Giant cell tumor of tendon sheath
GCTTS has been classified into 2 types. The nodular type is often localized to the hands, has a pseudocapsule, and has a slight predilection for females. The diffuse type is often localized to larger joints and presents with multicentric tumors or satellite lesions without capsules. The diffuse type tends to recur after excision and affects both sexes equally.
GCTTS is thought to result from a reactive inflammatory process. Other hypotheses posit that it arises from the synovial membrane, sesamoid bones, or primitive mesenchymal cells.
Almost all cases are benign, but malignant degeneration has rarely been reported.
D48.1 – Neoplasm of uncertain behavior of connective and other soft tissue
95413004 – Nodular tenosynovitis
Differential Diagnosis & Pitfalls
- Myxoid cyst
- Hemangioma (see, eg, lobular capillary hemangioma)
- Glomus tumor
- Fibroma of the tendon sheath
- Ganglion cyst
- Foreign body granuloma
- Necrobiotic xanthogranuloma
- Tendinous xanthoma
- Rheumatoid nodule
- Epidermoid cyst
- Synovial carcinoma
- Knuckle pad
- Gouty tophus
- Granuloma annulare