Cryobiopsy increases the diagnostic yield of endobronchial biopsy: a multicentre trial

Forceps, brushes or needles are currently the standard tools used during flexible bronchoscopy when diagnosing endobronchial malignancies. The new biopsy technique of cryobiopsy appears to provide better diagnostic samples. The aim of this study was to evaluate cryobiopsy over conventional endobronchial sampling. A total of 600 patients in eight centres with suspected endobronchial tumours were included in a prospective, randomised, single-blinded multicentre study. Patients were randomised to either sampling using forceps or the cryoprobe. After obtaining biopsy samples, a blinded histological evaluation was performed. According to the definitive clinical diagnosis, the diagnostic yield for malignancy was evaluated by a Chi-squared test. A total of 593 patients were randomised, of whom 563 had a final diagnosis of cancer. 281 patients were randomised to receive endobronchial biopsies using forceps and 282 had biopsies performed using a flexible cryoprobe. A definitive diagnosis was achieved in 85.1% of patients randomised to conventional forceps biopsy and 95.0% of patients who underwent cryobiopsy (p<0.001). Importantly, there was no difference in the incidence of significant bleeding. Endobronchial cryobiopsy is a safe technique with superior diagnostic yield in comparison with conventional forceps biopsy.

Extended Radical Lymphadenectomy in Patients With Urothelial Bladder Cancer:: Results of a Prospective Multicenter Study

PURPOSE

Previous studies demonstrate a positive correlation between postoperative survival and the extent of pelvic lymphadenectomies in patients with bladder cancer. However, the distribution of nodal metastases has not been examined in sufficient detail. Therefore, we conducted a comprehensive prospective analysis of lymph node metastases to obtain precise knowledge about the pattern of lymphatic tumor spread.

MATERIALS AND METHODS

Between 1999 and 2002 we performed 290 radical cystectomies and extended lymphadenectomies. Cranial border of the lymphadenectomy was the level of the inferior mesenteric artery, lateral border was the genitofemoral nerve and caudal border was the pelvic floor. We made every effort to excise and examine microscopically all lymph nodes from 12 well-defined anatomical locations.

RESULTS

Mean total number and standard deviation of lymph nodes removed was 43.1 +/- 16.1. Nodal metastases were present in 27.9% of patients. The percentage of metastases at different sites ranged from 14.1% (right obturator nodes) to 2.9% (right paracaval nodes above the aortic bifurcation). By studying cases of unilateral primary tumors or with only 1 metastasis we observed a preferred pattern of metastatic spread. However, there were many exceptions to the rule and we did not identify a well-defined sentinel lymph node.

CONCLUSIONS

We strongly recommend extended radical lymphadenectomy to all patients undergoing radical cystectomy for bladder cancer to remove all metastatic tumor deposits completely. The operation can be conducted in routine clinical practice and our data may serve as a guideline for future standardization and quality control of the procedure.

DNA cytophotometry and prognosis in typical and atypical bronchopulmonary carcinoids. A clinicomorphologic study of 100 neuroendocrine lung tumors

Surgical material obtained from 100 patients with typical carcinoids (TC) and atypical carcinoids (AC) of the lung (including 100 primary, four residual tumors, and four lymph node or distant metastases) was investigated by conventional histology and scanning DNA cytophotometry. Of the 60 TC (96%), 58 exhibited euploid DNA histograms compared with only 20 (50%) of the 40 AC. The morphologic findings were related to the patients' survival (median observation period, 9 years). Statistical analyses disclosed the histologic type of disease (TC versus AC) and the DNA content of tumors (euploid versus aneuploid) to affect prognosis significantly (p < 0.001). Deaths resulting from tumor were exclusively observed among patients with atypical (eight of 40) or DNA aneuploid carcinoids (eight of 22). Six patients were alive with persistent tumor manifestations 3 to 20 years after initial diagnosis, four with DNA diploid primary carcinoids. The presence of lymph node metastases alone was not associated with poor prognosis as long as the primary tumor or the related metastases showed a diploid DNA content. DNA cytophotometry thus might be regarded as an adjunctive prognostic criterion in individual carcinoid cases.

