A 34-year-old male surfer presented with the complaint of bilateral palpable masses on the anterior chest wall, which he had first noticed 2 years previously. He had surfed for more than a decade. On physical examination, an elastic mass was palpated on the lower aspect of the right hemithorax (Fig. 1A). Chest magnetic resonance imaging (MRI) showed poorly defined bilateral areas of low signal intensity anterior to the lower ribs on T2-weighted images, more evident on the right side (Fig. 1B). High-frequency (24-MHz) ultrasound in the right-side area revealed a round, ill-defined, hypoechoic mass (Fig. 1C and D). Similar, but less prominent, findings were obtained for the left hemithorax. The right-side mass was excised surgically. Microscopic examination revealed dermal thickening with fibroblastoid proliferation and collagen deposition. The final diagnosis was “surfers’ knots”.
(A) Photograph of the patient's chest, showing a round mass in the right hemithorax, anterior to the lower ribs. (B) T2-weighted magnetic resonance image showing the low signal intensity of the lesions (arrows). Ultrasonography of the lower right (C) and left (D) hemithoraces revealed hypoechoic masses (arrows) with surrounding dermal (black asterisks) and subcutaneous (white asterisks) thickening.
“Surfers’ knots”, or surfers’ nodules, are acquired, benign, fibrotic connective-tissue nodules that develop in response to repetitive friction between the patient's body and the surfboard. Typically affected tibial tuberosities, foot dorsa, and chest.1,2 Our patient's lower rib cage had suffered intermittent low-grade trauma against the surfboard during paddling. In most cases, the nodules subside or disappear after interruption of the activity. Unusually, the lesions can become infected, painful, and/or permanent, potentially necessitating surgical excision.1,2 The radiological evaluation allows the diagnosis and it is not necessary, in the appropriate context, to perform more invasive procedures.
Conflicts of InterestThe authors declare that they have no conflicts of interest to express.
