Nonneoplastic signet-ring cell change in gastrointestinal and biliary tracts: a pitfall for overdiagnosis.

Nonneoplastic signet-ring cell change (SRCC) is a rare but known phenomenon in gastrointestinal and biliary tracts and is always associated with underlying mucosal ulceration/erosion secondary to infection, ischemia, or other etiology. Because nonneoplastic SRCC closely mimics signet-ring cell adenocarcinoma (SRCA), differentiation of these 2 entities is critical because misdiagnosis of nonneoplastic SRCC as SRCA can lead to intense therapeutic interventions such as surgery and/or chemoradiation therapy. In this review, a brief overview on nonneoplastic SRCC in gastrointestinal and biliary tracts, including the spectrum of clinical presentation, important histologic features, and immunohistochemical markers that are useful in differentiating nonneoplastic SRCC from SRCA, is provided. The pathogenesis of nonneoplastic SRCC in gastrointestinal and biliary tracts is discussed.