Reference ID: SP-T-18A.
Diagnosis: Low-Grade Squamous Interepithelial Lesion (LSIL)

Discussion:
Cells occur singly and in sheets. Cytologic changes are usually confined to cells with "mature" or superficial-type cytoplasm. Overall size is large, with fairly abundant 'mature' well defined cytoplasm.
Nuclear enlargement more than three times the area of normal intermediate nuclei results in a slightly increased nuclear to cytoplasmic ratio. Variable degrees of nuclear hyperchromasia are accompanied by variations in nuclear size, number, and shape. Binucleation and multinucleation are common. Chromatin is often uniformly distributed, but coarsely granular; alternatively, the chromatin may appear smudged or densely opaque. Nucleoli are generally absent or inconspicuous if present. Contour of nuclear membranes is often slightly irregular, but may be smooth.
Cells have distinct cytoplasmic borders. Perinuclear cavitation ("koilocytosis"), consisting of a sharply delineated clear perinuclear zone and a peripheral rim of densely stained cytoplasm, is a characteristic feature but is not required for the interpretation of LSIL; alternatively, the cytoplasm may appear dense and orangeophilic (keratinized). Cells with cytoplasmic perinuclear cavitation or dense orangeophilia must aslo show nuclear abnormalities to be diagnostic of LSIL; perinuclear halos in the absence of nuclear abnormalities do not qualify for the interpretation of LSIL.

References:
Demay 2nd edition page - 68, 69, 168
Bethesda page - 91 to 98
Atkinson page - 42, 80.