Examination revealed a mass on the back side of the left chest wall deep to the angle of the scapula which became prominent on abduction of the arm [Figure 1]. The mass was firm, but became hard on shoulder adduction. A similar mass became visible on the right infrascapular region during the abduction of the right arm, but this mass had not been noticed by the patient. The differential diagnoses considered were intramuscular lipoma, sarcoma, desmoid tumour, fibromuscular tumour besides other soft tissue tumours.