Localized tenosynovial giant cell tumor

Localized tenosynovial giant cell tumors is a subtype that is most commonly found in the fingers. On imaging, these lesions are commonly demonstrated as localized, solitary, subcutaneous soft tissue nodules, with low T1 and T2 signal and moderate enhancement. 

Please see the overview article tenosynovial giant cell tumor for content common to both the localized-type and diffuse-type.

Epidemiology 

Typically, they present in the 3^rd to 5^th decades and have a slight female predilection with an F:M ratio of 1.5-2.1:1 ^4,13. They are the second most common soft tissue mass of the hand and wrist.

Clinical presentation 

Clinically, localized tenosynovial giant cell tumors present as a slow-growing, painless mass ¹³.

Pathology

Localized tenosynovial giant cell tumors are most common in the fingers (~85%) where they are close to a tendon sheath or interphalangeal joint. Less commonly they can be found in the the wrist, ankle, foot, knee, and are rarely found in the elbow and hip ¹³. Localized tenosynovial giant cell tumors can be extra-articular (more common) or intra-articular ¹³.

Macroscopic appearance

Localized tenosynovial giant cell tumors are usually lobulated, well-cirumscribed masses between 0.5-4 cm and are white-to-grey with yellowish and brown regions ¹³.

Microscopic appearance

See main tenosynovial giant cell tumor article.

Radiographic features

Plain radiograph

Tenosynovial giant cell tumors appear as soft tissue density peri-articular masses and can cause pressure erosion of adjacent bone, or rarely can invade the bone mimicking an intraosseous lesion ^8,13. Periosteal reaction and calcification are uncommon ^4,5.

Ultrasound

Ultrasound is useful as it allows not only the characterization of the lesion but also is able to demonstrate the relationship with the adjacent tendon. On the dynamic scan, there is free movement of the tendon within the lesion. Typically they appear as:

• associated with the volar surface of the digits

• does not move with flexion or extension of adjacent tendons

• usually homogeneously hypoechoic, although some heterogeneity may be seen in echotexture in a minority of cases ¹

• most will have some internal vascularity

MRI

Localized type are a single mass with a capsule and small low intensity foci representing faint hemosiderin deposition ¹⁴. Bone erosion and neurovascular encasement can be seen ¹⁴.

Signal characteristics

• T1: low signal

• T2: low signal

• T1 C+ (Gd): often show moderate enhancement ⁶

• GE: low and may demonstrate blooming artifact

Treatment and prognosis

Tenosynovial giant cell tumors are usually benign and local surgical excision usually suffices, with local recurrence (seen in 4-30% of cases) requiring more extensive surgery with or without radiotherapy being uncommon ^1,13. Locally aggressive and malignant tenosynovial giant cell tumors can occur ¹¹. Metastases can occur, most commonly to lymph nodes and lung ⁴.

Differential diagnosis

See main tenosynovial giant cell tumor article.