Intravascular Large B-Cell Lymphoma Diagnosed on Gastroesophageal Junction Biopsy During Evaluation of Dysphagia

Intravascular large B-cell lymphoma is a rare aggressive lymphoma confined to small-vessel lumina that may elude endoscopic detection. Diagnosis from a gastroesophageal junction biopsy is rarely reported. A 75-year-old woman underwent upper endoscopy for dysphagia, revealing only an irregular Z-line. Histopathology demonstrated CD20-positive atypical lymphoid cells within submucosal vessel lumina, suspicious for intravascular large B-cell lymphoma. She was referred for hematologic staging and rituximab-based chemotherapy. This case illustrates that an irregular Z-line, attributed to reflux, can be the only mucosal evidence of an occult systemic lymphoma; systematic biopsy of even subtle findings is decisive in this rapidly fatal but curable disease.