[Cytomorphologic and cytophotometric studies in malignant midline reticulosis]

Biopsies of two patients with a clinical diagnosis of lethal midline granuloma were examined by electron microscopy, histology and cytology. Morphological changes included necrosis, inflammation, and infiltration of atypical histiocytic cells. Judging by the cellular characteristics, the DNA-content and -distribution pattern, this localised, invasive and destructive lesion is a low-grade malignant histiocytic tumour. Our results show that final tumour diagnosis can only be established by special cytological methods.