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Biomedical subjects

C Sigg

Publications and source records attributed to C Sigg.

At least 37 records · Page 2Linked to original sources
PubMed1988

[Multiple primary melanomas of the hair follicles--a special form of malignant melanoma of the skin].

Within 5 years, a 79-year-old male patient developed multiple primary melanomas, all which originated from the hair follicles. The fact that this patient was elderly, the high number of primary tumors, their follicular origin, and the lack of a history of such disorders in the patient's family caused us to postulate that multiple primary follicular melanomas represent a special form of malignant melanoma of the skin.

Aged↗
PubMed1988

[Andrologic studies in patients with X-chromosome recessive ichthyosis].

In the past there have been several reports of testicular abnormalities (hypogonadism, cryptorchidism and so-called atypical germ cells) in patients with recessive X-linked ichthyosis. Anamnestic interviews, clinical as well as chemical investigations in ten patients (aged 25-52 years) with recessive X-linked ichthyosis have been undertaken in order to examine their endocrine and exocrine testicular function. Normal serum levels of gonadotropins were observed in nine of ten patients, while four of ten men had decreased levels of dehydroepiandrosterone. In addition, in eight of these ten patients spermatological alterations were found: two patients suffered from oligozoospermia, while asthenozzospermia occurred in seven patients and teratozoospermia was registered in three men. Although andrological abnormalities were found in five out of ten patients (cryptorchidism, varicocele), the high incidence of spermatological alterations is remarkable. Further investigations will be necessary to clarify whether steroid sulphatase is responsible for some of these alterations, especially for the pronounced asthenozoospermia.

Adult↗
PubMed1987

[Is testicular biopsy still a current andrologic study method?].

In the course of decades, the indications for testicular biopsy have significantly changed with the development of hormone estimation and chromosomal analysis. Today modern andrological techniques may replace the biopsy in many cases. On the basis of an exactly defined history and thorough clinical, spermatological, and endocrinological investigations, however, there may be some situations which call for a testicular biopsy in order to settle questions still unclear in the evaluation of male infertility. In addition, modern techniques allow exact histological and cytological evaluation. Therefore, histological examination of testicular tissue is frequently of prognostic value. Besides the andrological indications, the increased incidence rate of so-called atypical germ cells in testicles of infertile men represents an additional oncological indication for testicular biopsy.

Biopsy↗
PubMed1987

[Congenital nevus cell nevi as precursors of melanomas of the skin].

Based on our observations in 25 patients and on the literature of the last few years, we comment on the clinical findings, genetics, histology, ultrastructure, malignant degeneration and therapy of congenital nevocytic nevi. The differences between large and medium-sized nevi are emphasized.

Cell Transformation, Neoplastic↗
PubMed1987

[Congenital nevus cell nevi of the skin--a nomenclatural and therapeutic problem].

The alarming increase in the incidence of malignant melanomas has caused interest to be focused on some of the precursors or tumor markers, such as dysplastic nevi or congenital nevocytic nevi. Both clinically and histologically, as well as by the incidence of malignancy, three groups of congenital nevocytic nevi may be distinguished. Small nevi (diameter less than 1.5 cm) are frequent, but it remains to be elucidated whether they involve an increased risk of malignancy. On the basis of differences in potential malignancy the larger congenital nevocytic nevi may be subdivided into two forms. Malignant melanomas occur more frequently and earlier in life in large nevi (diameter greater than 20 cm) compared with medium-sized nevi (diameter 1.5-20 cm). Medium-sized congenital nevi can usually be removed without considerable problems. In very large nevi, however, surgical treatment is more difficult. Since the risks involved in performing radical surgery in children may bear no relationship to possible benefits, repeated clinical examinations, detailed photographic documentation and immediate excision of any suspicious skin areas must be undertaken in such patients.

Humans↗
PubMed1985

The significance of giant cells in human testicular seminomas. A clinico-pathological study.

