S5995 Beyond the Expected: Primary Jejunal Lymphoma Masquerading as Occult Gastrointestinal Bleeding

Introduction: Primary jejunal lymphoma is a rare gastrointestinal malignancy that often presents with nonspecific symptoms, leading to diagnostic delays. Patients may experience progressive fatigue, weight loss, intermittent abdominal pain, nausea, and altered bowel habits, making early detection challenging. While gastrointestinal lymphomas are more frequently diagnosed in older men, this case highlights an atypical presentation in a young woman with persistent anemia and occult bleeding, emphasizing the need for heightened clinical suspicion in similar scenarios. Case Description/Methods: A 16-year-old woman with a history of progressive fatigue presented for evaluation. Laboratory studies revealed severe iron-deficiency anemia (Hb 7.1 g/dL) without overt gastrointestinal bleeding, raising suspicion for occult blood loss. Upper and lower endoscopy were unremarkable, leading to capsule endoscopy, which demonstrated ulcerated mucosa with active bleeding in the proximal jejunum. Due to the persistent anemia and inaccessible location of the lesion, the patient was taken to surgery, where an exploratory laparotomy was performed. Findings revealed an 80 cm segment of infiltrative disease with mesenteric extension and partial intestinal obstruction. Histopathological analysis confirmed diffuse large B-cell lymphoma (DLBCL), prompting initiation of R-CHOP chemotherapy. Discussion: This case highlights the atypical presentation of primary jejunal lymphoma, considering the patient’s young age, female sex, nonspecific symptoms, and jejunal involvement. Gastrointestinal lymphomas are uncommon, and even rarer in the proximal small intestine, making the diagnosis particularly challenging. The absence of overt gastrointestinal symptoms and the reliance on indirect signs, such as progressive fatigue and unexplained anemia, further complicated early detection. Recognizing these unusual clinical features is essential for timely diagnosis and intervention. In patients with persistent anemia and vague systemic symptoms, clinicians should maintain a high index of suspicion for rare gastrointestinal malignancies, even in atypical demographics. This case underscores the need to expand differential considerations beyond common etiologies, ensuring patients receive appropriate oncologic management without unnecessary delays.