" A cell characteristic of a clear cell adenocarcinoma; a round expansion of clear cytoplasm projects into the lumen of neoplastic tubules, but the basal part of the cell containing the nucleus is narrow."
■ A cell that juts above an adjacent epithelial or endothelial surface or lining.
■ Hobnail pattern’s significance differs according to the organ.
■ It can be neoplastic , examples:
A) Mesonephroid-type ovarian cystadenocarcinoma.
B) Clear cell carcinoma
C) Endometrial carcinoma
D) Collecting duct carcinoma
■ It can be reactive, examples:
A) Jutting of type II pneumocytes above the alveolar lining in lungs with diffuse alveolar damage or
B) Bulging of succulent, secretion-filled, vacuolated, enlarged and pleomorphic apocrine cells in the lobules of a lactating breast.