Absence of RET proto-oncogene point mutations in sporadic hyperplastic and neoplastic lesions of the parathyroid gland

We investigated the possible role of RET proto-oncogene mutations in the development of sporadic hyperplastic, benign, and malignant parathyroid lesions. DNA extracted from paraffin-embedded specimens of forty parathyroid lesions was screened for RET proto-oncogene point mutations in exons 10, 11, and 16 by nonisotopic polymerase chain reaction-based single-strand conformation polymorphism and heteroduplex gel electrophoresis. The nucleotide sequence of samples with aberrant band patterns was identified by nonisotopic direct sequencing of polymerase chain reaction-amplified DNA. Parathyroids of seven patients with multiple endocrine neoplasia type 2A (MEN 2A) and MEN 2B served as positive controls. None of the eight hyperplastic lesions, three cases of parathyromatosis, ten parathyroid adenomas, eleven carcinomas or one normal parathyroid gland contained mutations in each of the three RET exons tested. Six MEN-2A-associated hyperplastic glands exhibited identical band shifts in the polymerase chain reaction single-strand conformation polymorphism analysis of exon 11, which corresponded to a Cys 634-->Arg substitution in the nucleotide sequence analysis (TGC-->CGC), whereas in the MEN 2B parathyroid specimen a point mutation was found at codon 918 of exon 16 (ATG-->ACG), causing a Met 918-->Thr substitution. Our data indicate that RET mutations of the MEN 2 loci in exons 10, 11, and 16 are not involved in the development of sporadically occurring benign or malignant parathyroid lesions. Furthermore, our results are in accordance with the observation that MEN 2A patients with Cys 634-->Arg (germline) mutations have a higher risk of developing parathyroid disease than those with other mutations at codon 634.

[MR tomography in prostatic carcinoma: comparison of conventional and endorectal MRT]

In a prospective study an attempt was made to determine the value of conventional MRI (354 patients) and MRI using the endorectal surface coil (ESC) (36 patients) in the preoperative staging of prostatic carcinoma. Local preoperative staging with conventional MRI was correct in 83.9% and 88.9% with ESC-MRI. Compared to conventional MRI, ESC-MRI was better in the delineation of the prostatic capsule and early detection of infiltration into the neurovascular bundle. Lymph node staging with MRI showed a sensitivity of 54.4% in detecting pelvic lymph node metastasis. MRI is as limited as CT in assessing pelvic lymph node metastasis.

Cytogenetic survey of 32 cancers of the prostate

Cytogenetic studies after short-term culture were performed on 32 adenocarcinomas of the prostate from patients without prior treatment. The tumor specimens, ranging from stage B1 to D1, were obtained by radical prostatectomy or diagnostic biopsies. Fourteen tumors showed a normal diploid chromosome complement in all metaphases examined. Clonal chromosomal alterations were detected in 16 tumor samples and the remaining two cases contained double minute (dmin) chromosomes in some cells. The most frequent numerical changes included loss the Y chromosome and trisomy 7, both found in four cases. The only recurrent structural aberration was del(10)(q24), seen in three cases both as a sole anomaly and within multiple rearrangements. Six patients showed cytogenetically unrelated clones. The occurrence of the chromosomal changes found in this study shows no relationship to certain histopathologic characteristics of the tumors. The recurrent finding of del(10)(q24) as sole anomaly and the evidence for clonal evolution in one patient demonstrates that this change is an early karyotypic event which may be important for the pathogenesis in at least a subset of prostatic cancers.

[Signet ring carcinoma in the urinary tract. Primary tumor or metastases of an occult neoplasm?]