In order to study the nature and significance of various giant cells encountered in seminomatous tumors of the testis, we reviewed the morphology of 243 consecutive pure seminomas and 107 combined (mixed) tumors, as well as the long term clinical follow-up in 26 patients. Giant cells were grouped into histiocytic or neoplastic ones and the latter subtyped according to morphologic and immunocytochemical characteristics. Neoplastic giant cells were found in 34.6% of all pure seminomas and in 11.2% of all combined tumors, i.e. twice as often as histiocytic giant cells in either tumor group. The various types of neoplastic giant cells were found alone or in combinations with other types. Giant cells capable of elaborating B-HCG were seen in 19.3% of all pure seminomas and in 9.3% of seminomatous components of combined tumors. These incidences argue strongly against a trophoblastic element infiltrating a seminoma from a concomitant occult choriocarcinomatous focus. Large mononuclear giant cells, seen in spermatocytic seminomas, were observed in 15.6% of all pure seminomas, particularly in combination with B-HCG producing giant cells. Another type, characterized by marginated nuclei and eosinophilic cytoplasm were invariably part of a mononuclear cell population of similar features and encountered focally in 9.1% of all pure seminomas. Clinical follow-up, particularly in cases with B-HCG positive giant cells, revealed that treatment as for conventional seminomas at an early stage at least is followed by an excellent course.

Cell Nucleus↗
PubMed1985

[Increased desquamation of immature germ cells in the ejaculate of infertile men].

In order to find indications of underlying disorders, clinical, hormonal and spermatological examinations were conducted on 21 infertile male patients, who had shown increased exfoliation of immature germ cells in the ejaculate. However, no significant anamnestic, clinical or hormonal data were obtained. The differential spermiogram, on the other hand, revealed more or less uniform oligo-astheno-teratozoospermia, which was also characterized by frequent alteration of the middle and end pieces of the spermatozoa. In 11 of 21 patients, Ureaplasma urealyticum was demonstrated in the seminal plasma. Examination of the cellular fraction in the seminal fluid by impulse cytophotometry revealed a slight rise in the hyperhaploid peaks, a definite increase in the diploid peaks, and pronounced increase in the hypohaploid peaks. It remains debatable whether the hypohaploid peaks represent a karyolysis of exfoliated immature germ cells, an idiopathic decrease in the DNA content of sperm cells, an artificial fragmentation, or increased disintegration of spermatozoa. The frequency of seminal infections with U. urealyticum raises the question of whether or not the increased exfoliation of immature germ cells represents a specific alteration of the sperm cell precoursers.

Adult↗
PubMed1984

[Morphometric and histologic studies of testicular biopsies in obstructive azoospermia].

271 testicular biopsies from patients with obstructive azoospermia and near normal germinal epithelium were investigated morphologically and/or histologically in a search for lesions due to obstruction. 529 testicular biopsies from patients with oligozoospermia and 50 testicles examined post mortem served as histological control. The morphometric data of the seminiferous tubules in cases of obstructive azoospermia were within the standard range determined histologically in normal controls. In 13.3% of cases with obstructive azoospermia and in 6.8% of patients with oligozoospermia, however, testicular biopsies revealed a remarkably constant lesion, i.e. groups of seminiferous tubules with ectasia and atrophy, densely packed and usually surrounded by some fibrotic tubules. The etiology of this lesion remains unclear, but it may represent acute focal atrophy of germinal epithelium due to obstruction by the adjacent fibrotic tubules.

Adult↗
PubMed1984

Atypical germ cells of the testis. Comparative ultrastructural and immunohistochemical investigations.

It is uncertain whether the so called intratubular atypical germ cells (carcinoma in situ cells) demonstrable in the testicular tissue around different germ cell tumors and in testicular biopsies of patients with impaired fertility are identical with regard to their morphology and further development. Thus atypical germ cells of 18 patients with testicular germ cell tumors and of 3 patients with atypical germ cells in testicular biopsies without tumor were studied by electron microscopy and/or by immunohistochemistry. The atypical germ cells show characteristic alterations distinguishing them from normal germ cells, especially spermatogonia. However, there are no differences between atypical germ cells in the above mentioned groups. Immunohistochemical reactions are negative with anti-alpha-fetoprotein and anti-beta-human-chorionic-gonadotropin, but 6 of the 15 cases are positive with antiferritin. However, this positive reaction occurs in cases in different diagnostic groups. Atypical germ cells of the different groups cannot be distinguished by electron microscopy or immunohistochemical methods, but further investigations, including cell cultures, may provide more information.

Adult↗
PubMed1983

[Morphology of the adrenal gland in primary hyperaldosteronism].

