Duodenal-Type Follicular Lymphoma Mimic Follicular Hyperplasia

Keywords

Primary follicular lymphoma of duodenum, Spontaneous regression

A 56-year-old Japanese woman with no notable medical history was admitted to our clinic because of abnormal changes in upper gastrointestinal series for regular checkup. An upper gastrointestinal endoscopy was performed. In the duodenum, white plaques resembling lymphoid hyperplasia were detected (Figure 1A, arrowheads). A biopsy was followed by the diagnosis of duodenal-type follicular lymphoma (FL) (Grade 1) (Figure 2). No other lesions were detected by further examinations (Stage I). Four courses of rituximab monotherapy (375 mg/m² every 4 weeks) were administered. No antibiotics were used. At 1 year after the diagnosis, an upper endoscopy revealed the same lesion with slight regression. Two years after the diagnosis, the lesion had diminished (Figure 1B). Four years post-diagnosis, the lesion had reappeared but a biopsy revealed only lymphoid hyperplasia with no malignancy (Figure 1C, arrowheads). The patient is being followed up without any additional treatment.

Duodenal-type FL is a rare distinct variant of follicular disease characterized by lymphomatous disease limited to the duodenum, defined in the 2016 WHO classification [1,2]. Usually, multiple 1-5 mm polypoid lesions in the descending part of the duodenum are observed [1,3,4]. It is often difficult to distinguish duodenal polypoid lesions from lymphoid hyperplasia by endoscopic appearance, particularly when they are smaller in size or fewer in number. The most important thing is whether the gastroenterologist considers the possibility of FL and performs a biopsy or not. A pathological diagnosis is necessary to confirm the diagnosis.

Duodenal-type FL is distinct from other gastrointestinal-tract FLs. Duodenal-type FL patients appear to have an excellent prognosis, and watchful waiting and single-agent rituximab treatment may be sufficient [1,3,4].

Conflicts of Interest

The authors state that they have no conflicts of interest to declare.

References

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