The spontaneous occurrence of apoptosis in squamous carcinomas of the uterine cervix

A distinctive type of individual ceil necrosis occurring in squamous carcinomas of the uterine cervix has been studied by light and electron microscopy. The first stage of the process involves condensation and fragmentation of scattered tumour cells with the production of compact, membrane-bounded bodies in which organelles appear well preserved. These are then phagocytosed by either neoplastic epithelial cells or histiocytes, and are degraded by lysosomal hydrolases. The phenomenon is identical with shrinkage necrosis or apoptosis, which has been described in non-neoplastic tissues under both physiological and pathological conditions, and in several other neoplasms. The findings indicate that cell loss by this means is often considerable in cervical carcinomas, and are consistent with the hypothesis that the spontaneous occurrence of apoptosis might largely account for the discrepancy known to exist between the rate of cell multiplication in malignant tumours and their rate of growth.