purple, 8 × 8‐mm nodule located 120 mm above the umbilicus (Fig. 1a, after punch biopsy). The lesion was well‐defined but fixed to the deep layers. Histopathological examination of a punch biopsy specimen confirmed skin metastasis, as suspected clinically. Wide local excision was performed, and the histology of the skin lesion identified it as a metastatic adenocarcinoma, with formed adenoid structures and signet‐ring cells. Sections of the surgical specimen revealed adenocarcinoma infiltrating the dermis, with the overlying epidermis intact. The tumour cells contained hyperchromatic nuclei and abundant cytoplasm (Fig. 1b). There was no evidence that the tumour had invaded the epidermis, the vessel walls or any small peripheral nerves.

In Vivo Confocal Microscopy of Normal Conjunctiva and Conjunctivitis

To analyze the appearance of normal conjunctiva and conjunctival inflammation by in vivo confocal microscopy. Conjunctiva of 15 normal patients and 21 patients with conjunctivitis including bacterial, papillary, follicular, granulomatous, and cicatrizing disease were analyzed by the Heidelberg retina tomograph (HRTII)/Rostock cornea modul (RCM). Scans of normal bulbar and tarsal conjunctiva corresponded well to the established anatomy except for a prominent, thickened epithelial basement membrane observed by in vivo microscopy. Presumed goblet cells were visible throughout the conjunctival epithelium. Adenoid structures and hair follicles were discernible in the tarsal conjunctiva in vivo. Conjunctival perfusion could be observed directly. Acute and chronic inflammatory cells, conjunctival papillary, and follicular reactions, as well as conjunctival cicatrization, could be discriminated. In a patient with conjunctival granuloma, in vivo confocal microscopy disclosed suture material inside the lesion. Confocal microscopy using near-infrared laser light is a useful new tool in the analysis of conjunctival tissue in vivo. It is a valuable aid in the differential diagnosis of conjunctival inflammation and thus may guide therapeutical decisions.

Adenoid glioblastoma arising in a patient with neurofibromatosis type‐1

An unusual case of glioblastoma with adenoid structures arising in a 30-year-old Japanese woman with neurofibromatosis type-1 (NF1) is reported. The patient was admitted to University of Miyazaki Hospital, complaining of headache, nausea and vomiting. From the neuroradiological findings the patient was diagnosed as having glioblastoma, and the tumor was surgically resected. Histologically, the tumor consisted mainly of dark basophilic cells showing prominent tubular or glandular structures surrounded by large eosinophilic cells, in addition to the typical glioblastoma features in the periphery of the tumor. Both cells showed strong stainability with glial fibrillary acidic protein (GFAP) and S-100 protein immunohistochemically, so that the tumor was classified as adenoid glioblastoma. Several cases of glioblastoma have been reported to reveal the adenoid or epithelioid differentiation. The patients with NF1 are prone to develop malignant tumors including glioblastoma, but no cases representing adenoid glioblastoma associated with NF1 have been reported. This report is considered to be the first case of adenoid glioblastoma arising in a patient with NF1. The recognition of the existence of epithelial features of glioblastoma would be important in differential diagnosis of epithelioid tumors of the brain including metastatic carcinomas.

Lymphocyte subpopulations in hypertrophied adenoid in children

Adenoid hypertophy is a common feature of childhood. It is currently accepted that it is caused by the antigen-stimulated increased activity of lymphocyte B (D. Bani, O. Gallo, O. Fini-Storchi, Intraepithelial lymphocyte subpopulations and dendritic accessory cells in normal and hypertrophic adenoids, Laryngoscope 10 (1994) 869–873). The adenoid decreases its size with age but the accompanying function alterations are not fully understood (L. Zawadzka-Glos, M. Chmielik, M. Wasik, Cell mediated response in hypertrophied tonsils in children, Nowa Pediatr. 4 (1997) 12–13). The understanding of the adenoid structure that undergoes some changes during the growth period is essential for evaluation of indications for adnoidectomy and assessment of its potential results. The aim of this study was to evaluate lymphocyte subpopulations in adenoid according to age. The analysed material was adenoids removed on the grounds of hypertrophy, which caused obstructive symptoms and/or otitis media with effusion onset. In the present study, we did not find any statistically significant differences among lymphocytes B, Th, and Ts subpopulations, respectively, in the adenoids of any of the age groups. We have found a statistically significant CD3 + HLA-DR + cell percentage decrease in the group of children from 5 to 10 and above 10 years of age, respectively. We have also found a statistically significant increase in the percentage of NK (CD3 − CD16 + 56 +) lymphocytes in relation to age. On the grounds of the current study, it may be stated that some changes in lymphocyte subpopulations in the adenoid take place with age.

