Inflammatory pseudotumor of the colon

Abstract

Inflammatory pseudotumor refers to a nonmalignant or low-grade neoplastic lesion characterized by the presence of spindle-cell proliferation with abundant inflammatory cells. Lung and orbit are the most frequent sites of occurrence, but the lesions may originate in nearly every site in the body, including the abdomen. We present a rare and interesting case of inflammatory pseudotumor of the colon in a 21-year-old male who presented to the emergency room with abdominal pain.

Keywords: CT, computed tomography.

Figure 1

21-year-old man with inflammatory pseudotumor of the colon. Ultrasound of the abdomen with color doppler at the level of right upper quadrant demonstrates heterogeneous, complex, multiseptated, predominantly cystic mass with solid hyperechoic component revealing increased vascularity (arrow).

Figure 2

21-year-old man with inflammatory pseudotumor of the colon. Contrast-enhanced CT axial (A) and coronal (B) reformatted images of the upper abdomen demonstrate complex, multiseptated, predominantly cystic mass in the right upper and mid abdomen (white arrows). The mass closely abuts the right colon (black arrows).

Figure 3

21-year-old man with inflammatory pseudotumor of the colon. Surgically resected specimen reveals a 9.5-cm, multiloculated, cystic mass adherent to the wall of right colon. Internal contents varied from tan serous fluid to pasty dark-brown material. Note relationship with the adjacent colon (C).

Figure 4

21-year-old man with inflammatory pseudotumor of the colon. Haematoxylin-eosin stain with magnification of 40 × demonstrates myofibroblastic spindle-cell proliferation mixed with inflammatory cell infiltrate.