Between 1964 and 1980 25 patients (16 women and 9 men) underwent unilateral adrenalectomy for primary hyperaldosteronism at the Zurich University Hospital Department of Urology. In 17 cases (68%) review of the histological slides revealed adenoma, in 3 cases (12%) so-called idiopathic hyperplasia, and in one patient (4%) adrenal carcinoma. The histological features of these 21 cases were in keeping with the postoperative changes in blood pressure. However, in 4 patients (16%) the alterations of adrenal tissue could not be either correlated with the subsequent clinical course or satisfactorily classified without electron-microscopic and biochemical examination.

Adenoma↗
PubMed1983

The frequency and morphology of "giant spermatogonia" in the human testis.

Giant spermatogonia (GS) characteristically appear singly between their normal counterparts. Their cytoplasm is clear by light microscopy and their ovoid nuclei, measuring at least 13 micron in diameter, contain homogeneously distributed chromatin. These cells were described originally in the last century and were interpreted as isolated physiological giant cells of the sexual epithelium (Stieve 1930). In our own study we found GS in the normal testis at an average frequency of 0.65/50 tubules. GS occur at the same frequency in testicular tissue surrounding germ cell tumors and in biopsy specimens from men with impaired fertility, except in the so-called mixed atrophy of the testis where increased numbers of GS per tubule are found. Ultrastructurally, GS are distinguishable from normal spermatogonia, from atypical germ cells and from seminoma cells. In addition, we found several distinct ultrastructural differences between GS and cells of pre-spermatogenesis as reviewed in the literature.

Atrophy↗
PubMed1983

[Light and electron microscopy of primary localized cutaneous amyloidosis].

The two polar types of primary cutaneous amyloidosis are characterized by different alterations of the epidermis, i.e., epidermal hyperplasia and hyperkeratosis in lichen amyloidosus, hyperpigmentation without any essential epidermal changes in macular pigmented amyloidosis. Biopsies from six patients suffering from lichen amyloidosus and macular pigmented amyloidosis were examined light- and electron-microscopically to provide any information that could account for the different epidermal behavior in these two polar forms of primary cutaneous amyloidosis. No ultrastructural alterations were found that could be regarded as pathognomonic for one or the other form. Although in lichen amyloidosus alterations on keratinocytes seemed to be more pronounced than in macular pigmented amyloidosis, which, in contrast, shows stronger alterations of the basal membrane and the pigmentary system, these findings do not satisfactorily elucidate the histological and clinical differences between these most frequently occurring representatives of primary cutaneous amyloidosis.

Adult↗
PubMed1982

[Light and electron microscopic and cytophotometric investigations in multiple Bowenoid papules (author's transl)].

In to find a satisfactory nosological position of so-called Bowenoid Papules, biopsies of three patients were examined by light- and electron microscopy order as well as by cytophotometry and the findings were compared to the results of two cases of Bowen's disease. The dysplasia of the epidermis, hardly definable from Bowen's disease by light microscopy, revealed numerous ultrastructural alterations which also can be observed in the intraepidermal carcinoma, in addition single alterations indicate a viral genesis (which couldn't be proved until now). Cytophotometric investigations showed an only slight increase of DNA in the nuclei. It is interesting, however, that biopsies of a recurrent Bowenoid Papulosis exhibited a distinct increase of the DNA content. The not aggressive postoperative behaviour of two cases faces a third case with advanced dysplasia (increased DNA-content) and recurrence. The origin and/or the releasing moments for this diverging behaviour are not quite clear yet.

Adult↗
PubMed1981

Vasoseminal vesiculography before and after ejaculation.

Vasoseminal vesiculographies before and after ejaculation were compared in 16 cases of male sterility. In 12 cases the contrast medium was excreted into the ejaculate and the contours of the seminal vesicles were contracted after ejaculation. In 4 cases, however, there was little or no contraction of the seminal vesicles. Here the seminal tracts were considered to be abnormal and this dysfunction seems to be the cause or at least one of the cofactors responsible for sterility. The degree of excretion of contrast medium into the ejaculate seems to depend on the function of the seminal tract. Therefore, a postejaculation seminal vesiculogram is useful as a parameter for estimating the function of the seminal tract.

Adult↗