Recurrent symptoms in well-established celiac disease may result in further clinical evaluation. In most, poor diet compliance is present. Other considerations include an unidentified gluten source, an erroneous initial diagnosis, another or second and superimposed cause for symptoms, or a complication, including collagenous sprue or an intestinal lymphoma. Failure to define an initial gluten-free diet response, however, suggests that celiac disease may not be present. Instead, a distinctive enteropathic process, refractory to diet restrictions, including gluten, is evident. This "sprue-like" intestinal disorder or enteropathy remains unclassified, and probably, represents a heterogeneous entity. Molecular changes suggestive of early clonal expansion of an aberrant population of intraepithelial lymphocytes may be detected in some (with or without a prior gluten-free diet response), and these changes may signify an early or "cryptic" lymphoma. Other newly recognized lymphoproliferative disorders occurring in the setting of celiac disease have been recorded, including hepatosplenic delta-gamma T-cell lymphoma, an indolent CD4+ T-cell lymphoma, particularly in younger males, and large granular lymphocytic leukemia, a possibly treatable disorder characterized by the clonal expansion of T-cells in blood and small intestinal mucosa. Studies using IL-15 blockade in a transgenic mouse model with pathologic features of a sprue-like intestinal disease has led to human clinical trials with encouraging positive results.