Signet ring cell carcinoma of the gallbladder in a 22-year-old man: a case report and review of the literature.

Primary carcinoma of the gallbladder is an uncommon malignancy with a variable incidence among different geographic locales and ethnic groups. Women are affected generally 3 times as often as men. Choleliths are a significant risk factor. Other risk factors include abnormal union of the choledochopancreatic ducts, obesity, multiparity, chronic infection with certain bacteria, and genetics. The signet ring cell subtype of adenocarcinoma is a rare entity. The behavior of this subtype is not well described in the literature. The authors present a case of signet ring cell carcinoma of the gallbladder, unusual in their case because of the patient's young age, male gender, African American ethnicity, and lack of choleliths or any other risk factors. They review the literature in English to characterize this rare subtype.