Sural nerve biopsy findings in leprosy: a qualitative and quantitative light and electron microscope study in 4 treated cases of the lepromatous spectrum.

Reports on biopsy findings in multifascicular nerves in lepromatous leprosy (LL) are rare and detailed morphometrical data are not available. In a case of early LL with normal electrodiagnostic findings in sural nerve, the present study revealed marked segmental de- and remyelination concomitant with the sequelae of considerable Wallerian degeneration of preferentially small myelinated fibers (MF) in spite of a normal number/nerve and density/mm2. Segmental de- and remyelination of several consecutive internodes in teased fibers suggests continuous bacterial spread via Schwann cells. In 2 more advanced LL-cases, nervous parenchyme was severely reduced, in a borderline lepromatous (BL) case obviously in part caused by cell infiltrates and granulomata. Distinct fascicle differences in MF-involvement were demonstrated by coefficients of variation of MF/mm2 and teased fiber preparations in LL, consistent with the hypothesis of initial focal spread of bacteria. Numbers and densities of endoneurial vessels were increased only in the later stages of LL. Enlargement of endoneurial area, due to different factors, was encountered except for the most severe LL-case with extensive endoneurial collagenization. Morphometric results were compared with those of other neuropathies. Intact and degenerating bacteria mostly in phagosomes of Schwann cells associated with unmyelinated axons and in macrophages were seen only in the early LL- and the BL-case. Sparse mononuclear cell infiltrates and small focal necrosis, present even in LL-cases, underline the complex pathogenesis of nerve fiber involvement.

Myelinated and unmyelinated fibers in sural nerve biopsy of a case with lepromatous leprosy--a quantitative approach.

A 64-year-old Cambodian male with lepromatous leprosy of several months' duration, with only brief previous treatment, had symmetrical patchy loss of pain and thermal sensibility including the lateral foot regions. Quantitative assessment by light and electron microscopy revealed normal counts of myelinated fibers (MF) and an increased number of unmyelinated fibers (UF). The respective abnormal histograms and the qualitative differentiation of UF-associated Schwann cells suggested a combination of segmental demyelination with Wallerian degeneration of MF, and a loss of genuine UF, concomitant with considerable regenerative activity of both fiber populations.

[Mucinosis follicularis. Histologic and electron microscopy studies]. / Mucinosis follicularis. Histologische und elektronenmikroskopische Untersuchungen.

We studied a case of idiopathic mucinosis follicularis which persisted for 7 months. Histologically, the strong pathological changes began within the sebaceous glands and secondarily occurred in other parts of the pilosebaceous unit. We could demonstrate by electron microscopy that all the follicular cells in this process were undifferentiated sebaceous cells. Therefore, we think that the pathogenesis of mucinosis follicularis originates from a disturbance in the differentiation process of sebaceous cells.

Free subepidermal grenz zone (band of Unna) in lepromatous leprosy. Histological and ultrastructural findings.

Although the grenz zone is indeed free of typical leprosy cells with giant lysosomes, it is not free from leprosy bacilli--these are found in slightly infested macrophages and fibroblasts. For that reason, it would be much clearer if we simply called this region the subepidermal grenz zone of lepromatous leprosy. The subepidermal grenz zone is not pathognomonic of leprosy since grenz zones can be found in other diseases as well. Whereas the grenz zone is typical in lepromatous leprosy, it is not necessarily characteristic of the borderline or the tuberculoid form of the disease. The light and electron microscopical structure of the grenz zone shows that the formation of the subepidermal grenz zone cannot be explained by any particular pathogenetic principle on which therapy can be based.

[Treponema pallidum or Spirochaeta pallida?]. / Treponema pallidum oder Spirochaeta pallida?

First Schaudinn and Hoffmann named the causative organism of syphilis Spirochaeta pallida. Short time later Schaudinn proposed the name Treponema. He mentioned it in a letter of October 14, 1905 to Hoffmann. He supposed that this germ may be a flagellate. This was not correct. The electron-microscopic investigations revealed that this idea did not concur. Therefore it is better to call them Spirochaeta pallida and not Treponema pallidum any more.

