Background Follicular dendritic cell sarcoma (FDCS) is a rare neoplasm of mesenchymal origin. FDCS of gastrointestinal tract (GI) are exceedingly uncommon. Case presentation We report the first case of classic type FDCS in a 34-year-old male with Birt-Hogg-Dubé syndrome, which presented as a mass at the ileo-cecal junction. He received no further treatment after resection and remained disease free for 3.5 years. We further analyze and review the clinical and pathologic findings of 33 cases of GI tract FDCS reported in the literature. Conclusions There are two distinct subtypes of FDCS in the GI tract: the classic type occurs in relatively younger patients (mean = 45.3 years) without Epstein-Barr virus (EBV) association, and behaves more aggressively; the inflammatory subtype presents as colonic polypoid tumor in older patients (mean = 60.7 years) and is EBV positive. The clinical outcome in the latter group appears favorable although mortality rate is not necessarily low.

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Hepatoid adenocarcinoma (HAC) is an uncommon and aggressive type of adenocarcinoma, typically affecting the middle-aged and elderly. The morphological features of the HAC resemble hepatocellular carcinoma. Presenting symptoms may include upper abdominal pain, hematemesis, back pain, and palpable abdominal mass. HAC has no proven therapy, and the prognosis is extremely poor. Early surgical removal with chemotherapy remains the standard of care. We describe one of the youngest patients in the literature with HAC who presented with acute pancreatitis. The diagnostic workup was confused by diffuse lymphadenopathy and elevated β-human chorionic gonadotropin making lymphoma and germ cell tumor likely possibilities until immunohistochemistry confirmed the diagnosis.