Tumefactive Crohn's Disease Mimicking Colon Carcinoma in a Young Female: A Case Report.

Tumefactive Crohn's disease is a rare form of Crohn's disease that may mimic colon carcinoma macroscopically. This case report describes a 28-year-old female who presented with right-sided abdominal pain and a palpable abdominal mass that had persisted for over a month. Multiple hospitalizations failed to provide an accurate diagnosis until an exploratory laparotomy revealed that the "mass" was the cecum and a perforated ascending colon. A partial right colectomy was performed, sending the specimen for biopsy. The microscopic description showed dense and confluent chronic inflammation in the colonic mucosa and wall, extending to the serosa in some regions. The infiltration comprised lymphocytes and plasma cells, with an admixture of some neutrophils. Aphthous mucosal ulcerations, intramural fissures, and fistulas were present. Immunostains for pan-keratin demonstrated no intramural epithelial elements. The characteristics of this lesion represent tumefactive Crohn's disease. This case highlights the key microscopic characteristics that pathologists look for when differentiating Crohn's disease from colon carcinoma in a patient presenting with abdominal pain and a colon mass.