Malignant Mixed Tumor - Myoepithelial tumors of soft tissue - Foot and Ankle

Summary
Description

Malignant Mixed Tumor - Myoepithelial tumor. These soft tissue tumors are a rare malignant tumor, whose origin is currently considered to be myoepithelial. These tumors have a predilection for the extremities.

People and Age
Males and females are equally affected. Patients ranged from age 3 to age 83, with a mean of 38.
Symptoms and Presentation
Patients present with a soft tissue mass. Approximately two thirds of the masses are cutaneous, and one third are deep.
Brief description of the xray
The lesion may gradually invade adjacent bones, but initially the tumor is limited to soft tissues.
Tumor Name
Malignant Mixed Tumor - Myoepithelial tumors of soft tissue - Foot and Ankle
Tumor Type
Soft tissue tumors
Benign or Malignant
Malignant
Body region
soft tissue
Most Common Bones
soft tissue
Tumor behavior
aggressive
Complete Information on this Tumor
Introduction and Definition

Malignant mixed tumor is thought to be the most malignant type of myoepithelial tumors, which range from low-grade or benign, high grade and highly malignant. These soft tissue tumors are a rare malignant tumor, whose origin is currently considered to be myoepithelial. These tumors have a predilection for the extremities. Based on reports, approximately 40% of these tumors occur in the lower limb, around 35% in the upper limb, 15% in the head neck and 10% in the trunk.

Incidence and Demographics
This is an extremely rare tumor, with few cases reported in the literature. Reported sizes range from 1 to 20 cm with a mean of approximately 5 cm. Males and females are equally affected. Patients ranged from age 3 to age 83, with a mean of 38.
Symptoms and Presentation

Patients present with a soft tissue mass. Approximately two thirds of the masses are cutaneous, and one third are deep. The size of the mass depends on the delay in seeking treatment and location. Reported sizes range from 1 to 20 cm with a mean of approximately 5 cm. Males and females are equally affected. Patients ranged from age 3 to age 83, with a mean of 38.

Histopathology findings
Histologically the tumors are mixed. The tumors have a lobulated appearance, with cords up epithelioid and spindle cells. Tumors Have a plasmacytoid appearance. The stroma may be chondromyxoid, or hyalinized. The tumors may contain cartilage, bone, or both. Mycoses are frequent, ranging from a few to many dozens per high-power field.

The tumors ranged from low-grade to high grade, depending on the degree of cytological atypia and abnormal cytomorphology. Low-grade tumors are considered to be myoepithelioma, whereas high-grade tumors are classified as myoepithelial carcinoma (when the epithelioid or spindle cells predominate), or malignant mixed tumor (when cytologically malignant cartilage or bone is present).

Immunohistochemistry shows universal reactivity for epithelial markers such as keratins or epithelial membrane antigen.