Between 26/2/88 and 23/6/88 we treated four patients with signet ring cell carcinoma of the urinary tract. There was no conformity in clinical development, results of laboratory investigations, histomorphology or symptoms. For the first time, DNA cytophotometry was used to examine histological preparations of urinary signet ring cell carcinoma. This method provides information about the prognosis of the malignant disease, as it reveals the DNA distribution in the tumor cells. In three cases there was a clearly pathologic so-called an-euploid DNA distribution, indicating the high malignant potency of this tumor entity.

Immunocytochemical differential diagnosis of diffuse malignant pleural mesotheliomas--a clinicomorphological study of 158 cases

Formalin-fixed paraffin-embedded material of 158 diffuse malignant pleural mesotheliomas (DMPMs) was used in order to determine the differential diagnostic value of immunocytochemical probes against 9 different antigens. While vimentin expression was found in only 50% of cases, regardless of their histological subtype all tumours were found to be cytokeratin-positive when an antibody with broad-spectrum cytokeratin reactivity was used. Conversely, none of the cases was immunostained by antisera against carcinoembryonic antigen (CEA), Leu-M1 antigen, chromogranin, S-100 protein, lysozyme and a T-cell associated antigen. The density of inflammatory cell infiltrates reactive with antisera against the three latter antigens was not associated with the clinical behaviour of the neoplasms examined. Eight DMPM cases showed immunoreactivity with HEA-antibodies against Egp 34, an antigen previously supposed only to be expressed by carcinomas. On the basis of these findings, the consistent cytokeratin reactivity, also of the sarcomatous type of DMPM, may help to exclude metastatic involvement of the pleura by a mesenchymal neoplasm of other origin. CEA and Leu-M1 staining of a given pleural tumour, on the other hand, is indicative of a carcinoma secondarily afflicting the pleura, thus making the diagnosis of primary DMPM unlikely.

Diffuse sclerosing variant of papillary thyroid carcinoma. S-100 protein immunocytochemistry and prognosis

The recently published second edition of the WHO classification of thyroid tumours describes the diffuse sclerosing papillary carcinoma (DSPC) as a specific variant of papillary thyroid cancer (PC). Besides several histological hallmarks, this rare tumour is characterized by its occurrence in young individuals and is thought to have a less favourable prognosis than PC in general. The observations on two examples of this tumour presented herein, however, are at variance at this assumption. The neoplasms occurred in a 10 year old girl and a 34 year old woman. Each time, diffuse involvement of both thyroid lobes and bilateral cervical lymphadenopathy were seen. In one case, the carcinoma extended into the cervical soft tissue. Follow-up disclosed both patients to be without evidence of disease 2 and 13 years, respectively, after thyroid surgery. Immunocytochemically, both thyroid primaries as well as 7 other cases of DSPC reported in the literature showed dense accumulations of S-100 protein positive dendritic/Langerhans cells. Such infiltrations have been demonstrated to be correlated with a benign clinical course of PC. It is thus suggested that DSPC behaves similarly or even less aggressively than PC in general, at least if prominent Langerhans cell infiltration is present.

Prognostic factors in medullary thyroid carcinomas. Survival in relation to age, sex, stage, histology, immunocytochemistry, and DNA content

Patients with medullary thyroid carcinomas (MTC) were analyzed according to age, sex, and tumor stage. In addition, the MTC were screened for the predominant histologic pattern, immunocytochemical spectrum (60 tumors), and DNA content (DNA cytophotometry and DNA flow cytometry, 25 tumors). These findings were correlated with follow-up data available for 45 of these patients. Forty-eight percent of the tumors revealed a polygonal cell pattern, whereas 22% showed spindle-cell predominance. All tumors contained cytokeratin, chromogranin A, and calcitonin (CT). Calcitonin gene-related peptide (CGRP) was present in 92%, carcinoembryonic antigen (CEA) in 77%, neuron-specific enolase (NSE) in 75%, and vimentin in 53% of cases. Positivity for neurotensin, somatostatin, neurofilaments, bombesin, and alpha human chorionic gonadotropin (a-hCG) and serotonin ranged between 3% and 27%. All MTC were negative for substance P, adrenocorticotropic hormone (ACTH), thyroglobulin (TG), or S-100 protein. Local recurrences and regional lymph node metastases revealed identical staining patterns as the primaries. Prognosis of MTC was found not to be related to histologic features (dominant architectural pattern, cellular shape, presence of amyloid deposits) or immunocytochemical pattern. Instead, survival was significantly correlated to age, sex, and stage of disease. The best prognosis was seen in women younger than 40 years and revealing an early stage of disease. DNA measurements added valuable information in assessing the prognosis of MTC.

