Hobnail adenocarcinoma of ovary. Coloured Scanning Electron Micrograph (SEM) of clear cell adeno- carcinoma cancer cells of the human ovary. Known also as Hobnail-type" adenocarcinoma for its irregular knobbly surface structure and the tumour cells (blue/pink) which have a clear cytoplasm. Between these cells are larger cells with many tiny microvilli projections (purple). Adeno- carcinoma is a malignant cancer, here arising on the epithelial surface of the ovary. Carcinoma is a common ovarian cancer which can spread and may be fatal. Treatment may involve surgery and chemo- therapy. Magnification: x10,400 at 6x7cm size. x13,300 at 4x5""