[Granular cell tumor of the vermiform appendix. Case presentation with discussion of histogenesis]. / Granularzelltumor der Appendix vermiformis. Falldarstellung mit Diskussion der Histogenese.

Granular cell tumor is a rare lesion to the appendix. A case of that kind was recorded by the authors from a man, 32 years of age, who underwent surgery for appendicitis. Presence of a granular cell tumor was histologically, histochemically, and immunohistologically verified. Histogenesis of granular cell tumors is not well known, which prompted the authors to summarise some of their recent findings for discussion.

Experimental induction of embryo-derived teratomas and teratocarcinomas in mice.

The present study deals with the induction of teratomas and teratocarcinomas in two strains of mice (C3H/Bln and 129/terSv). 6 to 7 days old egg cylinders were transplanted beneath the kidney capsule of adult syngeneic male and female recipients. Out of 115 grafted embryos 32 gave rise to teratoid tumors. Both the overall tumor incidence (teratomas and teratocarcinomas) and the overall percentage of teratocarcinomas were approximately the same in the strains used. In strain C3H/Bln the gender of the recipient seemed to influence the outgrowth of malignant tumors. Two transplantable C3H-teratocarcinomas could be established (DTC-4, DTC-8). Up to date both have retained their pluripotent differentiation pattern which makes them useful for intended further investigations.

[Immunocytochemical studies of epithelial markers in pleural and peritoneal effusions as an adjunct to cytologic diagnosis]. / Immunzytologischer Epithelmarkernachweis in Pleura- und Aszitespunktaten als Ergänzung zur Zytodiagnostik.

Monoclonal antibodies were used in an indirect immunoperoxidase assay to investigate 83 smears of pleural or peritoneal effusions for expression of the epithelial markers MAM-6, MAM-3, and carcinoembryonic antigen (CEA). All but one smears containing tumor cells according to the evaluation of H&E preparations were positive for one, two or all three markers, the exception being a malignant melanoma. Three of 5 cases, suspicious by routine cytology, exhibited marker expression in a different number of cells and thus confirmed the cytological diagnosis. Five of 63 cytologically negative smears exhibited single cells or small cell clusters positive for up to three markers. Four of these patients were found to suffer from metastatic cancer, as established by clinical follow-up and subsequent biopsy or autopsy, respectively. Felty's syndrome and concomitant serositis were diagnosed and confirmed by autopsy in one of the MAM-6 positive cases with negative cytology. The comparatively strong MAM-6 expression in some mesothelial cells of this patient might have been induced by abnormal stimulation due to the rheumatic disease. The results of this study encourage wider use of immunocytochemistry as an adjunct to cytological diagnosis in effusions.