Quantitative assessment of endogenous testicular and adrenal sex steroids and of steroid metabolizing enzymes in untreated human prostatic cancerous tissue

Total tissue content and subcellular distribution of DHEA sulfate, DHEA, androst-5-ene-3 beta,17 beta-diol, androst-4-ene-3,17-dione, testosterone, 5 alpha-DHT, and 5 alpha-androstane-3 alpha,17 beta-diol as well as the activities of steroid sulfate-sulfatase, 17 beta-hydroxysteroid dehydrogenase, 5 alpha-reductase, 3 alpha/beta-hydroxysteroid dehydrogenase, and creatine kinase were quantified in 12 untreated primary tumors of prostatic cancer. Samples were obtained by radical prostatectomy and serial sections, and were alternately used for either biochemical or morphological evaluation. The results were compared with values determined in benign parts of the same prostates. Qualitatively, all enzymes and steroids found in the benign tissues could also be demonstrated in the cancers. Steroid patterns showed individual quantitative variation but no general differences between the carcinomas and the benign tissues. Enzymes showed a tendency to lower activities in the cancers, particularly when expressed per DNA. Substantial diminutions of creatine kinase and 5 alpha-reductase activity, the latter being often accompanied by an increased testosterone/DHT ratio, were the most striking differences seen in most of the cases between malignant and nonmalignant tissues. Some interesting individual parallels of morphological and biochemical aspects were seen, but there was no obvious general parallelism between the histological picture and endocrinological characteristics.

Androgens, adrenal androgen precursors, and their metabolism in untreated primary tumors and lymph node metastases of human prostatic cancer

Activities of several steroid metabolizing enzymes (steroid sulfate-sulfatase, 17 beta-hydroxysteroid dehydrogenase, 5 alpha-reductase, and 3 alpha beta-hydroxysteroid dehydrogenase) as well as total tissue content and subcellular distribution (nuclear-extranuclear) of several androgen precursors, active androgens, and androgen deactivation products (DHEA sulfate, DHEA, 5-androstenediol, 4-androstenedione, testosterone, DHT, and 3 alpha-androstanediol) were quantified in primary tumors and lymph node metastases of human prostatic cancer obtained from patients without previous endocrine manipulation. Primary tumors were compared to benign parts of the same prostates, and the metastases were compared to their primary tumors. All enzymes and steroids found in benign prostatic tissues could also be detected in the malignant tissues. Even the capacity to accumulate active androgens in the nuclei was found to be unchanged in nearly all of the samples. Lower activities of hormone-dependent enzymes were observed in the cancers, suggesting a less efficient utilization of hormonal stimuli. Most striking changes found in the malignant tissues were a subtotal loss of 5 alpha-reductase activity and a metabolic shift to testosterone, which was more pronounced in samples from metastatic disease as compared to samples from non-metastatic disease. In conclusion, primary tumors and metastases of prostatic cancers not treated by endocrine manipulations retain their androgen receptor system and possess the same capacity to metabolize adrenal androgen precursors along the pathway to DHT as benign prostatic tissue. Consequently, they should be able to use at least androstenedione for production of active androgens directly in the target tissue.

