A signet ring cell shows:
(1) The cytoplasm is filled with a large spherical vacuole or inclusion.
(2) The nucleus is compressed into a crescent shape.
(3) The nucleus is at the periphery of the cell.
Benign conditions that may have epithelial signet ring cells:
(1)
pseudomembranous colitis
(2) ulcerated tubular adenoma
(3) Peutz-Jeghers polyp
(4) ischemia
(5) acute erosive gastropathy
(6) mucosa-associated lymphoid tissue (MALT)
(7) cystic fibrosis
(8) ulcerative colitis
Benign conditions that may have nonepithelial signet ring cells:
(1) muciphages
(2) Schwannoma
(3) adipocytes
Malignant conditions that may have signet ring cells:
(1) signet ring adenocarcinoma (stomach, colon, etc)
(2) malignant lymphoma
(3) ovarian adenocarcinoma
(4) malignant melanoma
Nonneoplastic epithelial signet ring cells are:
(1) keratin positive
(2) E-cadherin positive
(3) p53 and Ki-67 negative
