Squamous carcinoma in situ of the uterine cervix.I. classification and histogenesis

T invasive or in situ squamous cell carcinoma of the uterine cervix have been reported often1, iations in histologic structure have been recognized by many. Most observers have recognized a large cell or "differentiated" type and a small cell or "undifferentiated' type.l, 1 7 , 1 8 , 2 6 Despite the wide recognition of the "many faces" (Koss) of carcinoma in situ no significance has been attached to these variations nor has particular emphasis been placed on the fact that the variable patterns of in situ neoplasia form an almost continuous progression of changes. For easier communication and understanding we have attempted to simplify the diverse nomenclature which has been used for the variations of the in situ neoplastic process.