First report of a mucosa-associated lymphoid tissue (MALT) lymphoma of the esophagus diagnosed by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA).

Mucosa-associated lymphoid tissue (MALT) lymphoma of the esophagus is a rare tumor [1–3] with varying presentations [4]. Only a few reports have described MALT lymphoma of the esophagus spanning the entire circumference and length of the esophagus [3]. Many of these cases were diagnosed surgically. Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is an established method of obtaining submucosal tissue specimens [5]. We report here the first case of MALT lymphoma of the esophagus diagnosed by EUS-FNA. A 60-year-old woman attended our institution due to dysphagia. Upper gastrointestinal endoscopy revealed a smooth surface with visible capillaries over the entire circumference of the esophagus and a white, soft, elastic submucosal tumor covered by normal mucosa (●" Fig.1). An esophagogram showed a slightly elevated submucosal tumor extending over the entire esophageal length (●" Fig.2), and enhanced computed tomography demonstrated thickening of the left bronchial and esophageal walls along with swelling of the pharyngeal lymph nodes. Endoscopic ultrasonography revealed a tumorous lesion presenting as a primarily hypoechoic mass arising in the third layer, with a hyperechoic region. Because a diagnosiswas not reached using specimens obtained with biopsy forceps, EUS-FNA was performed (●" Fig.3). The presence of smallto medium-sized lymphocytic cells with mildly irregular nuclei, along with CD5(–), CD10(–), CD19(+), CD20(+), CD22 (+), and λ monoclonality on flow cytometry, led to a diagnosis of MALT lymphoma of the esophagus (●" Fig.4). We described the tumor as a Fig.1 Endoscopic findings in a 60-year-old woman with dysphagia: a large, rounded mass with normal overlying mucosa is seen extending longitudinally along the entire esophagus.