What Is an Epithelioid Sarcoma?

Epithelial sarcoma (ES) is a relatively rare clinical epithelioid soft tissue tumor. Its tissue origin is unknown. Some scholars believe that it may be a tumor derived from primitive mesenchymal cells with multi-directional differentiation potential. It has been reported that it accounts for 1.9% of all soft tissue sarcomas, and it is more common in young adults aged 20 to 40. It is more common in males and males and females are 2: 1. One group

Basic Information

Visiting department: dermatology
Multiple groups: 20 ~ 40 years old male
Common locations: The distal type occurs predominantly at the extremities of the extremities, and the proximal type occurs in the head and neck and trunk

Common causes: Unknown cause
Common symptoms: Distal tumors appear as slow-growing nodules or plaques, and proximal tumors appear as multiple deep soft tissue masses.

Causes of epithelioid sarcoma

The cause is unknown. 20% to 25% have a history of trauma or occur on the basis of scars. Like most soft tissue sarcomas, epithelioid sarcomas have no identified risk factors. Trauma may be a factor in tumorigenesis, and the pathogenesis is not clear. There have been reports of loss of heterozygosity for chromosome 22q, and in addition there have been reports of abnormal 8q and 21 monomers.

Clinical manifestations of epithelioid sarcoma

Epithelial sarcoma is more common in men than women. It occurs in young adults aged 20 to 40. It is rare in children and the elderly, but it can occur at any age.
According to the occurrence site, it is divided into distal type (that is, classic type, which is mainly located at the extremities of the extremities) and proximal type (which occurs in the head and neck and trunk). The former is more common. The distal type is more common in the wrist. Tumors appear as slow-growing nodules or plaques. If they invade the dermis, they may cause ulcers. Progressive skin lesions can appear as linear ulcerative nodules, usually less than 5 cm in diameter. It spreads along blood vessels, nerves, and fascia. If large nerves are involved, pain, paresthesia, and even muscle atrophy can occur. Proximal epithelioid sarcomas are older, usually deep multiple soft tissue masses, larger in size, up to 20 cm in diameter, and most commonly occur in the head and neck, pelvic cavity, groin area, perineal para-anal area, and external genital area Such as those who occur in the pelvic cavity are often prone to compression symptoms. Although epithelioid sarcoma is a type of low-grade malignant tumor, because of the early stage of lymph node and lung metastasis, extensive or radical resection is recommended.

Epithelial Sarcoma Examination

1. The classic type of histopathological examination is mainly a nodular tumor mass in the dermis and subcutaneous tissue. The tumor body is composed of epithelioid cells and spindle cells. The surrounding cells can be arranged in a grid pattern. The tumor cell volume is relatively small. Large, can be polygonal epithelial-like cells, with large and deep stained nuclei, atypical, rich in cytoplasm, and deep eosinophilic staining. The other type is spindle cells, which can have sheet necrosis in the tumor and obvious fibrous connectives in the stroma. Tissues can have different degrees of inflammatory cell infiltration. Proximal epithelioid sarcoma tumor cells are mainly composed of epithelioid cells. The cells are large in size, the abnormal shape is obvious, the nuclei are vacuole-shaped, and they are often characterized by striated muscle-like cells. Tumor necrosis can be seen. Classical and proximal types of tumors show similar immunohistochemical findings. Epithelial sarcoma tumor cells are positive for CK and vimentin, and positive for EMA. 2. X-ray, CT, and magnetic resonance (MRI) examinations are recommended for imaging studies to better understand soft tissue involvement. MRI can be used to identify postoperative changes or residuals after tumor resection.

Epithelial Sarcoma Diagnosis

Epithelial sarcoma has a relatively long course of disease. It is relatively common in young male patients, and the location of the disease is mostly at the extremities. The diagnosis is mainly based on pathological examination. One of the histological features is the accumulation of tumor cells into irregular nodular structures. When performing a biopsy of a suspicious subcutaneous lesion in the clinic, it is best to perform an imaging examination first to determine the extent of the lesion.

Epithelial Sarcoma Treatment

Extensive or radical resection is currently the preferred treatment. The tumors of the fingers and toes should be amputated. Those with regional lymph node metastasis can perform regional lymphadenectomy at the same time. Due to the tumor's tendency to spread along the aponeurosis or fascia and metastasize along the lymphatic pathway, it is safer to perform amputations below the elbow joint for larger tumors deep in the palm. Amputation should be performed for relapse cases. Although chemoradiotherapy is beneficial to advanced patients, its value as an adjuvant therapy is for further study.

Prognosis of epithelioid sarcoma

Some literature reports that the overall 5-year survival rate of patients is 68%, the 5-year survival rate of patients with simple rash without metastasis is 75%, the 5-year survival rate of patients with regional lymph node metastasis is 49%, and the distant metastasis survival does not exceed 5 years, and The 1-year survival rate is 46%, and the 5-year survival rate of patients treated with surgery is significantly higher than that of patients treated without surgery, which are 68% and 33%, respectively. Epithelial-like sarcoma is characterized by spreading along the lymphatic pathway, so regional lymph node metastasis is prone to occur, and tumors can also metastasize to the lungs, skin, and brain by blood circulation.
Poor prognostic factors include: men, the elderly, tumors larger than 5 cm in diameter, deep location, nucleus polymorphism and high division activity, vascular and / or nerve invasion, multiple recurrences with / without lymph node metastasis during diagnosis.