signet ring cell
Definition A usually malignant cell containing copious clear cytoplasm that flattens a hyperchromatic nucleus to one side, having an appearance likened to a signet ring.
Cancers composed predominantly of signet ring cells often carry a worse prognosis; the “classic”–and most common–signet ring cells occur in the stomach, but are well described in carcinoma of the breast, colon, gallbladder, lung, nasal cavity, prostate, thyroid—medullary
carcinoma and urinary bladder. Malignant signet ring cells may also be seen in non-epithelial malignancies–e.g., mesothelioma, rhabdomyosarcoma, balloon cell melanoma, oligodendroglioma, myxoid angioblastomatosis, myxoid liposarcoma, lymphoma, and is a morphology typical of normal fat cells, oligodendrogliocytes and muciphages.