Langerhans cells in granulomatous syphilis.

In a case of granulomatous syphilis (transitional state between early and late syphilis), several Langerhans cells (LC) were present in the basal and medial part of the epidermis. Evidence of LC activation was given by the presence of many Langerhans granules, vesicles, a large Golgi apparatus and, sometimes, Golgi complexes. In some LC, signs of degeneration were visible. Langerhans granules surrounded by cytoplasmic material were present in the intercellular space of the epidermis. Apposition of lymphocytes to LC in the dermal space supports the role of LC in immunologic mechanisms. This was further confirmed by signs of phagocytosis in LC. The interaction of LC with intra-epidermal microorganisms (as, for instance, the Treponema pallidum) might be important in the development of the epidermotropic infiltration. This mainly consists of lymphocytes, which sometimes form a pseudolymphoma. A correlation between LC and granuloma formation is suggested.

Electron-microscopic study of the development of the periarteriolar zone in splenic white pulp of rats.

To obtain more information concerning the origin of interdigitating cells, the postnatal development and morphology of the periarteriolar lymphatic sheath in splenic white pulp of rats was investigated by light- and electron-microscopy. Special attention was paid to the ontogeny of interdigitating cells. The spleens of the animals were studied in the age range from 1 h to 28 days after birth. The splenic white pulp of neonatal rats consists only of a few reticuloblasts, which are concentrically arranged around central arterioles. After 21 h an increase in promonocytes and monocytes was noted. Between the fifth and seventh postnatal day monocytogenic cells with a light and almost translucent cytoplasm appear, which display long cytoplasmic projections between the adjacent cells. Neighbouring lymphocytes often insert finger-like processes into the invaginated cellular membrane of these transitional forms. This intimate cellular contact is supported by zonulae occludentes. These cells represent transitional forms between monocytes and interdigitating cells. From seven days of age onwards typical interdigitating cells were present as in adult animals. After the differentiation into an inner and outer periarteriolar lymphatic sheath, the T-cell-dependent area of splenic white pulp has attained its adult appearance and further changes are not to be expected. On the basis of these findings, it is highly probable that interdigitating cells develop via transformation of monocytes.

[High-grade malignant mycosis fungoides with cytological transformation (author's transl)]. / Mycosis fongoïde à forte malignité avec transformation cytologique.

In the Kiel-classification of non-Hodgkin lymphomas a distinction is made between low and high grade malignancy. Mycosis fungoides is listed among the low grade malignant lymphomas because in the cellular infiltrate small lymphoid cells are predominant. Two cases are reported in which the cellular infiltrate of the cutaneous lesions consists mostly of large lymphoid cells resembling lymphoblasts and immunoblasts indicating a high grade malignancy. This type of cellular infiltrate appeared as a blastic transformation from mycosis fungoides very early in one case and at a later stage in another. Clinically these two cases were characterized by a rapid progression leading to the deaths of the patients. The cytological analysis in cutaneous lesions of mycosis fungoides seems to have a prognostical and possibly a therapeutical bearing.

[Internal findings in mastocytosis]. / Interne Befunde bei Mastozytose.

45 patients with urticaria pigmentosa were thoroughly investigated and a systemic involvement concerning the bone marrow, the skeletal system, liver, spleen, and coagulation was often encountered. This systemization is no sign of malignancy. Benign systemic mastocytosis should be differentiated from malignant mastcell-reticulosis.

Nuclear inclusions of tonofilaments and keratohyalin granules in the condyloma acuminatum.

Electron-microscopic investigations of the condyloma acuminatum show different nuclear inclusions in keratinocytes of the granular layer or the layer immediately below. Fibrous structures were indentified as tonofilaments and irregularly shaped electron-dense substances as keratohyalin. However the question remains as to whether there is a connection between the viral infection and the occurrence of such intranuclear inclusions.

