Metastatic lobular carcinoma with signet-ring cells mimicking primary gastric signet-ring cell carcinoma

Abstract

Signet-ring cell carcinoma (SRCC) is a subtype of adenocarcinoma characterized histologically by cells with abundant intracellular mucin production, creating a distinctive “signet-ring” appearance. SRCC typically arises in tissues of the gastrointestinal tract. In the breast, SRCC is a rare subtype of invasive lobular carcinoma defined by the presence of signet-ring cells. Mammary SRCC has unique patterns of metastatic spread compared to more common breast cancers, more often spreading viscerally to involve the serosal surfaces of stomach, urinary tract, and spleen. We report a case of metastatic mammary SRCC presenting in the stomach, thereby mimicking primary gastric SRCC. Recognition of this unusual presentation is critical as treatments for these malignancies are vastly different; misdiagnosis could lead to significant morbidity and mortality for patients.

Keywords

• Signet ring carcinoma
• Gastric metastases