Unusual manifestations of diffuse-type tenosynovial giant cell tumor in two patients: importance of radiologic-pathologic correlation

Pathology of intra-articular tumours and tumour-like lesions: pearls, pitfalls and rarities from a general surgical pathology practice

Intra-articular tumours are uncommonly encountered in routine practice and may present diagnostic challenges to pathologists. Challenges unique to this site include distinction from more common reactive synovial conditions, which are far more common; histologic variability; superimposed reactive changes; and often, lack of provided clinicoradiological context. This article reviews the pathology of the synovial tumours and tumour-like lesions, including diagnostic pearls, pitfalls and rare entities.

MRI Prediction Model for Tenosynovial Giant Cell Tumor with Risk of Diffuse-type

RATIONALE AND OBJECTIVES

To propose a magnetic resonance imaging (MRI) prediction model for diffuse-type tenosynovial giant cell tumors (D-TSGCTs).

MATERIALS AND METHODS

Anatomic locations were classified and then nodularity, margin, peripheral and internal hypointensity, and bone and cartilage involvement were evaluated on MRI. Student's t-test, chi-square test, diagnostic performance, logistic regression analysis, and decision tree were performed.

RESULTS

Nineteen intra-articular (11 localized; eight diffuse) and 55 extra-articular (44 localized; 11 diffuse) TSGCTs were included. Extra-articular D-TSGCTs showed significantly more frequent multinodular (72.7% vs. 25.0%, p = 0.009), and infiltrative lesions (90.9% vs. 34.1%, p = 0.002), without peripheral hypointensity (90.9% vs. 18.2%, p < 0.001), and contained granular internal hypointensity (72.7% vs. 31.8%; p = 0.003) with more frequent bone (81.8% vs. 27.3%; p = 0.003) and cartilage (50.0% vs. 0.0%; p = 0.038) involvement than localized-type. Intra-articular D-TSGCT also showed significance in all MRI features (100.0% vs. 9.1%, p = 0.001; 100.0% vs. 27.3%, p = 0.007; 100.0% vs. 36.4%, p = 0.018; 100.0% vs. 27.3%, p = 0.007; 50.0% vs. 0.0%, p = 0.038), except bone involvement (37.5% vs. 9.1%, p = 0.352) than localized-type. Cartilage involvement revealed the highest specificity (88.6-100.0%), regardless of location. Nodularity (100.0%; odds-ratio [OR]: 70.000) and peripheral hypointensity (90.9%; OR: 62.250) demonstrated the highest sensitivities ORs for D-TSGCT in intra-articular and extra-articular cases, respectively. MRI models for D-TSGCG beginning with the cartilage involvement in both anatomic locations and next on nodularity and peripheral hypointensity in intra-articular and extra-articular locations, respectively, exhibited sensitivity and specificity of 100% and 90.9% for intra-articular and 100% and 77.2% for extra-articular TSGCTs, respectively.

CONCLUSION

MRI can suggest the risk of D-TSGCT by combining imaging features with anatomic locations.

Tenosynovial giant cell tumors of digits: MRI differentiation between localized types and diffuse types with pathology correlation

OBJECTIVE

To compare the MRI findings between the localized- and diffuse-type tenosynovial giant cell tumors (TSGCTs) of digits with pathology correlation.

METHODS

Twenty-eight patients with newly diagnosed TSGCTs of digits (22 localized and 6 diffuse types) who underwent preoperative MRI and surgical excision were included from Jan. 2015 to September 2021. MRI findings regarding nodularity, margins, morphology of hypointensity with pathology correlation, and disease extent (bone erosion, articular involvement, muscle involvement, tendon destruction, and neurovascular encasement) were assessed.

RESULTS

Diffuse type was significantly larger (P = 0.006), more multinodular on both MRI and pathology (P = 0.038, both) with significant agreement, and infiltrative on both MRI and pathology (P < 0.001, both) with substantial agreement, and showed central granular on MRI and strong hemosiderin deposition on pathology (P = 0.022 and P = 0.021) with moderate agreement than localized type. Localized type showed significantly more frequent peripheral capsules on both MRI and pathology (P < 0.001, both) with moderate agreement than diffuse type. However, the septum on both MRI and pathology showed no statistically significant difference between the two groups (P = 0.529 and P = 0.372) without significant agreement. The disease extent was more severe in the diffuse type than the localized type regarding articular involvement (P < 0.001), muscle involvement (P < 0.001), and tendon destruction (P = 0.010). No statistically significant differences were found between the two groups regarding bone erosion (P = 0.196) or neurovascular bundle encasement (P = 0.165).

CONCLUSIONS

Diffuse-type TSGCTs of digits presented as locally aggressive lesions with larger, multinodular, infiltrative masses exhibiting stronger hemosiderin deposition and more severe disease extents of articular, muscle, and tendon involvement than the localized type.

FDG PET/CT in Tenosynovial Giant Cell Tumor of the Lumbar Facet Joint

ABSTRACT

Tenosynovial giant cell tumor rarely affects the facet joints of the spine. We describe FDG PET/CT findings in a case of tenosynovial giant cell tumor arising from the left L2 to L3 facet joint. The tumor caused osteolytic bone destruction of the facet joint and showed intense FDG uptake with SUVmax of 10.4. This case indicates tenosynovial giant cell tumor should be included in the differential diagnosis of abnormal facet joint FDG accumulation.

[Imminent fracture of the tibia due to an osteolytic lesion caused by an intraosseous tenosynovial giant cell tumor : An unusual clinico-histopathological constellation]

Der tenosynoviale Riesenzelltumor (TSGCT) ist eine seltene gutartige Erkrankung von Gelenkschleimhäuten, Sehnenscheiden und Schleimbeuteln. Wir berichten über die ungewöhnliche Konstellation einer intraossären Manifestation der proximalen Tibia eines Unterschenkelstumpfes nach Burgess-Amputation infolge eines lokal nicht beherrschbaren tenosynovialen Riesenzelltumors des oberen Sprunggelenkes. Die Kürettage des Lokalbefundes und die operative Stabilisierung durch eine intramedulläre Verbundosteosynthese führten zu einer frühzeitigen Rehabilitation der Exoprothesenversorgung mit Wiedererlangung der Patientenautonomie.