Subcutaneous granuloma annulare: radiologic appearance.
OBJECTIVE
Granuloma annulare is an uncommon benign inflammatory dermatosis characterized by the formation of dermal papules with a tendency to form rings. There are several clinically distinct forms. The subcutaneous form is the most frequently encountered by radiologists, with the lesion presenting as a superficial mass. There are only a few scattered reports of the imaging appearance of this entity in the literature. We report the radiologic appearance of five cases of subcutaneous granuloma annulare.


METHODS
The radiologic images of five patients (three male, two female) with subcutaneous granuloma annulare were retrospectively studied. Mean patient age was 6.4 years (range, 2-13 years). The lesions occurred in the lower leg (two), foot, forearm, and hand. MR images were available for all lesions, gadolinium-enhanced imaging in three cases, radiographs in four, and bone scintigraphy in one.


RESULTS
Radiographs showed unmineralized nodular masses localized to the subcutaneous adipose tissue. The size range, in greatest dimension on imaging studies, was 1-4 cm. MR images show a mass with relatively decreased signal intensity on all pulse sequences, with variable but generally relatively well defined margins. There was extensive diffuse enhancement following gadolinium administration.


CONCLUSIONS
The radiologic appearance of subcutaneous granuloma annulare is characteristic, typically demonstrating a nodular soft-tissue mass involving the subcutaneous adipose tissue. MR images show a mass with relatively decreased signal intensity on all pulse sequences and variable but generally well defined margins. There is extensive diffuse enhancement following gadolinium administration. Radiographs show a soft-tissue mass or soft-tissue swelling without evidence of bone involvement or mineralization. This radiologic appearance in a young individual is highly suggestive of subcutaneous granuloma annulare.
Kransdorf
M J
MJ
Department of Radiology, Saint Mary's Hospital, Richmond, VA 23226, USA.
Murphey
M D
MD
Temple
H T
HT
D000273:Adipose Tissue / Q000000981:diagnostic imaging / Q000473:pathology; D000293:Adolescent; D001842:Bone and Bones / Q000000981:diagnostic imaging; D002648:Child; D002675:Child, Preschool; D003287:Contrast Media; D003952:Diagnostic Imaging; D005260:Female; D005533:Foot Dermatoses / Q000175:diagnosis / Q000000981:diagnostic imaging; D005542:Forearm / Q000000981:diagnostic imaging / Q000473:pathology; D005682:Gadolinium; D016460:Granuloma Annulare / Q000175:diagnosis* / Q000000981:diagnostic imaging; D006229:Hand Dermatoses / Q000175:diagnosis / Q000000981:diagnostic imaging; D006801:Humans; D007089:Image Enhancement; D007868:Leg Dermatoses / Q000175:diagnosis / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging; D008297:Male; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging / Q000473:pathology; D011859:Radiography; D011877:Radionuclide Imaging; D012189:Retrospective Studies; D012867:Skin / Q000000981:diagnostic imaging / Q000473:pathology
D003287:Contrast Media; D005682:Gadolinium