Ileal Mucosa-Associated Lymphoid Tissue (MALT) Lymphoma with a Large-Cell Component That Regressed Spontaneously

Abstract

Reported herein is a case of mucosa-associated lymphoid tissue (MALT) lymphoma of the terminal ileum with a large-cell component, which regressed spontaneously. To the best of our knowledge, only five cases of spontaneously regressing MALT lymphoma have been reported in the English-language literature, and all of these cases were low-grade lymphomas. Spontaneous regression of a MALT lymphoma with a high-grade component is very rare. The present case suggests that MALT lymphoma cells have a reversible nature, even in the presence of a high-grade component.

Keywords: Ileum, Low grade; Large cell component; Mucosa-associated lymphoid tissue lymphoma; Regression.

Fig. 1

Radiological and endoscopic findings of an ileal lesion in one patient. (A) February 3, 2007: computed tomography (CT) finding of slightly enlarged ileocecal lymph nodes (arrow). (B) February 16, 2007: colonoscopic examination disclosed multiple protruding lesions with erosive tops and covered by edematous mucosa in the terminal ileum. (C) March 23, 2007: CT findings of no detectable ileocecal lymph nodes. (D) April 5, 2007: no lesions could be found in the terminal ileum on colonoscopic examination.

Fig. 2

Pathological findings of ileal lesions. (A) Dense, homogenous, diffuse mononuclear cell infiltration was demonstrated in biopsy specimens of the terminal ileal mucosa (H&E stain, original magnification, ×100). (B) Lymphoepithelial lesions were clearly detected by immunohistochemistry against cytokeratin AE1/AE3 (DAKO; original magnification, ×400). (C) Diffuse large-B-cell lymphoma-like cells with swollen, light-colored nuclei and a high nuclear-cytoplasmic ratio in a biopsy specimen of the terminal ileum. (D) Immunohistochemistry against CD10 (original magnification, ×400). (E) Immunohistochemistry against BCL2 (original magnification, ×400).