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L D Leder

Publications and source records attributed to L D Leder.

At least 73 records · Page 4Linked to original sources
PubMed1985

[DNA content of lymphocytes and mononuclear tumor cells in Hodgkin's disease].

Thirteen lymph node biopsy specimens with Hodgkin's disease (six cases of the nodular sclerosis type; six cases of the mixed cellularity type; one case of the lymphocytic depletion type) were studied with scanning cytophotometric measurements. The DNA content of small lymphocytes, large lymphocytes, atypical mononuclear cells and Hodgkin cells was measured. The sizes of the nuclei and mitotic indices were also measured. There were no lymphocytes with aneuploid DNA stemlines. Large lymphocytes showed proliferative activity which is possibly reactive, although its neoplastic character cannot be excluded. Hodgkin cells exhibited aneuploid values in seven cases and atypical mononuclear cells in only four cases. The nuclear sizes and the DNA content of the atypical mononuclear cells ranged between the values of lymphocytes and Hodgkin cells. The mixed cellularity type showed higher DNA values, more frequently occurrence of aneuploid stemlines and a higher frequency of mitotic figures than did the nodular sclerosis type. The results confirm the different grades of malignancy of the various histopathological categories of Hodgkin's disease.

Biopsy↗
PubMed1985

The cytochemical demonstration of cyanide resistant peroxidase does not identify eosinophils selectively.

Potassium cyanide (KCN) resistant peroxidase is generally accepted by hematologists as a selective stain for the eosinophilic cell line. However, it has been demonstrated biochemically that not only the peroxidases of neutrophils but also those of eosinophils can be inhibited by KCN. Therefore, bone marrow smears of hematologically normal patients were subjected to the peroxidase reaction in the presence of varying concentrations of KCN. It was found that with increasing concentrations of KCN not only neutrophils but also eosinophils were inhibited. Moreover, there were always neutrophilic promyelocytes that were still positive when a considerable number of the eosinophils was already inhibited. Therefore, it can be concluded from our results as well as from biochemical data that there is no concentration of KCN which demonstrates the total of the eosinophilic cell line selectively. The implications of these findings are discussed.

Eosinophils↗
PubMed1985

Adenocarcinoma of the colon with syncytiotrophoblastic differentiation: differential diagnosis and implications.

A case of adenocarcinoma of the colon is reported, whose metastases exhibited a syncytiotrophoblastic differentiation that gradually increased with advancing distance from the primary. Immunohistochemically, syncytiotrophoblastic giant cells with strong positivity for beta-HCG could be demonstrated within the metastatic tissue. Also, there was beta-HCG positivity in a fraction of the atypical epithelial elements of the primary. The case is discussed with respect to the differential diagnosis, and the cause of the syncytiotrophoblastic differentiation is attributed to the phenomenon of genetic instability. The case shows that by virtue of genetic instability totally new differentiations may be elaborated, so that the phenotypical appearance of a given tumor does not necessarily allow conclusions as to its tissue of origin. Thus, observations such as the one presented here clearly indicate that the histogenetic principle of tumor classifications by far does not apply to all cancers and that, therefore, its value and validity are considerably limited.

Adenocarcinoma↗
PubMed1983

[On the concept of "specificity" in morphological diagnosis].

The present paper deals with the term specificity. The term is analyzed with respect to its linguistic deduction, as well as its mode of application to morphological objects. We come to the conclusion that specificity is not an absolute but rather a relative term, since it is graduable. Its meaning largely depends on the conditions under which it is applied to morphological objects. When applied to morphological criteria, the term specificity is concerned in most cases with differential diagnosis; it rarely refers to diagnosis. In other words: Under certain circumstances, specific criteria may be absolute and, therefore, proving, but usually they have merely a relative meaning in the sense of indicating and delineating.

Diagnosis↗
PubMed1983

[Pathology of the most common malignant soft tissue tumors].

The present article provides an overview on the main pathological criteria of the most frequent malignant soft tissue tumors. Although these malignancies are only rarely observed and amount only to approximately 1% of all malignancies, their exact morphological analysis is of importance, because different therapeutical consequences may be drawn depending on the kind of the tumor and its grade of malignancy. Also, the prognosis of soft tissue sarcomas is extremely variable but is related to the morphology. Therefore, soft tissue sarcomas should be investigated very individually. Proper information of the pathologist by the clinician of each given case is necessary for a proper histological evaluation of biopsies that must be representative. It is recommended, whenever possible to excise the total of the tumor. With regard to these aspects liposarcomas, malignant fibrous histiocytomas, rhabdomyosarcomas, leiomyosarcomas, synovial sarcomas, malignant mesenchymomas, angiosarcomas, and fibrosarcomas are discussed, and their essential properties are reported.

Fibrosarcoma↗
PubMed1983

[Pseudofollicles in chronic lymphatic leukemia].

In chronic lymphatic leukemia lymph nodes show very often nodular aggregates of cells that are somewhat larger than small lymphocytes and that are less hyperchromatic and less closely packed. These aggregates appear histologically as light areas that are called pseudofollicles, pseudonodules or proliferation centers. However, it has not been substantiated as yet that a more active proliferation of cells indeed takes place within these areas. Therefore, in 10 cases of chronic lymphatic leukemia the DNA-content, the size of the nuclei, and the frequency of mitoses within and outside the pseudofollicles were assessed. It could be shown that the cells of the pseudofollicles are indeed more actively proliferating populations than the cells outside the pseudofollicles. This proves that pseudofollicles are proliferation centers.

Cell Nucleus↗
PubMed1983

[Some pathologico-anatomic substrates of hypertensive lesions].

