Fibroma of tendon sheath around large joints: clinical characteristics and literature review

Abstract

Background: Fibroma of tendon sheath (FTS) is a benign tumor arising from the synovium of the tendon sheath that occurs mostly around small joints such as the fingers, hands, and wrist. However, FTS rarely arises around a large joint (knee, shoulder, elbow, and ankle) with intra-articular or extra-articular involvement. The clinical characteristics of FTS arising around a large joint are unclear. An additional 3 cases of FTS arising around a large joint are presented. Furthermore, the published cases and the present cases are reviewed with respect to their clinical characteristics and imaging and histopathology findings.

Methods: The 43 reported cases including the present 3 patients were summarized, and the patients' profiles, symptoms, sites and locations in the joint involved by FTS, magnetic resonance imaging (MRI) findings, surgical procedures, clinical courses, and cytogenetic analyses were reviewed.

Results: The average age of 26 cases was 40.9 years (range 13-69 years), and about 60% of the patients were male. About 10% of the patients had a past history of trauma to the knee joint. Of the present 3 cases, one case was extra-articular around the elbow joint, one case was extra-articular around the knee joint, and one case was intra-articular involving the knee joint. The common symptoms were pain (62.5%), swelling or palpable mass (54.2%), and limited range of motion of the involved joint (50%). The most commonly involved joint was the knee, with 32 cases (74.4%), followed by the elbow in 5 cases (11.6%), ankle in 4 (9.3%), and shoulder in 2 (4.7%). The tumor typically exhibited iso to low signal intensity on T1-weighted MRI. T2-weighted images showed various patterns, but mostly low signal intensity relative to muscle. The surgical margin was marginal resection in all cases. There were no recurrences after surgery. On chromosomal analysis, only the present Case 3 showed an abnormality.

Conclusions: A total of 43 FTS cases that occurred around large joints were summarized. The most common site was around the knee joint. In FTS cases around large joints, it is necessary to distinguish between various fibroblastic and/or fibrohistiocytic tumors.

Keywords: Extra-articular; Fibroma of tendon sheath; Intra-articular; Large joint.

Fig. 1

T1- and T2-weighted MR images of Case 1. a On T1-weighted images, the mass (arrow) is isointense compared to muscle. b On T2-weighted images, the mass (arrow) has low signal intensity compared to muscle

Fig. 2

Histopathological findings of the resected tumor. The tumor is composed of spindle cells with low cellularity, and slit-like vessels (arrow) are present in the wavy collagenous stroma (hematoxylin and eosin stain)

Fig. 3

T1- and T2-weighted MR images of Case 2. a On T1-weighted images, the mass (arrow) is isointense compared to muscle. b On T2-weighted images, the mass (arrow) has high signal intensity in the center of the mass, and the surrounding area has low signal intensity

Fig. 4

Histopathological findings of the resected tumor. In the low power-field, there are areas where dense proliferation of collagenous tissue is seen (**), and sparsely growing areas (*) and slit-like clefts (arrow) are recognized (hematoxylin and eosin stain)

Fig. 5

MR images of Case 3. a On T1-weighted images, the lesion (arrow) is heterogeneously isointense and hypointense compared to muscle. b On T2-weighted images, the lesion (arrow) is heterogeneously hypointense. c On contrast-enhanced T1-weighted images, the lesion (arrow) shows mild and patchy contrast enhancement

Fig. 6

Histopathological findings of the resected tumor. The tumor consists of spindle cells resembling fibroblasts with a background of rich collagenous stroma (hematoxylin and eosin stain)

Fig. 7

Karyotyoe of intra articular FTS in Case 3. A representative karyotype of Case 3 showing a t(11;15)(q23;q22) translocation (arrows)