Table of Contents
Definition / general | Epidemiology | Case reports | Treatment | Clinical images | Gross description | Microscopic (histologic) description | Microscopic (histologic) images | Electron microscopy description | Electron microscopy images | Positive stains | Molecular / cytogenetics description | Differential diagnosis | Additional referencesCite this page: Arora K. Fibroma of tendon sheath. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/softtissuefibromatendon.html. Accessed January 22nd, 2021.
Definition / general
- Well circumscribed, lobulated fibrous tumor attached to tendon or tendon sheath
- Also called tenosynovial fibroma
- Benign, uncommon
- May overlap with nodular fasciitis (Am J Surg Pathol 1989;13:472) or giant cell tumor of tendon sheath (Mod Pathol 1995;8:155, Histopathology 1992;20:213)
Epidemiology
- 60% men, ages 30 - 50 years old with nodule on fingers, hands or wrist
Case reports
- 35 year old man with swelling and mild discomfort on the volar and ulnar aspect of the left hand (Internet Journal of Hand Surgery 2008;2(1))
- 61 year old man with a history of multiple cutaneous nodules on both palms and soles (Ann Dermatol 2011;23:S45)
- Medial canthus of eye (Ophthal Plast Reconstr Surg 2007;23:341)
Treatment
- Excise to relieve symptoms but preserve function, may be difficult to remove from adherent tendons
- Benign, but up to 24% recur; does not metastasize
Gross description
- Well circumscribed, small fibrous multinodular mass < 3 cm, cut surface is pale, solid and homogeneous
Microscopic (histologic) description
- Well circumscribed nodules of dense fibrous tissue with occasional spindle or stellate mesenchymal cells in S or C shaped patterns
- Cells have scant cytoplasm and elongate nuclei with evenly distributed fine chromatin
- Often dilated or slit-like channels / clefts resembling tenosynovial spaces
- Varies from cellular to paucicellular
- May have bizarre tumor cells, extravasated red blood cells, but no atypical mitotic figures, no necrosis, no hyperchromasia
Microscopic (histologic) images
AFIP images
Electron microscopy description
- Resembles myofibroblasts and fibroblasts
Positive stains
Molecular / cytogenetics description
- May have t(2;11)(q31-32;q12) (Histopathology 1998;32:433)
Differential diagnosis
- Sarcoma: rare in hands and feet, usually large masses with cellularity, marked chromatin abnormalities and abnormal mitotic figures
- Benign fibrous histiocytoma: usually not hands or feet, prominent histiocyte-like cells, foam cells, giant cells and hemosiderin, CD68+
- Giant cell tumor of tendon sheat: more cellular, cells have histiocyte-like nuclei, also prominent giant cells, foam cells, hemosiderin; no slit-like vascular spaces, no extensive hyalinized stroma
Additional references