The magnetic resonance appearance of surfers' knots: a case report

Abstract

Athletes are at increased risk of developing soft-tissue lesions of the lower limbs. Although the majority of these will be benign, the differential diagnosis is broad and increasingly, doctors are turning to magnetic resonance imaging (MRI) as a first-line investigation when presented with these sorts of lesions, both to narrow the differential diagnosis and exclude malignancy. We report the case of a 28-year-old Caucasian man who presented with 2 soft-tissue lesions of the right foot. History and examination of the nodules fitted with a diagnosis of surfers' knots, an unusual form of acquired, benign, connective tissue nodule that may appear over the tibial tuberosities, dorsum of the feet, and occasionally on the chest of surfers in association with repetitive microtrauma during surfing. MRI findings were consistent with this diagnosis with both lesions exhibiting T1 hypointensity and speckled T2 hypointensity with no significant blooming artifact on gradient echo imaging. When imaged with gadolinium, they demonstrated only mild contrast enhancement. MRI is a valuable tool when investigating athletes with soft-tissue lesions over the lower limbs where the possibility of malignancy must be addressed. In selected cases, MRI may be sufficient to permit a conservative approach to the management of these patients.

Liposurfomas: Acquired bilateral chest wall fibrolipomas in surfers—7 cases

“…The proposed etiology of these growths is incessant low-intensity traumatic compression of subcutaneous tissue, squeezed between the costal margin and the hard deck of a surfboard while paddling in the prone position. 1 , 2 , 3 , 4 These masses gradually increase in size with increased surfing activity and slowly diminish in size with prolonged surfing inactivity. 1 , 3 , 5 These lesions are rather common in surfers, as most “older, long-time” surfers know of someone with these soft symmetric growths on the chest.…”

“… 5 However, the existing descriptions of these entities have be limited to isolated case reports. 1 , 2 , 3 , 4 Additionally, the literature lacks a consistent and clear nomenclature for these tumors. 1 , 2 , 3 , 4 , 6 We propose the term “Liposurfoma” (an infixation neologism) as a new, descriptive, and unambiguous designation for the subcutaneous chest wall fibrolipomas that uniquely affect shortboard surfers.…”

“… 1 , 2 , 3 , 4 Additionally, the literature lacks a consistent and clear nomenclature for these tumors. 1 , 2 , 3 , 4 , 6 We propose the term “Liposurfoma” (an infixation neologism) as a new, descriptive, and unambiguous designation for the subcutaneous chest wall fibrolipomas that uniquely affect shortboard surfers. Liposurfomas should not be mistaken for “Surfers’ knots,” which are symmetric rock-hard dense fibrotic callus-like masses on the lower extremity that affect longboard surfers.…”

“…Liposurfomas should not be mistaken for “Surfers’ knots,” which are symmetric rock-hard dense fibrotic callus-like masses on the lower extremity that affect longboard surfers. 4 , 5 , 7 …”

Surfers' knots in the anterior chest

“…The radiological evaluation leads to the definitive diagnosis and enables us to avoid unnecessary invasive procedures. Sometimes the lesions remain with infection and/or pain, and may require surgical resection . If resection or detailed pretreatment evaluation is needed, CT and MR imaging are useful.…”