Soft tissue
Fibroblastic / myofibroblastic
Fibromatosis
Lipofibromatosis
Authors: Ali Chaudri, M.D., Jerad M. Gardner, M.D.
Last author update: 1 June 2013
Last staff update: 26 April 2023
Copyright: 2002-2024, PathologyOutlines.com, Inc.
PubMed Search: Lipofibromatosis [title]
Table of Contents
Definition / general | Epidemiology | Clinical features | Case reports | Gross description | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Negative stains | Molecular / cytogenetics description | Differential diagnosisCite this page: Chaudhri A. Lipofibromatosis. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/softtissuelipofibromatosis.html. Accessed December 26th, 2024.
Definition / general
- Pediatric tumor with predilection for hands and feet, composed predominantly of mature adipose tissue with proliferative fibroblasts in adipose septa (Stanford University)
- Previously called infantile fibromatosis of non-desmoid type
- First described in 2000 using "lipofibromatosis" (Am J Surg Pathol 2000;24:1491)
Epidemiology
- Rare childhood tumor (first surgery usually at age 1), 2/3 male, often of distal extremities
Clinical features
- Associated with macrodactyly of foot (Foot Ankle 1991;12:40)
- Clinically resembles lymphatic malformation or lymphedema
- Recurs locally due to lack of securing clean margins at resection, no metastases
Case reports
- Infant boy with lipofibromatosis in foot (Skeletal Radiol 2008;37:555)
- Lipofibromatosis arising in a pediatric forearm (Ups J Med Sci 2005;110:259)
Gross description
- White-tan or yellow with obvious fatty component, 1 - 3 cm
Microscopic (histologic) description
- Lobules of mature adipose tissue with fibroblastic foci consisting of bland fibroblasts involving adipose septa with a preserved lobular architecture
- Often have minute small univacuolated cells at interface between fibroblasts and adipose
- No atypia, no/rare mitotic figures
- Rarely pigmented cells are associated with fibroblastic element; resemble those in Bednar tumor, pigmented neurofibroma, nevi
Microscopic (histologic) images
Contributed by Mark R. Wick, M.D.
Positive stains
- Spindle cells: CD34, CD99, smooth muscle actin
- Variable BCL2, S100, EMA, muscle specific actin
Negative stains
Molecular / cytogenetics description
- Rare t(4;9;6) translocation in 5 year old boy (Cancer Genet Cytogenet 2007;179:136)
Differential diagnosis
- Fibromatosis: solid sheet-like fibrous growth, minimal to no fat
- Fibrous hamartoma of infancy: has primitive oval cell component with myxoid stroma