[Trichophyton mentagrophytes var. erinacei infection contracted from a hedgehog]. / Trichophyton-mentagrophytes-var.-erinacei-Infektion vom Igel.

Occasionally the hedgehog (Erinaceus europaeus) is infected by Trichophyton mentagrophytes (Robin) Blanchard var. erinacei. This zoophilic dermatophyte may cause a difficult human phlegmatic trichophytia infection. The thread-fungus grows on the usual culture-medium with a clear-white surface without radius-folding. The lower surface of the culture shows a typical brillant-yellow colour. Microscopically the fungus presents abundant microconidia formation and a few distinct macroconidia. Cross-breeding with the tester strain Arthroderma simii "+" was negative, with "-" showed an increased growth and a formation of cleistothecium-primordia in the combination zone.

[Electron microscopic examination of the morphogenesis of the elastic fibre in elastosis senilis and pseudoxanthoma elasticum (author's transl)]. / Elektronenmikroskopische Untersuchungen zur Morphogenese elastischer Fasern bei der senilen Elastose und dem Pseudoxanthoma elasticum.

We undertook to investigate the elastic and collagenous fibers of senile elastosis (s.E.) and pseudoxanthoma elasticum (P.e.). This was done by comparing the above with normal skin under the electron microscope. The main difference is the increasing occurance of a fine granular-filamentous substance composed of microfibrils of varying thicknesses. A new formation arises as this substance is excreted by the activated fibroblasts and the combines extracellulary with the pathological elastic fibers. In the case of P.e. there is an additional calcification. It seems that with the elastogenesis of s.E. small elastic fibers are formed. P.e., in contrast, shows irregular electron-dense reticular sheets with numerous holes. The alteration of collagen observed in both diseases is considered as the primary change (which arises in both cases through the fine granular-filamentous material). In both diseases it is a matter of alterations of the little vessels, in endothel and basement membranes. We find here the same fine granular-filamentous substance in the elastic fibers of lamina interna, where as in P.e. we can see the calcification.

[Electron microscopic investigation of the leishmaniasis cutanea. I. Leishmania tropica in the tissue (author's transl)]. / Elektronenmikroskopische Untersuchungen der Leishmaniasis cutanea. I Leishmania tropica im Gewebe

On two patients suffering from Leishmaniasis cutanea from the old world florid and later a residual lesion could be removed for electron-mircroscopic examination, and the following was found: 1. A pseudocarcinomatous follicular epidermal proliferation in the florid lesion. 2. Macrophages with one to three Leishmania cells can be proved in histiocytes nests. The parasites are not always clearly surrounded by host cell membrane. 3. The endocellular Leishmania cells have a ciliary system which is open on the outside. It is, therefore, correct to speak of a cryptomastigotic shape of the flagellum. The kinetoplast shows direct transition to mitochondria. The number of periplast fibrillae or tubuli amounted to 95-97 which is less than in other types of Leishmania. Yet no further morphological distinctive feature between Leishmania tropica and the other types is discernible when a comparison with the pertinent literature is made. 4. No parasites to be considered virulent were found now in the late residual focus of previously secured cutaneous Leishmaniasis. The macrophages, on the other hand, contained big vacuoles with lamellar residual substances. These are regarded as rests of the parasites.

[Electron microscopical investigation of rhinoscleroma (author's transl)]. / Elektronenmikroskopische Untersuchungen des Rhinoscleroms

A boy from Togo with a resistent Rhinoscleroma was observed. The specific granuloma was examinated by histological and electron microscopic methods. The plasma cells form fibrillary material or guttate Russel bodies in the rough endoplasmatic reticulum. The morphology of Mikulicz-cells and Klebsiella rhinoscleromatis is described. The cells are supposed to be (histiocytic) macrophages. The surface of the germs is coated with a fimbria-like radiate substance which in the vacuoles of the cells is crosslinked. This material could be the eliciting antigen for the formation of Russel bodies. These bodies then may represent immune substances bound within the cell.