The Stereoisomeric Fjord-Region Benzo[c]phenanthrene-3,4-Dihydrodiol 1,2-Oxides Malignantly Transform Rat Liver Epithelial Cells

Abstract The rat liver oval cell line OC/CDE 22 was exposed to each of the four optically active fjord-region dihydrodiol epoxides of benzo[c]phenanthrene to investigate their capacity for malignant transformation of liver cells. All four configurational isomers malignantly transformed OC/CDE 22 cells, resulting in a similar colony-forming efficiency in soft agar. Inoculation of the transformed cells into newborn syngeneic rats produced an extremely high incidence of carcinomas with a short latency period. The induced carcinomas displayed cholangiocellular, adenoid and solid growing structures. Thus, the fjord-region dihydrodiol epoxides of benzo[c]phenanthrene are able to efficiently transform rat liver cells. Furthermore, experimental evidence is presented that proliferation plays a central role in liver cell transformation mediated by polycyclic aromatic hydrocarbons.

Effect of acupuncture on immunologic function and histopathology of transplanted mammary cancer in mice

This experiment mainly describes the effects of acupuncture on immunologic function and histopathology of transplanted mammary cancer in mice. The results were as follows: in acupuncture group, NK cell activity and T-lymphocyte positive rate of acid alpha-naphthyl acetate esterase (ANAE) and lymphocyte transformation rate were all increased. Compared with the control group, there was a significant difference (P < 0.01). The difference was insignificant, when compared with normal group (P > 0.05). Comparing the pathology grading of acupuncture group with control group, it showed marked difference in pathological section (P < 0.01). Adenoid structure and the degree of lymphocytic infiltration also have marked difference between acupuncture and control group (P < 0.05). Less tumour volume in acupuncture than control group were observed (P < 0.01). This indicated that acupuncture might increase the immunologic function of transplanted mammary cancer in mice and inhibit the growth of mammary cancer and enhance both differentiation level of mammary cancer cells and lymphocytic infiltration. Possibly acupuncture mightt reduce the malignancy of mammary cancer cells.

Malignant transformation of the liver tumour precursor cell line OC/CDE 22 by the four stereoisomeric fjord region 3,4-dihydrodiol 1,2-epoxides of benzo[c]phenanthrene.

In previous work we established the rat liver oval cell line OC/CDE 22 in order to study in vitro mechanisms of liver cell transformation. We have now exposed OC/CDE 22 cells to each of the four optically active fjord region dihydrodiol epoxides of benzo[c]phenanthrene to investigate their capacity for malignant transformation of liver cells. All four configurational isomers, which are among the most potent carcinogenic metabolites of polycyclic aromatic hydrocarbons tested in murine tumour models, malignantly transform OC/CDE 22 cells at a 2 microM dose level, resulting in a similar colony-forming efficiency in soft agar. Inoculation of the transformed cells into newborn syngeneic rats produced an extremely high incidence of carcinomas with a short latency period. The induced carcinomas displayed cholangiocellular, adenoid and solid growing structures. Neither cell growth in soft agar nor induction of tumor formation in newborn rats were achieved if confluent OC/CDE 22 cell cultures were exposed to each of the four stereoisomers and left in the confluent state for 4 weeks. In contrast, if confluent cells were exposed to the four stereoisomers, immediately split and then subcultured as usual, full transformation was accomplished. Our results indicate that the fjord region dihydrodiol epoxides of benzo[c]phenanthrene are highly efficient transforming agents for rat liver cells and that proliferation plays a pivotal role in the liver cell transformation process induced by polycylic aromatic hydrocarbons.

Establishment and characterization of a new human oestradiol- and progesterone-receptor-positive mammary carcinoma serially transplantable in nude mice.

A human mammary carcinoma originating from a postmenopausal patient was successfully transplanted into nude mice. According to the adopted criteria the tumour proved to be oestradiol- and progesterone-receptor-positive. Histological studies of the patient tumour revealed a ductal invasive mammary carcinoma with 80% tubular growth pattern. Following transplantation the adenoid structures decreased to 30%; the mitosis rate and grade of malignancy increased. Treatment of the nude mice with 20 micrograms oestradiol benzoate/mouse caused a loss of the oestradiol receptor of the mammary carcinoma. The mammary carcinoma 3366 can be used for testing of antineoplastic substances, antihormones and for studies in regard to down-regulation or blocking of hormone receptors and possible consequences for therapies.