[Occult papillary thyroid carcinoma. Clinical significance and morphology of a common tumor]

In a systematic analysis of surgical specimens of 388 carcinomas of the thyroid 34 occult papillary tumours were revealed. In 18 of the 34 patients cervical lymph-node metastases were demonstrated, which in 16 had been the indication for operation. In 15 patients the tumour was a chance finding in a thyroid resected for other reasons. Postoperative follow-up over an average of ten years demonstrated a uniformly favourable course in all, regardless of tumour size or type, age, sex or lymph-node status. There were no local recurrences or metastases beyond those known at time of thyroidectomy.

Intermediate-filament expression in thyroid gland carcinomas

Paraffin-embedded specimens of 200 primary thyroid carcinomas were examined immunohistologically for the expression of intermediate-filament (IF) protein of the cytokeratin, vimentin and neurofilament type. In 36 cases, snap-frozen tissue was available, and double label immunofluorescence microscopy was performed in 23 of them. Cytokeratin reactivity was found in all cells of all follicular, papillary and medullary carcinoma cases examined. Using a monoclonal vimentin antibody, positive staining was found in many, though not all cells of the papillary tumours and in approximately 50% of the follicular and the medullary carcinomas. Among anaplastic carcinomas, some tumours were positive for cytokeratins, with or without coexpression of vimentin. Neurofilaments could only be demonstrated in approximately 13% of medullary tumours which in general also exhibited vimentin positivity. The differences of IF expression in follicle and C-cell thyroid carcinomas and the broad variation of cytokeratin and vimentin immunoreactivity among anaplastic tumours of this organ is discussed in relation to the possible intrinsic heterogeneity of these tumours and the diagnostic value of these markers.

[Classification, histologic and cytologic grading and regression grading of prostate cancer]

The submitted recommendation of the pathologic- urologic team "prostatic carcinoma" is the result of several meetings, in order to provide a basis for a uniform nomenclature in diagnosis, therapy, and prognosis of prostatic carcinoma to urologists and pathologists in practice.

Ultrastructural observations on the histogenesis of localized fibrous tumours of the pleura (benign mesothelioma)

Five localized fibrous tumours of the pleura (benign mesothelioma) were studied ultrastructurally in order to elucidate their histogenesis. The histological subtypes of this benign fibrous lesion of the visceral pleura, i.e. the cellular, the collagenous, and the hyaline, were separately analysed. The tumours are composed of undifferentiated mesenchymal cells, intermediate and differentiated fibroblasts as well as collagenous interstitial tissue. The varying distribution of these cell elements account for the various histological subtypes. Morphological similarities between the mesenchymal tumour cells and the superficial mesothelial cells, which are always separated from the true tumour tissue by an intact basement membrane, were not observed. The different cellular elements can be regarded as parts of a continuous spectrum of cytodifferentiation, in which the mature fibroblasts are derived via intermediate forms from the undifferentiated cells. It is concluded that the localized fibrous tumours of the pleura arise from immature mesenchymal stem cells, which seems to be normally found in the submesothelial layer of the visceral pleura.

[Flow cytometric determination of DNA distribution patterns of malignant and benign tumors of the prostate (author's transl)]

56 samples of prostates, clinical suspected of being carcinomas, were examined by flow cytometry concerning their DNA distribution patterns. Carcinoma was diagnosed in 25 cases. All histologically benign samples showed a G1-fraction higher than 95%. Accordingly all cases with a G1-fraction lower than or equal to 95% were interpreted to be flow cytometrically positive (= malignant). The results of flow cytometric measurements essentially depend on the relation of the compounds of the sample--carcinomatous and normal tissue. Concerning the DNA distribution pattern, highly differentiated carcinomas do obviously not always differ from normal tissue. Hence they can escape from flow cytometric proof. An improvement of the flow cytometric distinction between histologically malignant and benign samples is achieved by the introduction of correction procedures for background and cell aggregations.