After some introductory remarks on the definition of the various forms of hypertension, a short description of the changes in arterial vessels associated with hypertension is given. Hypertension is by no means a prerequisite for atherosclerosis and arteriolosclerosis, but hypertension enhances such vascular changes. In malignant hypertension, typical fibrinoid arteriolonecroses occur. Hypertension leads to hypertrophy of the left ventricle through enlargement of individual muscle fibres, but numeric hyperplasia also occurs. At the same time, coronary atherosclerosis may be aggravated by systemic hypertension. Hypertrophy together with coronary sclerosis may result in various forms of ischemic heart disease among which myocardial infarction and its complications are the most important ones. There are intimate mutual interactions between hypertension and ischemic renal damages, the most important of which are briefly discussed. Again, many of these changes do not necessarily require hypertension as a prerequisite. Massive haemorrhage into the substance of the brain is usually associated with systemic arterial hypertension, but requires predisposing atherosclerosis and arteriolosclerosis: Walls of healthy arteries do not give way, however high the blood pressure may be.

Arteries↗
PubMed1982

[Bone marrow transplantation for aplastic anaemia and acute leukaemia (author's transl)].

Twenty-six bone marrow transplantations were performed at the West Germany Tumour Centre at Essen between December 1975 and December 1981. Three patients had aplastic anaemia, 23 acute leukaemia. Of the leukaemia patients 13 had a recurrence and ten were in full remission at the time of the transplantation. Two of the patients with a recurrence received deep-frozen autologous marrow from the remission phase. One patient with aplastic anaemia had an identical twin as donour, while all other patients received allogeneic marrow from histocompatible family members. Eleven patients are still alive, all three of those with aplastic anaemia, one of those with leukaemia in a recurrence, and seven of those with acute leukaemia in full remission. Two of the survivors have a chronic graft-host reaction, but the others are symptom-free, after an observation period of up to four years. Main causes of death were leukemic recurrence (6), infection (5), and graft-host reaction (2). It would seem that at present bone marrow transplantation offers the best chance of a cure for severe aplastic anaemic and acute leukaemia in adults, but only if transplantation is undertaken early and not in the end-stage of the disease.

Acute Disease↗
PubMed1981

[On the concept of semimalignancy from the standpoint of general tumor pathology].

In the past, the term "semimalignancy" had been applied to a heterogeneous group of tumours, namely to tumours of a low grade of malignancy, to tumours of an equivocal dignity and even to benign lesions. Furthermore, the term as such is highly ambiguous. This is discussed in the light of theoretical considerations and of suitable examples. It is suggested not to apply the term "semimalignancy" any longer.

Adenoma↗
PubMed1980

Myeloma with immunohistochemically different cell populations: implication for the validity of immunohistochemical assessment of lymphoma cell monoclonality.

A case of myeloma showed histologically a monotonous pattern of relatively mature myeloma cells and an IgG-kappa paraproteinemia. In contrast to ordinary stains, the immunoperoxidase reactions for kappa and gamma gave inhomogeneous results. Light and heavy chains were formed by clusters of different subpopulations of myeloma cells. Serial sections showed that kappa-positive clusters were gamma-negative and vice versa. Thus, this morphologically homogeneous myeloma turned out to be immunohistochemically heterogeneous. We assume that two subpopulations have developed that produced separately kappa- and gamma-chains. Therefore, these chains might have been circulating separately and not as complete IgG-kappa molecules. Guided by our findings, the results of other investigators are discussed. Some considerations on the validity of immunohistochemical demonstration of tumor cell monoclonality are given implicating the diagnostic equivocation of immunohistochemistry for non-Hodgkin's lymphomas, especially for so-called "immunocytomas".

Aged↗
PubMed1980

[Pathologic-anatomic reflections on portal hypertension (author's transl)].

Portal hypertension is defined as an increase of the portal venous pressure over 20 cm H2O or 7 mm Hg, respectively. It may be induced by different types of portal venous stenosis or obstruction, primarily by cirrhosis and fibrosis of the liver and, less frequent by posthepatic disorders such as the Budd-Chiari-syndrome or congestive heart failure. Portal hypertension is followed by ectasia and phlebosclerosis of the portal vein, by splenomegaly, ascites and by various types of collateral circulation. Among these, oesophageal varices, are most important since they often lead to acute upper gastrointestinal haemorrhage, the major complication of portal hypertension. Bleeding from oesophaeal varices is essentially based on atrophy of the squamous epithelium, caused by ischemia from local hypoxia and venous stasis. Portal hypertension and the frequently compromised blood clotting mechanism due to reduced synthesis of clotting factors in the liver aggravate the bleeding. Atrophy of the esophageal mucosa presents an area of decreased resistance likely to ulcerate with easy erosion of the varices--usually lying very superficially--; with mechanical irritation by food or peptic erosion from gastroesophageal reflux being frequent inducers of hemorrhage.

Budd-Chiari Syndrome↗
PubMed1980

[Angioimmunoblastic lymphadenopathy. Evolution into malignant lymphoma (author's transl)].

In the last years angioimmunoblastic lymphadenopathy (AIL) was interpreted mainly as a benign reactive lymphnode disease. Recently, the reports about a progression into malignant lymphomas have become more numerous. We present a case of a 74-years-old woman which was diagnosed as lymphogranulomatosis X at first. Four weeks later criteria of malignancy were evident. 7 months after beginning of the disease the patient died. Histological, cytochemical, cytophotometrical, electron microscopical and immunological findings are reported. With regard to the diagnosis AIL it must be kept in mind that an evolution into malignant lymphoma is not infrequent. Hereby obviously a variable differentiation can be expected.

Aged↗