Sequestration of lichen compounds by lichen-feeding members of the Arctiidae (Lepidoptera).

A survey for the presence of sequestered lichen compounds in 103 wild-caught imagines representing eight different genera and 16 different species of the Arctiidae was conducted. Known lichen compounds were detected for the first time in 24 of the analyzed specimens (representing five different genera and 11 different species) based on their HPLC retention times and on their UV-absorption spectra. The anthraquinone parietin, the depside atranorin, as well as a hydrolytic cleavage product of the latter were among the lichen compounds most frequently detected in wild-caught imagines. The observed variation of sequestered lichen compounds in wild-caught imagines with unknown feeding history may be due to several reasons. Lack of lichen compounds in imagines may have been caused, for example, by larvae feeding on lichens with no or only minute amounts of phenolic products. The age of the specimens analyzed may also influence the results obtained. Avoidance of lichen compounds by selective feeding on those parts of lichen thalli that have no or little lichen products may be another reason for the lack of lichen compounds in imagines. Preliminary feeding experiments conducted with larvae ofEilema complana, for example, indicated that the larvae fed exclusively on the algal layer and cortex of the lichenCladonia pyxidata, whereas the medulla, which is rich in fumarprotocetrarie acid, was avoided. As expected, imagines hatching from the larvae were free of this lichen compound. Any ecological role of the sequestered lichen compounds for the herbivores is unknown. It is possible, however, that sequestered lichen compounds may be utilized for the chemical defense of arctiid moths or against microbial pathogens.

[Pigmented Paget's disease and pigmented breast cancer metastasis. Clinical and histologic simulation of malignant melanoma of the breast]. / Pigmentierter Morbus Paget und pigmentierte Mammakarzinommetastase. Klinische und histologische Nachahmer maligner Melanome der Brust.

Pigmented epidermotropic breast carcinoma has to be included in the differential diagnosis of pigmented lesions of the breast. Two rare cases of pigmented Paget's disease and pigmented metastatic breast carcinoma are presented, which mimicked malignant melanoma in both clinical and histological criteria.

[Lymphoepithelioma-like carcinoma of the skin]. / Lymphoepitheliom-ähnliches Karzinom der Haut.

Lymphoepithelioma-like carcinoma of the skin (LECS) is a rare cutaneous tumour with histological features resembling those of Epstein-Barr virus-induced nasopharyngeal carcinoma. An LECS tumour may mimic lymphoid follicles in its composition. Its distinct histological pattern, however, is based on syncytial nests and cords of large pale-staining epithelial tumour cells surrounded by a dense lymphoplasmacytic infiltrate. Tumour cells show conspicuous vesicular nuclei with delicate chromatin and few prominent nucleoli. Histological differential diagnosis must include malignant lymphomas, Merkel cell tumour, squamous cell carcinoma and cutaneous metastasis of lymphoepithelioma. Immunostaining with anticytokeratin antibodies is highly significant in the differential diagnosis. Histological and immunohistological findings in an LECS removed from the upper lip of a 56-year-old women are reported. Serologic investigations did not indicate EBV-associated tumour growth.

[Systemic proliferative angioendotheliomatosis: a cutaneous manifestation of malignant B-cell lymphomas. Histologic and immunohistologic studies of two cases]. / Angioendotheliomatosis proliferans systemisata: eine kutane Manifestation maligner B-Zellen-Lymphome. Histologische und immunhistologische Untersuchungen an zwei Fällen.

Angioendotheliomatosis proliferans systemisata (AEPS) is a rare disease entity characterized by a predominantly intravascular proliferation of tumour cells. Two forms of AEPS are differentiated: a very rare, benign and self-limiting form, which is endothelial in origin, and a more common, malignant form, which is an angiotropic intravascular malignant B-cell lymphoma. Histological and immunohistological investigations of the malignant form of AEPS are presented: In a 69-year-old woman cutaneous lesions appeared 5 months before the diagnosis of B-immunoblastic lymphoma. In a 57-year-old woman lesions were observed simultaneously with the relapse of a high-grade malignant B-cell lymphoma. Immunohistological identification of the proliferating cell type made diagnosis of intravascular B-cell lymphoma possible in paraffin-embedded biopsies.

[Solitary encapsulated neuroma]. / Das solitäre, umkapselte Neurom.

Solitary encapsulated neuroma (EN) is a true neuroma that is seldom diagnosed clinically. EN is the most frequently excised benign neuroma of the skin and has to be included in the differential diagnosis of small nodular facial tumours of middle-aged people. We report histological studies of 79 EN. EN are distinctive true neuromas that can easily be distinguished from all other benign neural neoplasms except the neuromas in the multiple mucosal neuroma syndrome.