Small bowel (small intestine)

Home Chapter Home Jobs Conferences Fellowships Books

Small bowel (small intestine)

Benign tumors and tumor-like conditions

Fibromatosis

Reviewer: Hanni Gulwani, M.D. (see Reviewers page)
Revised: 19 December 2012, last major update August 2012
Copyright: (c) 2003-2012, PathologyOutlines.com, Inc.

General
=========================================================================

● Uncommon in small bowel, rarely adheres to or penetrates bowel wall
● Usually in mesentery or retroperitoneum
● Also called intraabdominal desmoid tumor

Clinical features
=========================================================================

● Mean age 34 years old (younger than GIST patients)
● May be associated with trauma, familial polyposis coli, Gardner’s syndrome, hormonal stimulation
● Characterized by mutations in beta-catenin gene, CTNNB1 or APC gene (Oncologist 2011;16:682)
● Benign, but may recur

Case reports
=========================================================================

● 73 year old woman with tumor in jejunal pouch (World J Surg Oncol 2006;4:27)

Treatment
=========================================================================

● Surgical excision, radiation therapy, possibly chemotherapy

Gross description
=========================================================================

● Firm, tan, homogenous
● Usually large (6 to 25 cm) with infiltrative margins

Micro description
=========================================================================

● Broad, sweeping fascicles of bland spindle cells with minimal mitotic activity (mean 4 mitoses/50 HPF), bland nuclear features, finely collagenous stroma
● Infiltrative borders, evenly spaced blood vessels
● May involve muscularis propria but no necrosis, no hemorrhage, no myxoid degeneration, no epithelioid cells, no pleomorphism, no foam cells, no inflammatory cells

Micro images
=========================================================================

Other images

Positive stains
=========================================================================

● Vimentin, smooth muscle actin, desmin (50%)

Negative stains
=========================================================================

● CD34, S100, CD117 (some antibodies give CD117+ results)

Electron microscopy description
=========================================================================

● Myofibroblastic/fibroblastic differentiation

Differential diagnosis
=========================================================================

● GIST:: CD117+ with all antibodies, often CD34+, often malignant histologic features (Am J Surg Pathol 2000;24:947, Mod Pathol 2003;16:366)

End of Small bowel (small intestine) > Benign tumors and tumor-like conditions > Fibromatosis

This information is intended for physicians and related personnel, who understand that medical information is often imperfect, and must be interpreted in the context of a patient's clinical data using reasonable medical judgment. This website should not be used as a substitute for the advice of a licensed physician.

All information on this website is protected by copyright of PathologyOutlines.com, Inc. Information from third parties may also be protected by copyright. Please contact us at copyrightPathOut@gmail.com with any questions (click here for other contact information).