August 2018
- 40 year old male presented with a 2.4 cm mass on the forearm.
- Cyst
- Lipoma
Sections show a well-circumscribed neoplasm based within the subcutaneous tissue.
Higher magnification shows the neoplasm is composed of numerous osteoclast-like giant cells and similar-appearing mononuclear cells.
Giant cell tumor of tendon sheath
- Giant cell tumor of tendon sheath is a benign soft tissue neoplasm that typically arises during the third to fifth decades of life
- These tumors present as painless, firm, slow growing masses that often occur on the volar aspects of the hands and feet, most commonly near the distal interphalangeal joint
- Histopathology reveals a well-circumscribed nodule based within the deep dermis or subcutaneous tissue composed of numerous osteoclast-like giant cells and mononuclear cells with similar-appearing nuclei
- Histiocytes containing hemosiderin and lipid are also commonly present
- The tumor cells are positive for CD68 by immunohistochemistry
- Surgical excision is curative but approximately 25% of cases may locally recur
- Giant cell tumor of tendon sheath is a benign soft tissue neoplasm
- These tumors present as painless, firm, slow growing masses that often occur on the volar aspects of the hands and feet
- Histopathology reveals a well-circumscribed nodule based within the deep dermis or subcutaneous tissue composed of numerous osteoclast-like giant cells and mononuclear cells with similar-appearing nuclei
- Surgical excision is curative but approximately 25% of cases may locally recur