[The incidence of regional lymph node metastases in operable prostatic carcinoma (author's transl)]

Operation specimens of 165 radical prostatectomies were examined systematically for their pathological anatomy. In 22 cases (13.3%) there were metastases in the obturator and (or) iliac lymph nodes, in 12 cases these were micro-metastases with a maximal diameter of 2 mm. Ten were classified as N1, 7 ad N2 and 5 as N4. Lymph node involvement increased with increasing tumour staging: from 10% in T2 to 26.3% in T3. All metastasizing tumours had invaded the capsule (P3), 77% had additional infiltration of the seminal vesicles and in 73% the tumour volume was at least 50% that of the prostate. Thus prostate carcinoma must reach a certain size and penetrate the capsule before lymph node seeding occurs. The rate of metastases increases ninefold when the seminal vesicles are infiltrated. All metastasizing prostate cancers were polymorphic and in 73% the tumour differentiation in the metastases was identical. The findings as regards localisation of the tumour in the prostate and the metastases correlated in 91%. This result leads one to suspect a regular course of laterally localised spread in which the group of obturator lymph nodes appears to lie in the primary lymph drainage area of the prostate. The prognostic significance of regional lymph node metastases cannot yet be evaluated.

[Pathomorphology of the human prostate gland]

The pathologic processes of the adult human prostatic gland, which consist of regressive and atrophic changes as well as of benign hyperplastic, metaplastic, dysplastic and carcinomatous proliferations, are analysed by light and electron microscopy. The examinations give rise to a new concept of the morphogenesis of each separate lesion. The results show the importance of the prostatic basal cell for the development of the special benign and malignant proliferations of the glandular epithelium. The histologically defined different alterations in the human prostatic gland are the results of the various differentiation possibilities of the basal cell.

Carcinoma and dysplastic lesions of the prostate. A histomorphological analysis of 50 total prostatectomies by step-section technique

50 prostate carcinomas which were totally prostatectomized together with removal of the seminal vesicles in all cases and pelvic lymphadenectomy in 38 cases were studied histologically. The material was cut by step-section technique in 5 mm thick slices and "large area slides" were made. 4 of the 50 carcinomas were morphologically circumscribed (stage I), 6 tumors were limited to the organ (stage II) and 40 prostate carcinomas had already penetrated the capsule, i.e. fascia of Denonvillier (stage III). In 12 cases the seminal vesicles were involved, regional lymph node metastases were seen 8 times. The carcinomas were mainly localized in the peripheral part of the organ (28 X in the periphery, 21 X both peripherally and centrally and only 1 X in the centre). Multifocal tumor growth was found in 30 cases (60%). The main mass of tumor was mostly situated in the middle (25 X) and caudal (15 X) zone of the prostate. During the course of tumor growth the expansion was directed centrally but then mainly longitudinal and parallel to the urethra. By progressing tumor volume there was a noticeable increase in capsular penetration as well as infiltration of the seminal vesicles and lymph node metastases. Histologically 10 carcinomas showed a uniform pattern, a unique solid and/or cribriform tumor architecture was never observed. 90% of the pluriform carcinomas consisted of the morphological stage III.

Cyto- and histomorphogenesis of the prostate carcinoma. A comparative light- and electron-microscopic study

The fundamental histologic proliferation patterns of the prostate carcinoma are presented by the glandular and solid and/or cribriform structures. These were ultrastructurally analyzed from 28 carcinomas based on the cell forms in prostate carcinomas, which were already defined by electron microscope. These are characterized by their different cytoplasmic differentiation, whereby the singular cell types each represent a different functional state of a common tumor cell. The results indicate that the prostatic carcinoma develops morphologically in phases. The well-known growth patterns of the tumor are equivalent to its different states of development. In the first phase, a pattern develops out of a tumor stem cell (perhaps "primary atypical reserve cell"), which is either glandular or solid/cribriform, whereas this depends on the trend of the tumor cells to differentiate. The glandular structure possesses centrifugally proliferated glandular, often functionally deranged tumor cells, and shows signs of early stromal infiltration. The solid/cribriform pattern consists of centripetal proliferated, often less-differentiated tumor cells with or without lumen formation, and a peripheral layer of basal cells, whereby the idiopathic stroma architecture remains as it is. In the successive phase, stroma infiltration and destruction is distinctly marked durinaplastic" during tumor growth. Histologically, one often sees at this stage an "anaplastic" pattern; however, ultrastructurally its orign can be recognized as being glandular or solid/cribriform. The advanced stages of the tumor are furthermore characterized by a mixed cell pattern with all states of differentiation and by progressing tumor cell degeneration.

