Table 1 Proposed classification of focal hand lesions at our institution into benign, intermediate-grade and malignant lesions
Lesion | Margins | T1w signal | T2w signal | Crossing compartments/involvement of adjacent structures | Bony destruction | Enhancement pattern |
|---|---|---|---|---|---|---|
Benign | ||||||
Ganglion cyst | Smooth | Homogeneously hypointense | Homogeneously hyperintense (fluid) | Nil | NA | Rim enhancement, no internal enhancement |
Epidermal cyst | Smooth | Homogeneously hypointense | Homogeneous hyperintense (fluid) | Nil | NA | Rim enhancement, no internal enhancement |
Fibroma of tendon sheath | Lobulated, preserved fat planes | Intermediate | Heterogeneously hyperintense with low signal areas | Nil | Nil | Small eccentric focus of enhancement |
Focal nodular synovitis | Fairly smooth | Hypointense | Homogeneously hypointense | Nil | Nil | No significant enhancement |
Nodular fasciitis | Lobulated | Intermediate | Heterogeneously hyperintense | Crosses compartments (intra-and extra-compartmental) | NA | Heterogeneous, central non-enhancing foci |
Lipoma | Lobulated, insinuating margins, preserved fat planes | Hyperintense | Homogeneous fat signal intensity | Crosses compartments (intra-and extra-compartmental, involves thenar and mid-palmar spaces) | Nil | Enhancement of thin internal septae only |
Lipofibromatous hamartoma | Lobulated | Hyperintense with curvilinear low signal structures within | Homogeneous fat signal intensity surrounding neurovascular component | Nil | Nil | Linear enhancement of neurovascular components within the lesion |
Haemangioma | Lobulated, insinuating margins | Slightly hyperintense | Heterogeneously hyperintense | Crosses compartments (intra-and extra-compartmental) | Nil | Avid, near homogenous post contrast enhancement |
Schwannoma | Smooth | Isointense (to muscle) | Heterogeneously hyperintense, target sign | Nil | NA | Avid, near homogenous |
Intermediate-grade (histologically benign but locally aggressive with potential for recurrence) | ||||||
Neurofibroma | Lobulated | Isointense | Heterogeneous | Crosses compartments (intra-and extra-compartmental) | Pressure erosion | Avid, near homogeneous |
Desmoplastic fibroblastoma | Lobulated, loss of fat planes | Hypointense | Heterogeneous low signal | Encases adjacent extensor tendon | Nil | Heterogeneous internal and capsule enhancement |
GCTTS | Lobulated | Intermediate | Heterogeneous intermediate-high with low signal areas due to haemosiderin deposits | Crosses compartments (intra-and extra-compartmental) | Pressure erosion | Avid, near homogeneous |
Glomus tumour | Smooth | Intermediate | Homogeneously hyperintense | Crosses compartments (intra-and extra-compartmental) | Pressure erosion | Avid, homogenous |
Malignant | ||||||
Undifferentiated pleomorphic sarcoma | Irregular | Hypointense | Heterogeneously hyperintense | Crosses compartments (intra-and extra-compartmental, areas of infiltration into adjacent muscle) | Nil | Heterogeneous |
SCC | Infiltrative | Hypointense/intermediate | Heterogeneously hyperintense | Invading adjacent muscle, skin, bone | Yes | Heterogeneous |
Malignant bone lesions | Infiltrative | Hypoointense/intermediate | Heterogeneously hyperintense | Invading adjacent muscle, skin, bone, soft tissue component | Yes | Heterogeneous |
Fibrosarcoma | Fairly well defined | Hypointense | Heterogeneously intermediate to low signal | Nil (extracompartmental) | Nil | Heterogeneous, small non-enhancing foci |