Soft tissue
Fibroblastic / myofibroblastic
Calcifying aponeurotic fibroma
Author: Komal Arora, M.D.
Topic Completed: 1 July 2012
Minor changes: 21 March 2019
Copyright: 2002-2018, PathologyOutlines.com, Inc.
PubMed Search: Calcifying aponeurotic fibroma
Table of Contents
Definition / general | Clinical features | Case reports | Treatment | Clinical images | Gross description | Microscopic (histologic) description | Microscopic (histologic) images | Cytology description | Positive stains | Negative stains | Electron microscopy description | Molecular / cytogenetics description | Differential diagnosis | Additional referencesCite this page: Arora K. Calcifying aponeurotic fibroma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/softtissuecalcifying.html. Accessed August 11th, 2020.
Definition / general
- Rare, slow growing, painless tumor with fibroblasts palisading around chondroid or calcified nodules, usually in hands and feet of children or young adults; rarely at other sites (Hum Pathol 1998;29:1504)
- Also called juvenile aponeurotic fibroma
Clinical features
- 50% recur, especially in children
- Does not metastasize
- May be cartilaginous analog of fibromatosis
Case reports
- 2 year old child with giant intramuscular calcifying aponeurotic fibroma of gluteus maximus (Ann Trop Paediatr 2010;30:259)
- 10 year old girl with elbow tumor (J Med Invest 2011;58:159)
- 16 year old girl with foot tumor (Case of the Week #47)
- 36 year old woman with distal phalangeal bone involvement (Korean J Radiol 2008;9:91)
- Recurrent tumor of the thumb (J Hand Surg Am 2011;36:110)
Treatment
- Conservative excision with reexcision as necessary for recurrences
Clinical images
Images hosted on other servers:
46 year old woman
36 year old woman with distal phalangeal bone involvement
Gross description
- Nodular or infiltrative gray-white, gritty mass in subcutaneous tissue or tendon, may be calcified, usually 3 cm or less in hands or feet, may be larger elsewhere
Microscopic (histologic) description
- Nodules of plump or epithelioid fibroblasts palisading around cartilage and spotty calcification
- Cells have indistinct and variable cytoplasm, plump oval nuclei with vesicular chromatin that may be condensed below nuclear membrane
- Fibrocytes in stroma between nodules have dense, evenly dispersed chromatin
- May infiltrate fat or striated muscle at periphery
- Frequent osteoclast-like giant cells
- Rare mitotic figures, no atypia
- More cellular in very young
Microscopic (histologic) images
Images hosted on PathOut servers:
Poorly circumscribed
fibroproliferative
process with scattered,
linear and calcified zones
Amorphous calcification
surrounded by palisading
cells suggestive of rheumatoid
nodule or crystals
Typical zonation pattern
has cellular, plump fibroblastic
cells palisading around a hyalinized
collagenous zone, which in turn
surrounds the calcification
Palm, courtesy of Mark R. Wick, M.D.
Cells adjacent to hyalinized layer are commonly more rounded
Chondroid area is adjacent to calcification
16 year old girl with foot tumor
Images hosted on other servers:
H&E
Cytology description
- Benign appearing spindle cells, chondroid cells, multinucleated giant cells and calcified debris (Diagn Cytopathol 2001;24:336)
Positive stains
- Vimentin, CD68, CD99, S100, muscle specific actin (50%), smooth muscle actin (50%)
Electron microscopy description
- Chondrocytes, fibroblasts and occasional myofibroblasts
Molecular / cytogenetics description
- Benign, but may be aneuploid (Cancer 1994;73:1200)
Differential diagnosis
- Chondroma of soft parts: may involve hands, but usually well circumscribed with more well developed chondroid differentiation, no infiltration of adjacent tissue, no surrounding epithelioid cells
- Fibrous hamartoma of infancy: immature mesenchyme, fibroblasts are arranged in trabeculae but no palisading, no cartilage or calcification, not hands and feet
- Infantile fibromatosis: usually involves head, neck and proximal extremities in infants, not hands and feet of children/young adults, background is more myxoid than chondroid, calcification is rare
- Superficial [palmar and plantar] and desmoid fibromatosis: usually no calcification or chondroid differentiation
Additional references