[Ultrastructure and formal pathogenesis of embryonal rhabdomyosarcoma (author's transl)]

An embryonal rhabdomyosarcoma of the nasopharynx of a 10 year old boy is analysed with light and electron microscopy. With regard to cell shape and cytoplasmic features the following four tumour cell types could be distinguished: 1. Undifferentiated mesenchymal cells with a big loosely packed nucleus and a small cytoplasmic rim with only few cell organelles; 2. Undifferentiated tumour cells with a broad cytoplasmic body which contains a dense network of nonspecific intermediate filaments with a diameter of about 100 A; 3. Immature rhabdomyoblasts with randomly orientated specific myofilaments; 4. Fully differentiated rhabdomyoblasts with well developed myofibrils often showing a sarcomeric pattern. Glycogen deposits which were seen in great masses in many tumour cells were regarded to result from degenerative processes within the tumor. The cellular stages in the development of rhabdomyoblasts are basically identical to those known from the embryogenesis and regeneration of striated muscle. From these observations the two following developmental pathways are suggested: 1. Origin of the tumour from an undifferentiated mesenchymal cell; 2. Atypical regeneration of striated muscle which terminates in malignant progressive tumour growth. At present, the body of information about rhabdomyosarcomas supports the assumption of an origin from immature mesenchymal cells. Nevertheless, the second theory cannot be totally excluded.

[Coincidence of Hodgkin's disease and epithelioid-cell granulomatosis in liver and spleen]

Two of seventy patients with Hodgkin's disease who had exploratory laparotomy with liver biopsy and splenectomy were found to have extensive epithelioid-cell granulomas in liver and spleen. The coincidence of malignant tumour and epithelioid-cell granulomas of liver and spleen without lymph-node involvement is unusual. Knowing of the coincidence of Hodgkin's disease and such granulomas is clinically important because extensive diagnostic measures, including biopsy, are necessary in the differential diagnosis, and the patient's prognosis will depend on the therapeutic measures taken.

[Morphological and clinical results after combined hormone and radiation therapy for carcinoma of the prostate (author's transl)]

83 prostatic carcinomas were analysed morphologically and clinically before and after combined therapy. The classification of these tumors is based on the proliferation pattern resulting in a group with only one and a group with a variety of growth patterns. The largest groups were carcinomas with glandular structures. On the basis of multiple biopsies the histologic regression of the tumors was determined. In 71% of the cases there was good agreement of morphological results and local palpation findings. Further analyses revealed a correlation between histological growth pattern of the carcinomas and degree of regression: prostatic carcinomas with glandular pattern showed more often a good regression after combined therapy than solid and(or) cribriform tumors. In the groups with a variety of structural pattern the degree of regression was dependent on the prevailing tumor structure. According to these results the organoid-glandular carcinomas of prostate are prognostically more favourable than all the other proliferation patterns. Nevertheless in a single case a prognosis of the therapeutic effect based only on the tumor differentiation can not be made.

