Clear Cell Sarcoma
Clear cell sarcoma (CSS) is a rare melanin-producing soft tissue sarcoma most commonly arising from tendons and aponeuroses of lower extremities, especially feet. Other common locations include ankle, knee, thigh, and hand. It has also been described in gastrointestinal tract and penis. Most patients are young adults (age range: 20 to 40 yrs; median age 30) with a male predominance. It has been referred to as malignant melanoma of soft parts, although it is biologically and genetically distinct from cutaneous melanomas. They present as slowly-enlarging, deep soft tissue mass usually sparing the overlying skin and dermis. The case shown here was resected from the foot of a 25 y/o male. Note the thick keratinized skin of the heel. The tumor is present in the subcutaneous tissues. Grossly, the tumor is lobulated or multinodular, well-circumscribed, firm white or gray mass firmly attached to tendons and aponeuroses. The tumor cuts with a gritty feeling. Areas of hemorrhage, necrosis, or cystic change may be present. Some tumors produce enough melanin to cause brown or black discoloration.