Six-pack tumors!!! This photo shows a fibrosarcoma of the rectus abdominis muscle in a 30 year-old patient. He was asymptomatic with large painless mass palpated lateral to the umbilicus originating from the left rectus abdominis muscle. Fibrosarcomas are a type of malignant soft tissue neoplasms that is composed of malignant and immature proliferating fibroblasts in a collagen background with a strong tendency to recur locally after resection. They are of mesenchymal cell origin in which histologically the predominant cells are fibroblasts that divide excessively without cellular control. Operation was done with a total excision of the mass and removal of the rectus abdominis muscle to avoid local recurrence. Photo credit : @moudymad