Gyriform duodenal mucosa as a manifestation of light chain deposition disease

An 80-year-old woman with para-aortic lymphadenopathy underwent upper gastrointestinal endoscopy as part of a malignancy screening procedure. She had no gastrointestinal symptoms. Endoscopy revealed a distinctive brain gyri-like mucosa extending from the duodenal bulb to the horizontal portion, characterized by enlarged villous structures and yellowish discoloration (Fig. 1). Duodenal biopsy demonstrated expansion of the villous lamina propria with pale eosinophilic amorphous deposits (Figs. 2, 3A), that were negative for direct fast scarlet (Fig. 3B) and Congo red staining, excluding amyloidosis. Light chain immunostaining revealed that the deposits were lambda-positive (Fig. 3C) and kappa-negative (Fig. 3D); therefore, the lesion was diagnosed as light chain deposition disease (LCDD). Concurrent lymph node and bone marrow biopsies confirmed lymphoplasmacytic lymphoma, and the lambda-positive light chain was attributed to the lymphoma cells. The lymphatic vessels were either collapsed or dilated and filled with light chains (Fig. 3E). Furthermore, lipid accumulation was observed in the surface absorptive epithelium and macrophages within the lamina propria (Fig. 3F). These findings suggest that extensive light chain deposition leads to lamina propria expansion and impaired lymphatic drainage, lipid accumulation, resulting in the gyriform appearance.

Fig. 1.

Endoscopic images showing yellowish mucosa extending from the duodenal bulb to the horizontal portion (A), and a closer view highlighting enlarged villi and the characteristic gyriform appearance (B).

Fig. 2.

Duodenal biopsy demonstrating expansion of the villous lamina propria with pale eosinophilic amorphous deposits (hematoxylin and eosin staining, ×100).

Fig. 3.

Special stain and immunohistochemistry. Pale eosinophilic deposits in the lamina propria (A, hematoxylin and eosin staining) are negative for direct fast scarlet staining (B). Immunohistochemistry showing lambda-light chain-positive deposits (C) and kappa light chain-negative staining (D). D2-40 staining showing collapsed or dilated lymphatic vessels filled with deposits (E, arrows). Adipophilin staining highlighting lipid accumulation in the epithelium and macrophages in the lamina propria (F). (A–F) ×400.

LCDD is a rare condition characterized by amorphous eosinophilic deposits of monoclonal immunoglobulin light chains. In contrast to amyloidosis, the deposits are non-fibrillar and negative for direct fast scarlet and Congo red staining. Gastrointestinal involvement is uncommon, with previous reports describing nonspecific endoscopic findings, including erosion and edema.1,2 To our knowledge, this is the first report demonstrating a unique brain gyri-like appearance. Notably, immunoglobulin M deposition in dilated lymphatics, leading to lipid accumulation and diarrhea, has been reported in Waldenström macroglobulinemia.3 Although the composition and distribution of deposits differ, both conditions share pathogenic mechanisms involving lymphatic obstruction and lipid accumulation. A written informed consent was obtained from the patient.