PATHOLOGY

Detailed explanation-1: -The term signet ring cell was originally used in the pathology literature to describe the morphology of adenocarcinomas where the nucleus has been peripherally displaced by an accumulation of cytoplasmic mucin, thus resembling the shape of a signet ring.

Detailed explanation-2: -The signet ring sign is seen in bronchiectasis when the dilated bronchus and accompanying pulmonary artery branch are seen in cross-section. The bronchus and artery should be the same size, whereas in bronchiectasis, the bronchus is markedly dilated.

Detailed explanation-3: -Signet ring lymphomas are proliferations of malignant lymphoid cells with cytoplasmic inclusions or vacuoles that displace the nucleus to the side of the cell, imparting a “signet ring” appearance. The cytoplasm may appear eosinophilic or clear and thus may mimic the appearance of adenocarcinoma cells.