Behcet's Disease Mimicking Crohn's Disease: A Diagnostic Pitfall in GI Tract Biopsies.

Behcet's disease is a rare entity. It's a multi-systemic inflammatory disease of unknown etiology characterized by recurrent ulcers and vasculitis, mainly including the oral cavity, eyes, gastrointestinal tract and joints. Crohn's disease is a chronic inflammatory disorder that may affect the same organs as Behcet's disease, however more frequently the gastrointestinal tract. Distinguishing Behcet's disease from Crohn's disease can be challenging due to the overlapping clinical presentation and similar morphology features on pathology biopsy specimens. This is a case report of a 32-year-old female who first presented at the emergency department with fatigue, weight loss, arthralgia, and erythema nodosum. The patient was admitted for oral ulcers, skin rash, genital ulcers, and melena one month later. Treatment with prednisone was started at the time and further workup for Behcet's disease versus inflammatory bowel disease was started. Her esophagus biopsy shows granulomatous-like vasculitis, and her colon biopsies show overlapping features with Crohn's disease. Herein, we present a rare and interesting case in which Behcet's disease mimics inflammatory bowel disease on the gastrointestinal tract biopsies but with some unique findings and diagnostic pitfalls for gastrointestinal tract vasculitis and ulceration.

Rectal endometriosis mimicking primary rectal adenocarcinoma.

Endometriosis is a benign entity defined as the presence of endometrium tissue outside of uterine cavity. It is a common disease involving peritoneum, pelvic organs, gastrointestinal tract, and so on. Diagnosis based on cytology specimen can be challenge when we encounter increased cytological atypia in the glandular epithelium, with abundant inflammatory cells and debris in the background. We presented a case of deep rectal endometriosis mimicking rectal adenocarcinoma on cytology specimen and on MRI imaging studies. The combination of endometrial glands, cellular Mullerian stroma, hemorrhage, and hemosiderin-laden macrophages are the characteristic features on cytologic specimens.