[Morphology and clinical significance of the meningeal hemangiopericytoma (author's transl)]

Hemangiopericytomas of the meninges are rare tumors. Three tumors of this type with a course over more than 10 years each are reported. All three tumors were primary diagnosed as meningiomas (one: vascular, two angioblastic). The diagnosis was changed to hemangiopericytoma only then when recurrences and extracranial metastases had occurred. Morphologically, "angioblastic meningioma" and "hemangiopericytoma of the meninges" show striking common features. The principal pattern bases on the blastomatous increase of capillary blood vessels lined by a normal endothelium, extracapillary proliferation of pericyte-like mesenchymal cells and an intercellular network of reticulin fibres. Light- and electron microsopic findings do not demonstrate the characteristics of a meningioma. Furthermore, clinical data and growth pattern of "angioblastic meningioma" and "hemangiopericytoma of the meninges" are well comparable. Therefore, it seems to be justified to interpret these tumors as a tumor entity with identical histogenesis. It is well known that hemangiopericytomas frequently recur and metastasise. On the other hand, meningiomas are usually benign. For those reasons we suggest that these tumors should be uniformly classified as "hemangiopericytoma of the meninges" in order to stress the significance of these particular tumors of the meninges regarding their treatment and behaviour.

[Morphogenesis and significance of epithelial metaplasia in the human prostate gland. An electron-microscopic study (author's transl)]

Electron-microscopic studies were done to point out the morphogenesis of transitional and squamous epithelial metaplasia in the human prostate gland. The basis of epithelial metaplasia is a multi-layered proliferation of the basal cells and subsequent divergent differentiation. Transitional metaplasia can be viewed under the light microscope; the electron microscope on the other hand does not show all structural features of the transitional epithelium, such as: The cover cells of the metaplastic epithelium, which do not reach the basement membrane; the surface cells, which are always mononuclear and show signs of beginning adenoid differentiation. Extreme twisting of the lateral cell membranes as a morphological equivalent of deformability was not observed. Squamous epithelial metaplasia, contrary to transitional epithelial metaplasia, shows the criterions true characteristics of squamous epithelium at both the light and electron microscopic levels: The metaplastic cells have an abundant cytoplasm containing the characteristic structures with numerous tonofibrils and broad desmosomes. Microvilli-like processes of the cytoplasm project into the lacunar interfacial canals. In addition aggregates of glycogen granules and deposits of osmiophilic material can be seen, representing the first step of keratinization. Epithelial metaplasias in the prostate occur not only in the central area near the urethra, but also in the peripheral ducts and glandular acini. An estrogen-androgen imbalance is suggested to be an essential factor in the etiology of prostatic epithelial metaplasia. A reversibility of squamous epithelial metaplasia is unlikely. To our knowledge, the epithelial metaplasias in the prostate do not represent a precancerous lesion.

[Ultrastructural findings in carcinoma of the prostate after combined endocrine and radiation treatment]

Carcinomas of the prostate treated by orchiectomy, 60Co-radiation, and hormonal drugs a relatively short time prior to the time of biopsy were studied with the electron microscope. The following degenerative changes of tumor cells and fibromuscular stroma were found: The nuclei of the tumor cells were intensely heterochromatic, irregularly shaped, and the perinuclear rim dilated; large atypical sizes, multiple segmentations and "nuclear invaginations" were observed. The tumor cell cytoplasm showed vacuolar degeneration, and the limiting membranes of the tumor cells were extensively destroyed. Remarkable changes were also found in the fibromuscular stroma: There was a proliferation of collagenous fibers as well as degenerative transformations ending in hyalinization. The smooth muscle cells were dissociated and fragmented, sometimes showing vacuolar degeneration of the cytoplasm. The endothelium of the blood vessels was swollen, and the vessel walls were thickened. In spite of these radiation-induced lesions it remains undecided as to what degree the other therapeutic measures take part in the total therapeutic effects as seen in the ultrastructural findings. However, these regressive changes are much more pronounced than those seen after orchiectomy alone and partly resemble the findings which are characteristic of radiation induced structural lesions. The morphological changes are not uniform throughout the tumor. It is not unusual to find intact tumor cells next to totally degenerated cells. They represent poorly differentiated tumor cells. It is discussed whether these "embryonic" tumor cell types are and remain resistant to treatment and if a tumor recurrance may originate in them later on.