Subungual tumors:
benign solid tumors (glomus tumor,
subungual exostosis,
soft-tissue chondroma,keratoacanthoma,
heman-gioma,
lobular capillary hemangioma),
benign cystic lesions (epidermal and mucoid cysts).
malignant tumors (squamous cell carcinoma,
malignant melanoma).
The normal subungual space is very small,
with a thickness of only 1-2 mm As a result,
any tumors of the subungual space,
irrespective of their histologic nature,
can erode into the distal phalanx of the digits.
Clinical Features in subungual glomus tumor:
nail deformity
and change of color beneath the nail and a scalloped defect of the distal phalanx on the radiograph
Features of glomangiosarcomas may include the following:
Size larger than 2 cm
Rapid growth
Deep soft tissue involvement.
Radiography:Radiography
· the tumour is difficult if not impossible to identify - rarely can be seen as a subtle soft tissue density
· may show a marginated osseous erosion or thinning of the adjacent cortical bone
USG and color Doppler:· subungual hypoechoic lesion at the region of maximum tenderness, hypervascularity on Doppler interrogation
USG: a glomus tumor usually manifests as a nonspecific,
solid,
hypoechoic mass beneath the nail,
possibly with associated erosion of the underlying phalangeal bone.
The highvelocity flow in intratumoral shunt vessels causes this lesion to be hypervascular at color Doppler imaging a finding that is specific for the diagnosis
MRI:
MRI:Signal characteristics include:
· T1: low to intermediate signal
· T1 C+(Gd): shows contrast enhancement (usually uniform) due to vascularity
· T2: high signal