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 January 16th, 2021.
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
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
AFIP images
Contributed by Mark R. Wick, M.D.
Case #47
Images hosted on other servers:
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