What Is a Soft Tissue Neoplasm?

Soft tissue neoplasm is generally a generic term describing an abnormal growth, or tumor, that may occur anywhere in the body. Tumors can develop in the skin, connective tissue, and muscles, or may be located in blood or lymph vessels, organs, or the central nervous system. These neoplastic cells may be benign, malignant, or display characteristics of both types. Diagnosis generally involves a patient history along with imaging and microscopic studies. Whether or not physicians treat a soft tissue neoplasm depends on the tumor location and type.

The cells that make up a benign soft tissue neoplasm are generally similar to the originating cells — the tissue surrounding the growth. The neoplasm typically contains denser tissue, which feels firmer than tissue around it. A benign tumor usually has definite borders. The abnormal tissue generally remains localized and often develops within a fat or fibrous capsule. The majority of soft tissue neoplasm tumors are benign.

Malignant tumor cells generally do not resemble the cells of the healthy surrounding tissue. Microscopically, histologists find a large number of cells undergoing different stages of mitosis, as cancer cells typically multiply at much faster rates than normal cells. Cell death, fluid filled capsules, and hemorrhage commonly accompany cancerous neoplasms. Malignancies also generally invade the surrounding tissue, including blood and lymph vessels, providing a means of transporting cells throughout the body.

Fibromatosis is a disorder that causes a type of soft tissue neoplasm with both benign and malignant features. The condition may be hereditary, linked to medical conditions that include diabetes or hypertension, or occur secondary to trauma. While the tumors are usually slow growing, they contain variable cell structures that may or may not resemble the parent cells. These unusual tumors often contain spindle like cells similar in appearance to spindle cell carcinoma. If removed, these tumors may redevelop and present the possibility of metastasis.

A benign soft tissue neoplasm may exist unnoticed for years, though some tumors, themselves harmless, may compress nerve or vascular tissue, producing discomfort, compromised circulation or organ malfunction. Under these circumstances, health care providers and patients may elect surgical reduction or removal. Treating a malignant soft tissue neoplasm may involve chemotherapy, radiation, surgical removal, or a combination of methods, depending on the location, size, and type of tumor.

Treating a soft tissue neoplasm associated with fibromatosis depends on symptoms and possible causes. Similar to other benign tumors, if patients do not experience complications or symptoms, physicians may advise periodic monitoring only. Underlying medical conditions contributing to the disorder generally require treatment.