Dendritic fibromyxolipoma with intramuscular involvement: A case mimicking slow flow vascular malformation on imaging

Dendritic fibromyxolipoma (DFML) is a benign, very rare, and slow-growing soft tissue tumor commonly involving the muscular fascia of the foot, calf, shoulders, back, or head and neck muscles. Many authors consider dendritic fibromyxolipoma a variant of spindle cell lipoma composed of a plexiform vascular pattern, dendritic cytoplasmic processes, and keloidal collagen. Only a few cases have been reported in the shoulder region, and the presented case represents the second case in English literature whose histopathology showed intramuscular involvement. Recognition of such an entity is essential because it is considered a scarce type of benign tumor that can be mistaken for other aggressive neoplasms of myxoid pathology. We present a case of a dendritic fibromyxolipoma around the right shoulder with intramuscular involvement to the superficial fibers of the right trapezius muscle.