Reactive Nodular Fibrous Pseudotumor of Mesentery
Elizabeth A. Montgomery, MD
Key Facts
Terminology
Lesion of mesentery composed of stellate and spindle-shaped cells arranged in collagen-rich stroma with lymphoid aggregates
Clinical Issues
Frequent history of prior operations, evidence of prior bowel perforation, or history of pancreatitis
Some patients have multiple nodules
Excellent prognosis; benign process
Microscopic Pathology
Multilobulated appearance
Predominantly involving subserosa and extending into submucosa
Frequent lymphoid aggregates
Sparse intralesional mononuclear cells
Hypocellular spindle cell lesion
Bland cytologic features
 Hematoxylin & eosin shows low magnification of a reactive nodular fibrous pseudotumor involving the mesentery extending up into the deep gastric submucosa. |
 Hematoxylin & eosin shows a higher magnification of the lesion. There are a few plasma cells along with fibroblastic cells and a collagenized background. |
TERMINOLOGY
Definitions
Lesion of mesentery composed of stellate and spindle-shaped cells arranged in collagen-rich stroma with lymphoid aggregates
CLINICAL ISSUES
Epidemiology
Incidence
Rare
Age
Predominantly adults
Gender
No predominance
Presentation
Obstruction
Frequent history of prior operations, evidence of prior bowel perforation, or history of pancreatitis
Some patients have multiple nodules
Some lesions associated with foreign bodies
Most in small bowel (ileal) mesentery
Also in colon mesentery and in bed of area of prior pancreatitis
Treatment
Surgical excision
Prognosis
Excellent; benign process
MACROSCOPIC FEATURES
Size
1.5 cm to > 10 cm
